Monday, April 15, 2013

Ecology goes east: research in China


It is increasingly common to see papers from Chinese institutes in top ecological journals, and Chinese ecological research is growing exponentially. I've been chatting informally about the topic of Chinese ecology with Shaopeng Li, who is a graduate student visiting the Cadotte lab from Sun Yat-sen University in China. His thoughts about where Chinese ecology is going and about being a graduate student in ecology there were so interesting that I talked him into letting me post some of his answers. As you might expect, some things are the common everywhere - grad students have low wage and work long hours, supervisors can be intimidating - and some things are distinctly different - for example, hiring armies of farmers to help with fieldwork. Of course this reflects Shaopeng's experience and thoughts,  and others who have had similar or different experiences there are encouraged to comment.

To start with, what is the general perception of ecology in China? Is it popular as a science? How likely are undergrads to choose it as a major or postgraduate degree?
Shaopeng Li: The common people in China often treat ecology as “ecological civilization”, “environmental protection” or “sustainable development”. Few people recognize it as a science. Some people even don’t know the difference between ecologists and environmentalists. But I think most people agree that ecology and what the ecologists do are very important to the development of China and their own life, despite that they often do not know what the ecologists exactly do.

It is sad to say that ecology is one of the most unpopular areas of life sciences in China. Most of undergrads in life sciences want to get a Master or PhD degree in molecular biology, pharmacy or environmental technology, which is easier to find a suitable job. Undergraduate students who major in ecology find it hard to get jobs in China. Most of them now think about career change. But we believe the situation will change in next five years.

How well are ecology grad students paid? What are the hours like? What are your regular duties? (i.e. do you teach, do field work, write papers? etc).
SL: The pay of the students in all the universities of China is very low. For example, in our school, the PhD students could get 1,500 RMB/month [~$250 USD], and the master students could only get 600-800 RMB/month. But the students of Chinese Academy of Sciences could get much more.

In China, most of the graduate students work very hard, from 9:00 am to 5:30 pm in every workday. Sometimes we must work extra hours at night or weekend. I know some of my friends often sleep in their work office. But it depends on the culture of different labs. In my lab, if you could finish your duties on time, you could set your own hours.

Students in my lab do not need to teach, although other students may have to. As a TA, we only need to send messages to the undergrads. Most of a PhD’s time is spend on fieldwork, experiments and paper-writing. Master students do not need to publish papers, so they spend most of their time on doing experiments in the first two years. For the third year, they will spend their time on thesis and finding jobs.

How are research labs structured?
SL: In the labs of our department (School of Life Sciences), we often have one professor (the PI), two or three associate professors, three or four postdoctorates, ten PhD students and 20 master students. We often do not have assistant professors in universities, and it is much easier to become an associate professor in China than in Western countries. Our lab is a little smaller than average; we only have 20 people. Some labs of the famous molecular biologists often have more than 40 students. The biggest lab in our school has about 100 master and PhD students total.

What is your perception of differences between the lab here and the lab you came from?
SL: In China, one big lab often focuses on many different projects. Take our lab for example, we have three different research areas: phytoremediation, environmental microbiology and biodiversity and ecosystem function. The biggest problem is that nobody could understand your research fully except yourself, even your supervisor. If you have any technological or statistical question, you must search for the books or papers by yourself, and it often takes us a lot of time to find the suitable methods and learn how to use them. But in lab here, many of us focus on phylogenetic ecology. If I have any problem, I could discuss it with Marc, you and Lanna [another graduate student] directly. It saved me a lot of time and I can pay more attention to the scientific question, not the technology.

Another difference is the relationship between the students and the professors. In China, the supervisor plays a role as a father, sometimes he is very kindly and sometimes he is very critical. Most of students are afraid of their supervisors. But here, we are all friends and the lab is like a big family. [CT-This may vary among western labs...] One noticeable phenomenon is that there are more excellent female ecologists in western countries. In China, it is very stressful for a girl to become a PhD student because of the traditional culture, especially in ecology.

Are English-language journals available to students? When you publish, is it in Chinese journals, English journals, or a mixture? Is it considered better to publish in international journals?
SL: Most of the English journals are available in Sun Yat-sen University. I think it is not a problem for the top 50 universities in China. However, for small universities and colleges, it may be very difficult for them to download English papers.

Most of the professors do not encourage students to publish papers in Chinese journals. If you only publish papers on Chinese journals, you will not get a good position after you graduate. Instead, publishing papers in international journals is very important for our academic career. If anyone could publish one research paper in Science or Nature, he may be able to get an associate professor position in any universities in China, even full professor position in some universities. However, some of the famous Chinese ecologists publish review papers in Chinese journals to introduce recent international advances, which is a good thing for our young students.

