Thursday, July 16, 2015

The great divide in how researchers manipulate fruit flies

How do you manipulate your Drosophila, Paint brush or watch maker's forceps? You Tell me!

I bet when you read "manipulate" you thought I meant genetic manipulation, eh?

So last night while I was "pushing flies" - collecting flies for a genetic cross (mating scheme), - I was switching back and forth between my two favorite instruments (paint brush with short hair and forceps) to move around anesthetized flies (sorting based on genotype, sex, etc). For some reason (even though I have been a fly pusher for 18 years) I started to think about whether the brush or forceps was more efficient. After all, I have sorted (at a rough guess) several hundred thousand flies (or more?) during this time. Small efficiencies could save huge amounts of time.

For me I generally use forceps when I am collecting small numbers of distinct individuals (based on genotype & sex) in a large pile on the anesthesia plate (a plate with a porous surface where we pump carbon dioxide through to knock out flies). I use the brush when it is many more individuals, and there are (relatively speaking) more of them, like for "virgin" collecting (collecting very young females who have not yet mated with a male, and so are not storing sperm).

So I wanted to know from fly peeps around the world; paint brush? forceps? other? Why this choice?


Wednesday, June 17, 2015

The struggle to reproduce scientific results and why (scientists and everyone else) should be happy about it.


Once again there has been a spate of articles in the "popular" and scientific press about issues of reproducibility of scientific studies, the reasons behind the increase in retraction rates, and incidences of fraud or increased carelessness among scientists. It has been repeatedly pointed out that scientists are just people, and thus subject to all of the same issues (ego, unwillingness to accept they are incorrect etc), and that we should accept that science is flawed. This has also raised some to ask whether the enterprise and practice of science is broken (also see this). However, I think if you look carefully at what is being described there are many reasons to suggest that the scientific endeavor is not only not broken, but is  showing an increased formalism of all of the self-correcting mechanisms normally associated with science. In other words, reasons to be optimistic!

Yes, scientists are (like all of us) individually biased. And as many authors have pointed out in the current environment of both scarce resources and desire (and arguable need, to secure resources) for prestige, some scientists have cut corners, failed to do important controls (or full experiments) that they knew they should or used outright fraud. However, what I think about most these days is how quickly these issues are discovered (or uncovered) and described both online and (albeit more slowly) in the formal scientific literature. This is a good thing.

Before I get into that, a few points. It seems like articles like this in the New York Times may make it seem like retractions are reaching epidemic levels (for whichever of the possible reasons stated in the paragraph above). However such a claim seems overly hyperbolic to me. Yes, there seems to be many retractions of papers, and thanks to sites like retraction watch, these can be identified far more easily. They have also pointed out that there seems to be an increase in retraction rates during the past five years. I have not looked carefully at the numbers, and I have no particular reason to dispute them. Still, as I will discuss below, I am not worried by this, but it brings me optimism about the scientific process. Our ability (as a scientific community) to correct these mistakes is becoming quicker and more efficient.

 First (and my apologies for having to state the obvious), but the vast majority of scientists and scientific studies are done with deliberate care of experimental methodology. However this does not mean mistakes do not happen, experiments and analyses may be incorrect, interpretations (because of biases) may be present in individual studies. This is sometimes due to carelessness or a "rush to publish", but it may as well be due to honest mistakes that would have happened anyways. As individuals we are imperfect. Scientists are as flawed as any other person, it is the methodology and enterprise as a whole (and the community) that is self-correcting.

Also (and I have not calculated the numbers), many of the studies reported on sites like Retraction Watch are actually corrections, where the study itself was not invalidated, but a particular issue about the paper (which could be as simple as something being mis-labeled). I should probably look up the ratio of retractions:corrections (and my guess someone has already done this).

One of the major issues that is brought up with respect to how science is failing is that the ability to replicate the results found in a previously published study can be low. As has been written about this issue before (including on this blog), perfectly reproducing experiment can be as difficult as trying to get the experiment to work in the first place (maybe harder). Even if the effect is being measured is "true", subtle differences in experimental methodologies (that the researches are unaware are different) can cause problems. Indeed, there are at least a number of instances where the experimental methodology trying to reproduce the original protocol was flawed (I have written about one such case here). While I could spend time quibbling about the methodology used to determine the numbers, there is no doubt that there is some fraction of papers that are published, where the results from experiments are not repeatable at all, or are deeply confounded and are meaningless. I will say, that most of the studies looking at this take a very broad view of "failure to replicate". However, I have no doubt that research into "replication" will increase, and this is a good thing. Indeed, I have no idea why studies like this would suggest that studies with "redundant" findings would have "no enduring value".


So with all of these concerns, why am I optimistic? Mostly because I do not think that the actual rate of fraud or irreproducibility is increasing. Instead, I think that there has been an important change in how we read papers, detect and most importantly report problems with studies and the general process of post publication peer review (PPPR). Sites like retraction watch, pubpeer, pubmed commons, F1000 as well as on individual blogs (such as here and here) are enabling this. Not only are individual scientists working together to examine potential problems in individual studies, but these often lead to important discussions around methodology and interpretation (often in the comments to individual posts). This does not always mean that the people making the comments/criticisms about potential problems are always correct themselves (they will have their own biases of course), but potential issues can be raised, discussed by the community and resolved. These may lead to formal corrections or retractions in a few cases. Most of the time it usually leads to the recognition that the scope of impact of the study may ultimately be more limited than the authors of the original study suggested. It also (I hope) leads to new and interesting questions to be answered. Thus, the apparent increase in retraction rates and reproducibility issues most likely reflects an increased awareness and sensitivity to these issues.  This may be (psychologically) a similar issue where despite crime rates decreasing, increased scrutiny, vigilance and reporting in our society make it seem like the opposite is happening.

I also want to note that despite comments I often see (on twitter or in articles) that pre-publication peer review is failing completely (or is misguided), I think that it remains a successful first round of filtering. In addition to serving (and having previously served) as associate editor on a number of journals (and having reviewed papers for many many more) I would estimate that 80% of reviews I have seen from other authors (including for my own work) have been helpful, improve the science, the interpretation and clarity of communication. Indeed as a current AE at both Evolution and The American Naturalist the reviews for papers I handle are almost always highly professional, very constructive and improve the final published papers. Usually this results from pointing out issues of analysis, potential confounding issues in the experiments and concerns with interpretation. Often one of the major issues relates to the last point, reviewers (and editors) can often reduce the over-interpretation and hyperbole that can be found in initial submissions. This does not mean I do not rage when I get highly critical reviews of my own work. Nor does it mean that I think that trying to evaluate and predict the value and impact of individual studies (and whether it has any part in the review process and selection for particular journals) remains deeply problematic. However, in balance my experience is that this does improve studies and remains an important part of the process. Further, I do not see (despite the many burdens on the time of scientists, and that reviewing remains unpaid work) evidence for a decline in quality of reviews. Others (like here and here) have said similar things (and probably more eloquently).

As for the replication issues. This is clearly being taken seriously by many in the scientific community, including funding agencies which are now setting aside resources specifically to address this. Moreover, many funding agencies are now not only requiring that papers funded by them be made open access within 12 months of publication, but (and along with a number of journals) are requiring all raw data (and I hope soon scripts for analyses) to be deposited in public repositories.


I think the scientific community still has a lot to do on all of these issues, and I would certainly like to see it happen faster (in particular with issues like publishing reviews of papers along with paper, more oversight into making sure all raw data, full experimental methodology and scripts are made available at the time of publication). However, in my opinion, it does seem like the concerns, increased scrutiny and calls for increased openness are all a part of science and are being increasingly formalized. We are not waiting decades or hundreds of years to correct our understanding based on poor assumptions (or incorrectly designed or analyzed experiments), but often just months or weeks. That is a reason to be optimistic.

note: Wow, it has been a long time since my last post. I can just say I have moved from one University (Michigan State University) to another (McMaster University) and my family and I are in the process of moving as well (while only ~400km, it is from the US to Canada...more on that in a future post). I will try to be much better after the move next week!

Saturday, September 27, 2014

Sufficient biological replication is essential for differential expression analysis of RNA-seq

I just took part in a twitter discussion about the trade-offs between sequencing depth and number of independent biological replicate (per treatment group) for differential gene expression analysis. While there are applications of RNA-seq where  sequencing deeply (more than say 50 million reads for a given sample) can be important for discovery. However, most researchers I interact with are interested at some level with differential expression among groups (different genotypes, species, tissues, etc).  As with everything else that requires making estimates and quantifying uncertainty for those estimates (minimally necessary for differential expression), you need independent biological samples within each group as well. The ENCODE guidelines suggest a minimum of 2 biological replicates per treatment group (well they do not say "biological" replicates, but I will give them the benefit of the doubt).

However, numerous studies have demonstrated that 2 is rarely sufficient (see links below). I have no idea where the ENCODE got this number from. Generally you want to aim for 4 or more for simple experimental designs. There are numerous studies that have shown this (both by simulation and by rarefaction analysis). These also demonstrate that on balance, beyond a certain read depth per sample (somewhere between 10-25 million reads per sample) there is diminishing returns for rare transcripts (in terms of differential expression), and that it is better to do more independent biological replication (say 5 samples each at 20 million reads) rather than more depth (2 independent biological samples at 50 million reads each). The exact number depends on a number of factors including biological variability (and measurement error) within groups, as well as experimental design. A number of tools have been developed to help folks with figuring out optimal designs.

Here are just a few such studies (there are many more, just wanted a handful for the moment).

http://www.ncbi.nlm.nih.gov/pubmed/24319002
http://www.ncbi.nlm.nih.gov/pubmed/25246651
http://www.ncbi.nlm.nih.gov/pubmed/22985019
http://www.ncbi.nlm.nih.gov/pubmed/22268221
http://www.ncbi.nlm.nih.gov/pubmed/23497356

Check out
http://bfg.oxfordjournals.org/content/early/2011/12/30/bfgp.elr041.full.pdf+html
for a brief and succinct discussion of these and other issues.

And yes, depending on your questions, read length (and PE for SE ) also contribute!

Wednesday, September 24, 2014

Implementing Discovery

This post is the first (of two) about my suggestions for how to implement "open discovery" for answering scientific questions, but in a way that does not completely alienate current professional scientists. In particular because of the current system of how "credit" for answering questions translates to prestige which directly translates to tangible materialistic considerations (raises, being invited to give talks, grants, employment).

Some Background

Early last week I saw a tweet by @caseybergman:


This was posted in the context of how Casey plans to implement his scientific research in the coming months and years. Casey was one of two folks who introduced me to twitter as a serious means for scientific communication, and I have found in our 1-1 conversations to get a lot out of it, so I went ahead and read the book he mentioned by Michael Nielsen (http://michaelnielsen.org/), Reinventing Discovery. I was very inspired by the book.

 I am not very efficient at summarizing books, but you can read the first chapter for free online. It does a good job of summarizing the main message of the book. Essentially, scientific discovery can be profoundly changed for the better (and in particular made much more efficient and productive), by opening up the ongoing research endeavour to the world, for any and all to actively and concurrently participate in. This goes well beyond (but does include) sharing all data, source code and manuscripts, which (if done) is after most of the actual research has been completed. The approach advocated in the book is about setting up the important problems in the field (with some progress of research on those problems), and inviting all scientists (professional and lay scientists alike) to participate in answering the questions.

One of the main examples that Nielsen cites throughout the book is from the Gower's polymath project, that used an open collaborative framework (on Gower's blog) to find a mathematical proof that had previously eluded the mathematical community. I will not go into the details from the book or blog post, but will just point out that this turned out to work very well, and efficiently, and went from asking the question (with some progress Gower had made) to answering it in less than 40 days. This was not surprisingly followed up by writing up the results in a scientific paper.

The book is full of various examples of how scientifically or computationally challenging problems have been addressed in the open on the internet. I will let you read the book and decide for yourself. While it is fair to say I was already primed (see here and here) for such a vision of scientific discovery, I did realize how much more potential  there was.

But...

 Such an approach flies in the face of how many (including within the scientific community) perceive how science is done, and how credit for solving scientific problems is garnered. While both the process of scientific discovery, and communication of those discoveries has changed a great deal over the past few hundred years, it is fairly clear that more "recently" (post World War II anyways) a particular system has been built up for professional academic scientists (those who do their research and teach at Universities and other institutes of higher learning).

There are two parts to the "standardization" (or possibly calcification) of scientific discovery and communication that bear considering, and why an immediate transformation to a completely open process of scientific discovery may not be easy (at least from the perspective of academic scientists).

Current practices in scientific communication

First is the means of scientific communication that has become accepted (and calcified). When an individual or group of scientists working on a particular problem have made (in their eyes) sufficient progress on a problem they will usually communicate this in the form of a scientific paper. This is commonly done via submitting a manuscript to a journal. An editor sends it out for peer review (to other experts in the field), who evaluate it for technical correctness, soundness of logic, and for many journals for "novelty" of the ideas and findings. If some of these criteria are not met, the manuscript may be recommended for rejection, otherwise for corrections (revisions), or for acceptance.  For a given manuscript this process may repeat several times at the same journal, or at different journals (if rejected from the first journal).

Scientific prestige and current measures of productivity do translate to material benefits (for the scientist).

 Assuming the paper is accepted, it is published in a scientific journal. The publication of the article itself, the place it is published and the attention it receives (both in the scientific literature via citations, or in the popular press) all can "matter" for the nebulous ideas of "credit" and "prestige" for the scientists who did the work, and wrote the paper. Indeed these ideas of "credit/prestige" are at the heard of how scientists are evaluated at universities. Our employment (getting a job in the first place), career advancement, salaries, garnering grant support, etc.. can all depend (to varying degrees) on where and how much you publish. These are proxies for "research productivity".

Who gets credit for scientific breakthroughs.

The other piece of this (and related to the idea of prestige), is that much of thescientific work, and the "important breakthroughs" are done by lone individuals or small research groups. These "important breakthroughs" are often popularized in textbooks and the media as having come out of no where (i.e. that the research is completely unlike what has been done before). However, most of the time it is pretty clear that (like with general relativity, or Natural Selection), related ideas and concepts were percolating in the scientific community. That is not to play down the genius of folks like Einstein or Darwin, just that these breakthroughs rarely occur in an extreme intellectual vacuum.

 The problem is, that even in modern Universities, research institutes and funding agencies, these sorts of ideas persist, and the prestige for addressing a particular research problem go to one or a few people. This is despite the fact that much highly related work (that set up the conditions for the breakthrough) happened before. Even for multi-authored papers, it is usually just a few of the authors that garner the credit for the findings/discoveries. In my field this is usually the people who are the first and final authors on the manuscript. The prestige associated with this leads to all sorts of benefits (like the ones mentioned above), as well as being invited to give talks around the world at conferences and universities.  Thus there is a real materialistic benefit in modern academic science for garnering this prestige (and getting the right position as an author).

The problem is, in many fields, what defines author position can vary considerably. In my field the first author is usually for the person who has provided the most work, and insight into the research in this paper, and the last position for the "senior scientist" whose lab the work was done in (and usually garnered funds, and sometimes came up with the ideas). However the difference between the contribution between the first and second author (or subsequent sets of authors) is rarely quantified, or clear.

This difference in authorship position means a great deal for material concerns to the participating scientists though. Being first author on a paper in a prestigious journal (even if there are 40 authors on the paper) may be necessary (although rarely sufficient) to get a job at a major research university. However being third author on each of three papers in that same journal (even if there are only 4 authors on each of those papers), will not carry nearly as much weight.

Thus the issues of how to make an open collaborative discovery system for scientific research is at odds with the current (socially constructed) system for academic awards for professional scientists. This is by no means insurmountable. While "Reinventing Discovery" only touched on some possible solutions, in the coming days I will post about one possible idea towards meeting such goals, but in such a way that can be easily integrated into the current system of publishing (but maybe not rewards).




Saturday, May 10, 2014

Can we really "afford" not to estimate effect sizes


A recent post over on DATA COLADA suggested that the sample sizes required to estimate effect sizes appropriately are prohibitive for most experiments. In particular this is the point they made:

"Only kind of the opposite because it is not that we shouldn’t try to estimate effect sizes; it is that, in the lab, we can’t afford to."

In response to their post, it has already been pointed out that even if an individual estimate (from a single study) of effect size may have a high degree of statistical uncertainty (in terms of wide confidence limits), that a combination of such estimates across many studies (in a meta-analysis), would actually have pretty reasonable uncertainty (and far smaller than for any single experiment). 

I think that there are a couple of other basic points to be made as well.

1) There is no reason not to report the effect size and its confidence intervals. These can be readily computed, so why not report it and associated confidence intervals? Even if some folks still like to focus on trying to read tea-leaves from p-values, the effect size helps in the interpretation of the biological (or other) effect of the particular variables under investigation.

2) The main argument from the DATA COLADA blog post seems to be from the simulation they summarize in figure 2. There are two important points to be made from this. First for all the sample sizes they investigate in figure 2 the confidence intervals do not overlap with zero. So the effect sizes (for all of the sample sizes reported) also demonstrate the "significant effect", but with considerable additional information. In other words, there is no loss of information by just reporting the effect sizes with confidence intervals. You can always do a formal significance test as well, although most of the time it will not provide further insight.

3) The "acceptable" width of the 95% confidence intervals is a discipline specific issue (and the CIs are a function of not just sample size, but of the standard deviation for the observed data itself). 

So please report effect sizes and confidence intervals. Your field needs it far more than another example of P < 0.05.


Tuesday, February 25, 2014

Why would any scientists fuss over making your data public and accessible?

Well colour me naive. When PLoS announced their new data archiving policy a few days ago, I hardly felt like it was a "big deal". Providing a public archive of raw data used in a published study seems like a no-brainer (except in very limited circumstances with medical records, location data for at risk species, etc), and is becoming standard practice, right? Clearly my naivete knows no bounds, given some of the really negative reaction to it. (here is one example, while discuss the issue a bit more broadly here ).

In the fields I am most active (at the intersection between Genomics, Genetics and Evolution), there have been numerous recent (and successful?) efforts to make sure data associated with studies becomes archived and publicly available in repositories. While they (the repositories) are not perfect, data archiving seemed to be working and generally useful, and I was always happy to do so myself. Yes some of the issues with getting the data and meta-data formatted for NCBI GEO (or SRA) could be annoying at times, but this was such a minor concern relative to all of the other efforts in collecting and analyzing the data, writing the manuscript (and getting it accepted for publication) that the day spent so that it would be available to other researchers long term seemed pretty minor. Other scientists have always sent me reagents and (when they could find it) data, so this seemed like an easy way to be helpful and inline with the scientific process (and hopefully progress).

More importantly, having tried to get data from other researchers over the years (with huge numbers of "old hard drive failures" always seeming to be the reason why it could not be made available to me). I have recently been involved with a large meta-analysis of previously published data. Rarely was the raw available, and because only summary statistics were available (rarely with associated measures of statistical uncertainty), we were very limited in what analyses we could do. There would be so much more we could do if the raw data had been available.

 So, I do not want other researchers to have to deal with these frustrations because of me. By archiving data generated by myself or members of my lab, other researchers could get it without hassling me, and I would not have to worry about finding it at a later date (like 10 years down the road), where it may have taken far more time to recover, then putting it in a repository in the first place.

 In Evolutionary biology, most of the journals simultaneously started a data archiving policy (generally associated with DRYAD) a few year ago, I was quite happy. Not only did I put data from new studies up in DRYAD, but also from my older studies (see here). I naively expected most evolutionary biologists to do the same. After all, there are many long term data sets in evolutionary biology that would be of great value, in particular for studies of natural selection, and estimating G matrices, where there is still much active methodological development. Some of the publications generated data sets requiring heroic efforts, and would be a huge community resource.

 So I was a little surprised when DRYAD was not rapidly populated by all of these great legacy datasets. I think that folks "hoarding" data are a very small minority, and the majority of folks were just very busy, and this did not seem like a pressing issue to them. In any case, I have also spent some effort at my institution (Michigan State University) discussing such issues with students about the importance of data archiving. All of the benefits seem obvious, making our science more open, and making our data available for those who may be able to address interesting and novel questions in the future. Fundamentally, it is the data and the analysis (and interpretation) that represents much of the the science we do. Our scientific papers representing a summary of this work itself. Better to have it all (data, analysis and interpretation) available, no?

So, when PLoS made the announcement, this seemed like par for the course in biology. Funding agencies are mandating data management and sharing plans, other journals too. So who could be either shocked or dismayed by this?

Like I said, I can be naive.

Even after reading (and re-reading) posts (above) and discussion threads about concerns, I am still baffled. Yes there will be a few "corner cases" where privacy, safety or conservation concerns need to be considered. However for the vast majority of studies in biology this is not the case, or the data can be stripped of identifiers or variables to alleviate such issues, at least in many of these situations.

So what's the problem?
Does it require a little work on the part of the authors of the studies? Perhaps a little. However, I always remind folks in the lab that the raw data they generate, and the scripts they use for analysis will be made available. I find that to my benefit the scripts are much easier to read. Furthermore, keeping these issues in my mind makes it that much easier to get it organized for archiving. The readme files we generate make sure we do not forget what variable names mean, or other such issues. Handling data transformations or removing outliers in scripts means we can always go back and double check the influence of those observations.

In their post, DrugMonkey suggests that the behavioural data they generate in their lab is too difficult to organize in such a fashion as to be broadly useful. While I agree that the raw video (if that is what they are collecting) still remains difficult (although perhaps figshare could be used, which is what we will try for our behavioural trials), we find that the text files from our "event recordings" are very easy to post, organize and generate meta-data for. Does the data need to be parsed from its "raw" format, to one more useful for analysis? Sure, but we will also supply (as we do in our DRYAD data packages) the scripts to do so. Perhaps there is something I am missing about their concern. However, I do not concede their point about the difficulties about organizing their data for archiving. How hard should it really be to make such files useful to other experts in the field?

Even for simulations, we supply our scripts, configuration files, and sometimes data generated from the simulation (to replicate key figures that would take too long to generate by replicating the whole simulation).

It is always worth reminding ourselves (as scientists) of this quote (attributed to Sir William Bragg):

"The important thing in science is not so much to obtain new facts as to discover new ways of thinking about them"

Monday, November 11, 2013

pictures in my head: What is that on the wing of the fly? What does it tell us about adaptation?

Over the past week or so, there has been an absolutely amazing image that has made the rounds on the internet of a fly (Goniurellia tridens)with markings on its wings reminiscent to many viewers of ants. 



As described in these blog posts and articles (Anna ZachariasJerry Coyne, Morgan Jackson, Andrew Revkin, Joe Hanson, also here and here) about it, the assumption is that these images are used by this fly to mimic the ant (or more likely a spider- more on this below), to act to ward off potential predators. However, there has been relatively little discussion about the context in which it uses it (but see Morgan Jackson's post), and demonstration of its adaptive utility. As pointed out by many evolutionary biologists, and discussed in detail by Gould and Lewontin in one of the most famous papers in evolutionary biology (The Spandrels of San Marco and the Panglossian paradigm: A critique of the Adaptationist programme), it is easy to make a "just so" adaptive story, but as scientists we need to perform critical experiments demonstrating the adaptive utility of this picture on the wing.

As numerous commenters on the blogs and on twitter have pointed out this fly is part of the family of true fruit flies (Tephritidae), that include several that are known to startle jumping spider (causing them to do a short retreat). This retreat is likely because the flies have evolved to mimic aggressive behaviours of the spiders themselves. This work was initially described over 25 years ago in a pair of papers in Science (One by Erik Greene, Larry Orsak and Douglas Whitman. The other paper by Monica Mather and  Bernard Roitberg). These papers beautifully demonstrate the adaptive utility of markings on the wing combined with a rowing action of the wings that could achieve this mimicry. Neither the markings on the wings nor the rowing behaviour alone were sufficient to induce the aversion behaviour in the spiders (the spiders retreat). Indeed those of us who took biology courses in University in the early to mid 1990's probably remember this example being taught to us. What's more is that it seems to be fairly wide spread among species in this family of flies (each research group used a different species of Tephritid fly and spider.) Another paper (Oren Hasson 1995) tested about 18 different species of jumping spiders with the medfly (also a Tephritid), and showed that most spiders responded with the retreat as well. This suggests that this adaptive wing morphology and behaviour combination is probably pretty ancient.

Here I want to show you a video of a picture-winged fly, with a jumping spider. This fly is from a totally different family of flies (the picture-winged flies Ulidiidae (formerly Otitidae)) than the ones discussed above (Tephritids), but apparently does the same thing to startle jumping spiders (as a way of escaping being eaten) as the true fruit flies. 

 A few years ago, when I was hosting a lab bbq in my backyard, we were lucky enough to get to watch the intricate little behavioural "routine" between a fly and a jumping spider (in this case the bold jumping spider, Phiddipus audax). The spider approached the fly, got into its attack posture, and then the fly did its "wing rowing" display, the spider "retreated" (took a short jump back), and the fly took off, successfully evading getting eaten. Not too shabby, plus how often do you get to watch this for real!

Two years ago I got to watch this happen again, and this time I happened to have some collecting vials. So I collected the flies! I then put the fly in a small dish with a jumping spider  (the zebra spider Salticus scenicus) so I could get some simple video of it. Here it is in all its grainy, low quality glory.





Given that I am not a great entomologist, I sent a picture of the fly off to a colleague (Jim Parsons, our collection manager in the MSU Entomology department), and he pointed out to me that this was not a true fruit fly (Tephritid) at all, but a picture-winged fly (from the family Ulidiidae). This particular fly is called Delphinia picta.



This was clearly really exciting, as it shows the potential for a whole other group of flies demonstrating a similar set of anti-predation behaviours. While both of these families belong to the same super-family, their last common ancestor lived probably 75 million years ago (give or take several million years).  Is this an example of two different groups of animals independently adapting the same way (convergence) to a similar selective pressure (not getting eaten)? Or is it an adaptation that has survived for millions of years across many species? Finally the possibility exists that some aspects of the behaviours and wing spots allow this to evolve as an anti-predator adaptation over and over again (parallelism)? Whatever it is, it suggests that something even deeper and cooler has happened in evolution, and it will be great to figure this out (hint to new graduate students seeking projects!). As my colleague Rich Lenski mentioned to me (when I showed him this video), it also makes one think carefully about the appropriate "null hypothesis" regarding putative adaptations!

  In my lab, one of the things we study is the fly Drosophila melanogaster, and how it evolves in response to potential predators, including jumping spiders. Drosophila is the little fly that you used in high school or university biology.  Many call it a fruit fly, even though it isn't (pomace fly and vinegar fly are both used as its common names). For Drosophila we have never observed this kind of behaviours at all. However Drosophila does display a pretty wide range of behaviours, and we are writing up a paper about it right now. For a taste of some of it, check out my graduate students poster over on figshare describing some of the behaviours. 




Let me know if you want more, and maybe I can post some additional video. However, to whet your appetite here is another related video that we posted a while ago to youtube (of flies with a mantid). The action starts at about 2:30 into the video.




Thursday, October 24, 2013

My thoughts for the panel on "open access and the future of scholarly publishing"

On Tuesday, as part of open access week I participated in a panel "Publishing, Authoring, and Teaching in the Evolving Open Access Environment: A Panel Discussion". While this is not a word for word write-up, this is more or less the gist of what I said.

When I was asked whether I would be willing to participate in a panel discussion here at Michigan State University on the role of open access journals and the future of academic publishing I said yes. While I am not convinced I am particularly knowledgeable about it, I thought that it  provided an opportunity to collect my thoughts, a manifesto of "how I communicate science, and why I do it that way".

While I do tweet and blog about aspects of open science, including open access publishing, I am not one of the most outspoken advocates, and only a moderate practitioner. I publish, review and edit in/for open access journals, but not exclusively. I continue to publish in many "subscription journals" that represent the journal of record for my field, or those with some inferred "prestige". I do happen to regularly discuss issues about open science, including open access publishing with many folks, but as you will see I am not sure where I fall down on it.

I work in the basic life sciences, at the interface of evolutionary biology, genetics and genomics. The norms of scholarly communication differ substantially from field to field, in terms of what is considered productive scholarship, books VS. articles, authorship and a host of other issues. Even within the natural sciences, scholarly communication differs between biology and say physics. So, my experience and understanding remains narrow and I claim no expertise.

I think that the future of scholarly publishing will be open access, in some shape or form. That is, the majority of published manuscripts will eventually be freely available to anyone with internet access. How do we get there? I have no idea. Will this be due to broad mandates from funding agencies and  Universities to deposit manuscripts into repositories? Will journals generally agree to make content freely available after a fixed amount of time (6-12 months) - so called green open access? Or will gold open access become the norm where authors pay to have work reviewed or published?  Likely a combination of these and other approaches, but I am not good at such guess work.

So why do we care about OA in the first place?

Several reasons.  

This has been discussed by many before, so my thoughts on this are brief. For more detailed thought, check out Peter Suber's book "open access".

If you happen to be on the MSU library site, and happen to click the faculty page you will see on the right hand side links to a number of things including "Crisis in Scholarly Communication". The discussion on these pages is about the increasingly difficult access to scholarly publications. The basic reason is that while academic library budgets tend to be relatively flat, the cost of subscriptions to academic journals continues to increase very rapidly. Often this is because many of the subscription (i.e. for profit) publishers are commonly practicing bundling of journals. So if you want journal A, you also have to subscribe to x (pick a country) journal of y (sub-field) of z (pick organism).

Why should scholarly work be behind a paywall, and thus inaccessible. 

In particular for scientific (and medically relevant work) it could benefit researchers, patients and doctors (who would otherwise not have access). Open access allows the whole public to look at the research if they so choose. This also removes one small barrier in the perception of the ivory tower, and rebuilding some trust with the public (more on this later).

Who is paying for the research? Generally not the publisher making money for the paper.

 At least in the sciences, research is usually paid from grants from federal agencies, and salaries are paid from those grants, or from the University (such as MSU) which in part comes from state allocations and tuition dollars. The manuscript is then reviewed by referees usually for free (as part of our scholarly role) including as scientific editor (which is also not usually a paid position, at least for associate editors). Under the current system most referees get nothing (neither money nor any other incentive) for this essential service, and their pay is from their institution (and does not depend upon them performing this service). The publisher may maintain the electronic system to shuttle the draft manuscript to the referees, and if accepted performs copyediting and typesetting.  There are exceptions to the rule (I have had absolutely excellent editing advice on both the writing and communicating the science for a recent paper in Trends in Genetics from the managing editor for instance), but this has not generally been the case for me.

Thus the publisher is making a great deal of profit, despite having only done a fraction of the work. They (not the authors) retain the copyright on the work. This is potentially a big problem.

How I got into this

I will tell you about how I got engaged with the ideas of open access publishing, as a small part of the larger endeavor to make science in academia more open, transparent, reproducible, and in such a way that scientific ideas and data are communicated more quickly and effectively. But I also will describe many of the remaining stumbling blocks that relate to views of open access journals specifically, and the nefarious concept of prestige in publishing and how that influences hiring, grants, and promotion.

The crisis in scholarship is much bigger than open access.

Why is there a crisis?

While open access of published work is certainly a factor in the crisis in scholarly communication, and the one I will speak the most about today, it is not the only factor (issues with peer review, reproducible research, sharing of data and code, etc..).  There have been a slew of articles including a few in the Economist and the Guardian in the last few weeks on aspects of this crisis. Essentially it is argued that scientific research is in a tailspin, there is no effort to do quality science, and everything is about quantity of papers and prestige (i.e. spin) with little effort to make sure the work is valid, well reviewed or replicated. That is the incentive system for scientists is completely out of whack with the process of good science

Is there a crisis? I am a skeptic and cynic, so I think there are some real concerns. However the little optimist voice in my head also points out that there are some great opportunities as well to help to not only resolve this crisis, but make science/scholarly research better, and far more dynamic. Indeed there is a vocal and active community trying to make this all much better.

Before I delve into the specifics about the need for open access (and what might be stopping some of us from diving into it completely), I want to speak about the larger crisis of the scholarly enterprise in general, and how open science initiatives can fix this. In my mind this comes down to an issue of trust. Trust between collaborators. Trust between scientists working in the same field. Trust between researchers at different stages of their careers (graduate students, post-docs and PIs). Finally, we need trust between scientists and the general population. Not just how the public perceives scientists (and scholars in general) and the work they do, but that we do our science in an open way that leads to the appropriate self-correcting mechanisms. However, even beyond the large number of anti-science and anti-intellectual movements out there, there has been a substantial loss of trust in how scholars operate, and what motivates us.

Between the large number of research articles that get picked up by the popular press about "cures" or of genes for "this that and the other", only to have such research shown to be largely (or entirely) incorrect a few months later.  Combine this with the many news articles that point out the lack of repeatability of scientific studies, or examples of scientific fraud and misconduct, our lay audience (and those that ultimate help pay for our research and salaries) are perhaps becoming quite skeptical. The lack of access to the scientific literature for the public due to paywalls (from subscription based journals)  is simply another large nail in the coffin for the trust that scientists and science communicators have been trying to build with the public.

Frankly our motives are questioned, and not just by the public at large. They are also questioned by our graduate students too. As undergraduates (or from watching nature shows) they see this amazing wonderful universe to study, but then come to do research as graduate students and realize that a business model has taken place with a culture of "scientific stardom" being the goal for many. Worse than that, they see a perverse incentive system where quantity of publications and prestige over where articles are published has taken hold, and the overall quality of scientific research is the perceived victim (has this been evaluated?). There are many folks to blame, including university administrators, the "high prestige" journals, etc, but we first need to look at ourselves (practicing scientists) for accepting and adopting this system as it has developed into the status quo.

So how do we fix it?

Let's think about the aspects of open science. Not only do we need to communicate what we do more effectively, but we need to make everything far more transparent.

Open Science

Much has been written about open science, and the open science movement. It has many goals, but I would say in general the two most important ones are to increase transparency of the scientific process and to speed (and open) up science communication. There are many aspects going all of the way from open "lab notebooks" (here and here). Submitting pre-prints (papers prior to peer review and formal acceptance at a journal) to repositories to speed up science communication. Increasing openness in peer review, so that all can see the comments of the peer referees and editors. This can include pre and post publication review (pubpeer, pubmed commons). Sharing of raw data associated with research papers as well as all of the details of how the analysis was performed (the computer code associated with it). It all comes down to the fact the published paper is not the science itself, but a precis (or an advert) for the actual scientific work. All of the data, the work and even the peer review process itself is part of the scholarship of science. Making some or all of this available will not only help with transparency, but will speed up the scientific process. Having access to the raw data may also help to answer all sorts of new and interesting questions. I have always loved this quote by Sir William Bragg:

"The important thing in science is not so much to obtain new facts as to discover new ways of thinking about them"

Open Access and the entanglement of scholarly publishing with prestige and other incentives

Crossroads for publishing

At least in the life sciences, it is clear that publishing articles in "high profile" journals like Nature, Science, PNAS (and a few others) can make or break a career. The prestige associated with such articles can trump many things. Having such publications can open many doors in terms of jobs, grants, tenure, invited talks and more. Indeed last week in Nature, articles were written about just this phenomenon, the so called "golden club". Not surprisingly most of the traditional journals with such cachet are subscription based, although there are at least two open access journals that are certainly up there (PLoS Biology and ELife).

Since most of the prestigious journals are subscriptions based, and there are such strong incentives to publish in them, it makes it very difficult for many researcher to move to publishing in open access journals (although they can still submit papers to institutional or disciplinary repositories). If I had the opportunity to publish in Nature or Science, would I? Yes, precisely because I know that having such a publication will open doors, aid in getting grants, promotions and raises. While I feel strong support for open access, I am frankly not above such concerns. Some of this may simply reflect my petty needs for external validation of my science (which I can get over), but grants and raises potentially influences the quality of my life and my work. It is hard to pass that up.

Perceptions of open access journals

There remains a common misperception that many open access journals are nothing more than predatory or "vanity" publications with little or no rigorous peer review. A recent "sting" by the science journalist John Bohannon in Science has done little to help this perception. Too much has already been written about this article, mostly highly critical of his methods, biased sampling approach and lack of a control group. While It was presented as a news piece (not a scholarly article), Bohannon  has stated on several occasions that his original plan was to submit this to PLoS One (an open access article with peer review) so this remains an issue.

As Peter Suber (among many others) describes in his book there are currently two models of open access. The first (so called green OA) means that while papers may be published in subscription based journals, a free version of the accepted manuscript (usually without final copyediting and typesetting provided by the journal) is placed in a repository such as pubmed central or an institutional archive. Often this "free" version has a 6-12 month delay before being released. Since this model of green OA is a required stipulation for projects funded by organizations such as the NIH, some journals (where the majority of authors are funded by such agencies) are now just making all of their content open access after a 12 month embargo).

The other major model for open access publishing is gold open access. In this case, once  a manuscript has gone through peer review by expert referees and academic editors, and it is accepted, then the authors of the manuscript are charged a fee for typesetting and (usually online) publication.  Thus the model is that the authors, not the readers are charged. In the life sciences the funds for this usually (more on this in a second) come from granting agencies, although many journals have fee waivers (or no fees at all).

The concern with this of course is this may create a perverse incentive system, such that journals would increase their acceptance rate to increase profit (~1-2K/paper accepted). Thus the rigor of peer review could be negatively impacted, resulting in so called "vanity publications" that have the veneer of scientific rigor and peer review, but in fact do not. Couple this with so called predatory (scam) journals (that are much like other scam spam).  Before open access journals existed, such vanity journals already existed among the subscription models. And as the Bohannon sting has shown us, journals that are published by well known publishers like Elsevier, are not above being "stung" and by accepting faux articles with obviously flawed methodologies as well. Beyond that, somewhere on the order of 70% of all open access journals have no author side fees.


Despite this issue, and the existence of predatory and possible vanity journals (such as many of those found on Beall's list), the Open access scholarly publishers association has a code of conduct for journals aiming to maintain reputable scholarly journals from predatory ones. From my perspective, the journal PLoS One which in many ways represents the flagship of open access journals (peer review entirely based upon technical soundness of the experiments and interpretation, not upon subjective assessment of novelty) was noted for how thorough the review process (and rejection was). The other worth while point is to take a look at the re-analysis done by Brian Wood. Seems like the one thing that journal impact factor might be useful at doing is predicting whether a reasonable amount of peer review might take place.

It is also worth pointing out that problems with sufficient peer review occurs with subscription based journals as well. In addition there has been a history of these so called vanity journals even among subscription publishers. In addition, many journals with subscription based models also have page and figure charges that the authors must pay, so some of the same incentives also apply to these journals. In my own personal experience, these page charges end up being about the same cost as publication in open access journals. So many of the same charges against OA journals can equally be leveled against such journals.

Why have I not embraced open access completely?

It is probably clear from my perspective on all of this, that I am firmly in favour of open access models of publishing, and like I stated from the outset, I do think that this is where everything is going to, although by what model I am not sure.

 So given all of this, why don't I publish exclusively in open access journals? Well there are two reasons, or possibly one reason arising from two different parts of my mind.

The first relates to "establishment" journals. In my field, there are several well regarded journals that have persisted for a very long time, some for over a century such as Genetics. In my field, publishing my work in journals such as Genetics, or in Evolution means that A) It has a natural readership. B) These are the same journals that shaped my understanding of the field during my intellectual development and so I have a fondness for them and C) While they may not have the cachet of Nature, Science and the like.. there is no doubt that in my field they are considered well regarded journals. D) These also represent the journals for my professional societies, which I actively support and promote above and beyond their role in scholarly communication.

As for the second set of reasons.. I am not sure I am willing to be a martyr. In other words, I may be acting with a great deal of cowardice. Despite having been an editor at PLoS One for many years, and I stand by the rigor of reviews by my referees and myself, there is no doubt that there are many in the community who still believe that it (as a journal) accept anything. If I choose to publish all of my work (and that of my students and postdocs), I risk losing readership. If such views are held by university administrators I risk loss of salary raises promotions and grants (depending on the panel).

Thus until the incentive system has changed, and this can only change by concerted effort between university administrations, grant program officers and well established scholars in each of our fields embracing such changes, many researchers like myself will continue using this screwed up system, because of the incentives, risking further erosion of public trust.  Is my half way attitude a cop-out. Yes. Some horrible mix of rationalization, cowardice and avarice I suppose. Am I likely to change my behaviour? Probably not until my mortgage is paid off and my kids have finished university.


Tuesday, October 22, 2013

How easy should it be to replicate scientific experiments?

The economist just published a pair of articles broadly about the state of affairs in scientific research (and from their perspective everything is in a tail spin). "How Science Goes Wrong" and " Trouble at the lab". Both articles are worth reading, although few will find themselves in agreement with all of their conclusions. Neither article takes very long to read, so I will not try to sum up all of the arguments here.  For two very different perspectives on these articles check out Jerry Coyne's blog who largely agrees with the statements they make. An alternative perspective on why these articles missed the mark almost entirely, see the post by Chris Waters my colleague here at Michigan State University . Chris points out that most studies do not represent a single experiment examining a particular hypothesis, but several independent lines of evidence pointing in a similar direction (or at least excluding other possibilities).

 However, instead of going through all of the various arguments that have been made, I want to point out some (I think) overlooked issues about replication of scientific experiments. Principally that it can be hard, and even under extremely similar circumstances stochastic effects (sampling) may alter the results, at least somewhat.

Let's start by assuming that the original results are "valid", at least in the sense that there was no malfeasance (no results were faked), the experiments were done reasonably well (i.e. those performing the experiments did them well with appropriate controls), and that the results from the experiments were not subject to "spin" and no crucial data was left out of the paper (that may negate the results of the experiments). In other words, ideally what we hope to see out of scientists.

Now, I try and replicate the experiments. Maybe I believe strongly in the old adage "trust but verify" (in other words be a skeptical midwesterner). Perhaps, the experimental methods or results seem like a crucial place to begin for a new line of research (or as an alternative approach to answering questions that I am interested in).

So, I diligently read the methods of the paper summarizing the experiment (over and over and over again), get all of the components I need for the experiment, follow it as best as possible, and .... I find I can not replicate the results. What happened? Instead of immediately assuming the worst from the authors of the manuscript, perhaps consider some of the following as well.

1- Description of methodological detail in initial study is incomplete (this has been and remains a common issue). Replication is based on faulty assumptions introduced into the experiment because of missing information in the paper. Frankly this is the norm in the scientific literature, and it is hardly a new thing. Whether I read papers from the 1940's, 1970's or from the present I generally find the materials and methods section lacking, from the perspective of replication. While this should be an easy fix in this day and age (extended materials and methods included as supplementary materials or with the data itself when it is archived), it rarely is.

What should you do? Contact the authors! Get them on the phone. Often email is a good start, but a phone or skype call can be incredibly useful at getting all of the details out of those who did the experiment. Many researchers will also invite you to come spend time at their lab to try out the experiment under the conditions, which can really help. It also (in my mind) suggests that they are trying to be completely above board and feel confident about their experimental methods, and likely their results as well. If they are not willing to communicate with you about their experimental methods (or to share data, or how they performed their analysis), you will probably be in good shape to feel skeptical about how they have done their work.

2- Death by a thousand cuts. One important issue (relating to the above) is that it is almost impossible to perfectly replicate an experiment, ingredient for ingredient (what we call reagents). Maybe the authors used a particular enzyme. So you go ahead and order that enzyme, but it turns out to be from a different batch, and the company has changed the preservative used in the solution. Now, all of a sudden the results stop working. Maybe the enzyme itself is slightly different (in particular if you order it from a different company).

 If you are using a model organism like a fruit fly, maybe the control (wild type) strain you have used is slightly different than the one from the original study. Indeed, in the post by Jerry Coyne mentioned above, he discusses three situations where he attempted to replicate other findings and failed to do so. However, in at least two of the cases I know about, it turned out that there were substantial differences in the wild type strains of flies used. Interesting arguments ensued, and for a brief summary of it, check out box 2 in this paper. I highly recommend reading the attempts at replication by Jerry Coyne and colleagues, and responses (and additional experiments) by the authors of the original papers (in particular for the role of the tan gene in fruit fly pigmentation).

Assuming that the original results are valid, but you can not replicate them, does it invalidate the totality of the results? Not necessarily. However, it may well make the results far less generalizable, which is important to know and is an important part of the scientific process.

3- Sampling effects. Even if you follow the experimental protocol as closely as possible, with all of the same ingredients and strains of organisms (or cell types, or whatever you might be using), you may still find somewhat different results. Why? Stochasticity. Most scientists take at least some rudimentary courses in statistics, and one of the first topics they learn about is sampling. If you have a relatively small number of independent samples that you use (a few fruit flies for your experimental group, compared to a small number in their control group), there is likely to be a lot of stochasticity in your results because of sampling. Thankfully we have tools to quantify aspects of the uncertainty associated with this (in particular standard errors and confidence intervals). However for many studies they treat large quantitative differences as if they were essentially discrete (compound A turns transcription of gene X off....).  Even if the effects are large, repeating the experiment again may result in somewhat different results (different estimate, even if confidence intervals overlap).

If the way you assess "replication" is something like "compound A significantly reduced expression of gene X in the first experiment, does it also significantly reduce expression upon replication", then you may be doomed to frequently failing to replicate results. Indeed statistical significance (based on p values etc...) is a very poor tool in statistics. Instead you can ask whether the effect is in the same direction, and whether the confidence intervals between the initial estimate and the new estimate upon replication overlap.

Ask the authors of the original study for their data (if it is not already available on a data repository), so you can compute the appropriate estimates, and compare them to yours. How large was their sample size? How about yours? Can that explain the differences?

4- Finally, make sure you have done a careful job at replicating the initial experiment itself. I have seen a number of instances where it was not the initial results, but the replication itself which was suspect.

Are there problems with replication in scientific studies? Yes. Are some of the due to the types of problems as discussed in the economist or on retraction watch? Of course. However, it is worth keeping in mind how hard it is to replicate findings, and this is one of the major reasons I think meta-analyses are so important. It also makes it clear why ALL scientists need to make their data available through disciplinary or data type specific repositories like DRYAD, NCBI GEO, the short read archive or more general ones like figshare.





Monday, October 14, 2013

Fallout from John Bohannon's "Who's afraid of peer review"

As many many scientists, librarians and concerned folk who are interested in scientific publishing and the state of peer review are aware, the whole 'verse' was talking about the "news feature" in Science by John Bohannon entitled "Who's afraid of peer review?".

The basics of the article was a year long "sting" operation on a "select" group of journals (that happened to be open access.. more on this in a second) focusing in part on predatory/vanity journals. That is some of the journals had the "air" of a real science journal, but in fact would publish the paper (?any paper?) for a fee. Basically Bohannon generated a set of faux scientific articles that at a first (and superficial) glance appeared to represent a serious study, but upon even modest examination it would be clear to the reader (i.e. reviewers and editors for the journal) that the experimental methodology was so deeply flawed that the results were essentially meaningless.

Bohannon reported that a large number of the journals he submitted to accepted this article, clearly demonstrating insufficient (or non-existent peer review). This and the head line has apparently lead to a large amount of popular press, and many interviews (I only managed to catch the NPR one I am afraid).

 However, this sting immediately generated a great deal of criticism both for the way it was carried out, and more importantly the way the results were interpreted. First and foremost (to many) that ALL of the journals that were used were open access, and thus no control group for journals with the "traditional" subscription based models (where libraries pay for subscription to the journals). In addition, the journals were sieved to over-represent the shadiest predatory journals. That is it did not represent a random sample of open access journals. One thing that really pissed many people off (in particular among advocated of open access journals, but even beyond this group) that Science (A very traditional subscription based journal) used the summary headline: "A spoof paper concocted by Science reveals little or no scrutiny at many open-access journals.", clearly implying that there was something fundamentally wrong with open access journals. There are a large number of really useful critiques of the article by Bohannon including ones by Michael Eisen, The Martinez-Arias lab, Lenny Teytelman, Peter Suber, Adam Gunn (including a list of other blogs and comments about it at the end). There is another list of responses found here as well.  Several folks also suggested that some open access advocates were getting overly upset, as the sting was meant to focus on just the predatory journals. Read the summary line from the article highlighted in italics above, as well as the article and decide for yourself. I also suggest looking at some of the comment threads as Bohannon does join in on the comments Suber's post, and many of the "big" players are in on the discussion.

A number of folks (including myself) were also very frustrated with how Science (the magazine) presented this (and not just for the summary line). Making the "sting" appear to be scientifically rigorous in its methods, but then turning around and saying this is just a "news" piece whenever any methodological criticism is discussed. For instance, when readers commented about both the lack of peer review and the biased sampling of journals used for the "sting" operation for Bohannon's article, this was a response by John Travis (managing editor of News for Science magazine):



I was most interested in the fact Science (the journal) had an online panel consisting of Bohannon, Eisen and David Roos (as well as Jon Cohen Moderating) to discuss these issues. Much of it (especially in the first half hour) is worth watching, I think it is important to point out that Bohannon suggests he did not realize how his use of only OA journals as part of the sting operation would be viewed. He suggests that he meant this as largely a sting of the predatory journals, and that if he did it again he would have included the subscription based journals as a control group. You can watch it and decide for yourself.

The panelists also brought up two other important points that seem to not get discussed as much in the context of open access vs. subscription models for paying for publication or for peer review.

First, many subscription based journals (including Science) have page charges and/or figure charges that the author of the manuscript pays to the journals. As discussed among the panelists (and I have personal experience with paying for publication of my own research), these tend to be in the same ballpark as for the publication of open access papers. Thus the "charge" that the financial model for publication for OA journals would lead to more papers being accepted is true for many of the subscription journals as well (in particular for journals that are entirely online).

Second (and the useful point to come out of Bohannon's piece) is that there are clear problems with peer review being done sufficiently well. One suggestion that was made by both Eisen and Roos (and has been suggested many times before) is that the reviews provided by the peer referees of the manuscript and the editor could be published alongside (or as supplemental data on figshare) the accepted manuscript, so that all interested readers can assess the extent to which peer review was conducted. Indeed there are a few journals which already do this such as PeerJ, Embo J, ELife, F1000 Research, Biology Direct and some other BMC-series (see here for an interesting example), Molecular Systems Biology, Copernicus Journals. Thanks to folks on twitter for helping me put together this list!

 This latter point (providing the reviews alongside published papers) seems to be so trivial to accomplish, and the reviewers names could easily remain anonymous (or they could provide their names providing a degree of academic credit and credibility to the scientific community) if so desired. So why has this not happened for all scientific journals?  I am quite curious about whether there are any reasons NOT to provide such reviews?

Friday, September 13, 2013

Learning something new: Integrating computer vision into my research.

I recently started my sabbatical year, where I get a chance to re-tool myself, and my research knowledge. The game plan is to learn how to integrate computer vision (machine vision) and machine learning approaches into my research, in particular with respect to the study of animal behaviour and the analysis of images (and videos). We study the evolutionary genetics of complex phenotypes in my lab. While this used to (mostly) mean the complex structure of the shape and size of fruit-fly wings, we are moving more into the study of animal behavior. In particular how flies evade and escape being eaten by predators (more on that at a later date).

 The analysis of such data (both huge sets of wing images as well as video, which is effectively a series of images) can be time consuming and what can be done manually is somewhat limited (such as with JWatcher), in particular if you want to do "high throughput" work with many samples. I have over the past few years interacted, and begun to collaborate with scientists who are using all sorts of techniques from computer vision which have amazed me, both with respect to the speed of the analysis, but also the detailed information gleaned from such approaches. So I am trying to get up to speed and see how to utilize these approaches for my own work.

 To that end I will be now posting about this experience (as well as all of the more usual genetics). This will include useful new tidbits, programming scripts, software I have tried (and tutorials), books, and anything else I can think of. Basically my research progress journal for this new endeavour. I hope that this will help me stay nice and organized, and perhaps will be useful more generally. If you start to follow this thread, and have suggestions for anything, please let me know in the comments or on twitter.

More to follow soon!

Our new pre-print: An integrative genomic approach illuminates the causes and consequences of genetic background effects

This is a guest post by Dr. Chris Chandler. Cross posted from Haldane's Sieve.

Biologists have long recognized that a mutation can have variable effects on an organism's phenotype; even introductory genetics classes often make this observation by introducing the concepts of penetrance and expressivity. More mysterious, however, are the factors that influence the phenotypic expression of a mutation or allele. We know, for instance, that introducing the same mutation into two different but otherwise wild-type genetic backgrounds can result in vastly different phenotypes. But what specific differences between these two genetic backgrounds interact with the mutation, and how? And how does gene expression fit into this puzzle? Answering these questions has not been an easy task, which is not too surprising when you realize that penetrance and expressivity are, in reality, complex quantitative traits. We therefore adopted a multi-pronged genetic and genomic approach to tease apart the mechanisms mediating background dependence in a mutation affecting wing development in the fly Drosophila melanogaster.

The phenotypic patterns seen in our model trait have already been characterized: the scalloped[E3] (sd[E3]) mutation has strong effects in the Oregon-R (ORE) background, resulting in a tiny, underdeveloped wing, while its effects in the Samarkand (SAM) background are still obvious but much less extreme, resulting in a blade-like wing.

To try to find out what causes these differences, we generated and combined a variety of datasets: whole-genome re-sequencing of the parental strains and a panel of introgression lines to map the background modifiers of the sd[E3] phenotype; transcription profiling (using two microarray datasets and one RNA-seq-like dataset), including analyses of allele-specific expression in flies carrying a "hybrid" genetic background; predictions of binding sites for the SD protein, which is a transcription factor; and a screen for deletion alleles that enhance or suppress the sd[E3] phenotype in a background-dependent fashion.

Our results point to a complex genetic basis for this background dependence. We found evidence for a number of loci that are likely to modulate the effects of the sd[E3] allele. However, some unexpected inconsistencies provide a cautionary tale for those intending to take a similar mapping-by-introgression approach for their trait of interest: do multiple replicates, and introgress in both directions, or you may inadvertently end up mapping some other trait! Although the number of candidate genes we identified were generally large, by combining those results with data from our other datasets, we were able to narrow our focus to those showing a consistent signal, yielding a robust set of candidate genes for further study. Without getting into too much detail, we also used a novel approach to show that background-dependent modifier deletions of the sd[E3] phenotype (of which there are many) involve higher-order epistatic interactions between the sd[E3] mutation, the deletion, and the genetic background, rather than quantitative non-complementation (so more than two genes were involved).

Overall, we think that an integrative approach like this could be useful for others trying to understand complex traits, including genetic background-dependence of mutations. In addition, if you're a Drosophila researcher working with the commonly used Samarkand or Oregon-R strains, our genome re-sequencing data (raw and assembled), including SNPs, will soon be available in public repositories for genetic data.


Wednesday, July 31, 2013

Evolution and Core Processes in Gene Regulation – some “terminal” thoughts (guest post from David Arnosti)

Guest appearance by David Arnosti here; I’m Ian’s colleague at Michigan State University and co-organizer for the ASBMB Special Symposium.

Our symposium last week brought together some folks who don’t regularly appear at the same conferences, including the structural biologists and biochemists who’ve devoted a good part of the last 30 years to unraveling the mechanisms of the central dogma – gene transcription, RNA metabolism, and protein translation. The trend has been to identify the central machinery, publish high-impact papers in single-word-title journals, and then years later discover that things don’t necessarily work the same in all contexts, organisms, developmental settings. Not surprising in eukaryotic transcription, for instance, where the “basal machinery” comprises ~200 proteins. Zach Burton, conference participant, refers to this complexity as a “molecular horror”, but from an evolutionary perspective, it is also an opportunity.

With respect to tracking the changes inherent in functioning of regulatory circuitry, we have more complete understanding of how bacterial systems work. Nice presentations by Saeed Tavazoie and Eduardo Groisman highlighted how easily such systems can transition between regulatory states, with just a few genetic changes in regulatory factors. Robert Landick and Seth Darst, in studies of E. coli RNA polymerase, pointed out that this bacterium actually features a novel outgrowth, an insertion of 188 amino acids that connects directly to the conserved trigger loop in the catalytic site. Nobody knows what it is doing there, but it is lineage specific, and mutations accumulate in this part of the protein when cells are grown under nutrient limitation, suggesting a short-circuit way to globally fiddle with gene expression.

Eukaryotic systems likewise have novel structures to their core machinery; Lawrence Myers described the gene amplification of Mediator subunits in Candida albicans that are linked to pathogenicity, while Jean-Marc Egly pointed out the pervasive effects of mutations in human Mediator and transcription factor TFIIH. With eukaryotes, the importance of variability in core machinery for generating important changes on the population or species level is obscure. Studies such as those presented by Ian Dworkin (host of this blog) and Aviv Regev showed how we are able to identify numerous loci involved in genetic background effects relating to development and immune function – but the overall importance of pervasive impacts generated by changes in an RNA polymerase subunit, for instance, vs. subtle changes in an enhancer is not clear. One mystery I dropped on the conferees was the special features of the RNA Pol II CTD found in Drosophila, but not other eukaryotes – a reflection of their unique developmental gene expression, discussed by Melissa Harrison and Julia Zeitlinger?

Aside from being mistaken once for Bill Gates by a visitor from Shanghai while walking around the University of Chicago, I was able to maintain my identity as a gene regulation specialist who takes to heart Theodosius Dobzhansky’s mantra that “Nothing in Biology Makes Sense Except in the Light of Evolution”. We will see how the combination of biochemical detail and evolutionary perspective can propel us into a future where gene regulation, in all its rich variation, makes sense. Many thanks to Joan Geiling and Barbara Gordon from the ASBMB for making this an outstanding conference!