What are the requirements for finishing your PhD? How long will it usually take?
SL: Every student needs to publish at least one paper in any international journals listed on the Web of Knowledge to get their PhD degree. In some departments of our university, you must publish a paper in top journals with an impact factor higher than 3 or 5. We also need to write a thesis and pass the defence. But the thesis is not as important as the paper. I have never seen anyone who published a SCI paper cannot pass the defence. It takes us about 5 years totally to get a PhD degree. If you already have a master’s degree, it only takes you three years. But if you cannot publish a SCI paper on time, you can only get the degree after your paper is accepted. Half of PhD students in our department could not get their degree on time. Most of them would spend one or two years more to wait for the final acceptance for the paper (This is why Chinese scientists often want to urge the editors to deal with their papers as soon as possible). If you cannot publish any paper in your seventh year, you cannot get your degree anymore.

How important is mathematics in ecology in China? Are students expected to have a strong background in it?
SL: All Chinese students have a strong background in mathematics, except for statistics. I think the weak background in statistics is the second biggest problem for ecology students in China (The first one is English). Most of us have not learned statistics comprehensively. If we want to learn some methods of advanced biometrics, we need to read the obscure statistics books. Then we still cannot understand quite well. Most of our students want to learn more about statistics. Last year, Prof. Fangliang He, then at University of Alberta, ran a course named Advanced Biometrics in our university. More than 50 PhD students from 10 different universities came to our university to take this class. Few professors and students focus on theoretical ecology. Instead, most students want to know some advanced skills to deal with their experimental data.

What is doing fieldwork in China like?
In my opinion, we do much more fieldwork than the students of North American universities. I have spent most of my time on grassland experiments and fixed plots experiments in natural reserves. Sometime we even live in a tent on the top of the mountain for several days to collect specimens. The fieldwork in China is often very heavy. I also know that one PhD student who built up 100 fixed plots all over the China by herself.

For most of the time, if it is available, we often hire a lot of laborers to help us do the fieldwork. Chinese farmers are very kind and professional. They do the fieldwork much better than our students. Hiring laborers is very cheap in China, and this is why we could do a lot of big projects that the western ecologists may not be able do.
A large-scale biodiversity and ecosystem function experiment. The people in the picture are hired labourers who do the fieldwork.
http://www.bef-china.de/index.php/en/
What do you think is behind the recent growth in Chinese science in general, and ecology in particular?
SL: Recently, the development of science in China is very fast, with more and more Chinese scientists publishing high impact papers in international journals. I think there are many reasons. First, Chinese government is paying more and more attentions and money to scientific research, especially the hot topics such as climatic change, biological invasion and environmental pollution. The total investment of research funds was approximately one trillion in 2012 in China. Second, we have the largest number of researchers and PhD students all over the world. The number is still increased very quickly. Third, more and more ethnic Chinese (even non-ethnic Chinese) scientists would like to come back to work in China, which greatly narrowed the gap of research capabilities between China and western countries. In the area of ecology, the international communication and the ethnic Chinese ecologists in western countries contribute a lot to the development of ecology in China. More and more Chinese scientists want to interact with western ecologists. And 80% of the papers published by Chinese have foreign co-authors, who often help them to improve the language and statistical analysis.

However, there are still many problems in our science research. In my opinion, the lack of creative and critical thinking is the biggest problem in recent Chinese science. Most of the time, we are just following the hot topics. For ecology, there are few new theories or hypothesis created by Chinese ecologists. Instead, we like to do a lot of work on long-term and large scales experiments to test the recent hot topics. We spend more money and labor force on research projects, but often publish papers of lower qualities. There are many big project at large scales in China. For example, we have about 15 plots in the Center for Tropical Forest Science (CTFS) system, each 5-30ha. The Chinese Ecosystem Research Network (CERN) also consists of 36 field research stations all over the nation. Few Chinese ecologists focus on theoretical ecology and ecological modeling. Personally, I want to see more work with a basis in well-defined hypothesis and clever experiment design.

Are the ecological topics that are popular in China similar to those that are popular in North America? Is there more or less of a focus on ecological applications, or is basic research also very common there?
SL: I think the three most popular ecological topics in China are: climatic change, biological invasion and the causes and consequences of biodiversity. Most of us focus on the hot topics that are popular in North America (also easy to publish papers in good journals). Our discipline is not comprehensive as North America. Many of the traditional sciences such as taxonomy are dying out.

A lot of ecologists focus on ecological applications in China. Environmental Engineering, restoration ecology and phytoremediation are always hot topics in China because of the serious environmental problems. The ecologists focusing on applications are more popular in newspapers and TV. But doing basic research often has more academic influence.

What is the government doing to encourage scientists to stay in China or come back to China from overseas?
SL: The Chinese government has done a lot of things to encourage oversea scientists come back to China. For example, in December, 2008, the General Office of the Central Committee of the Chinese Communist Party made a decision to have high-level talents (full professor) from overseas come to work in China. Every one could get a lump-sum subsidy of 1 million RMB [~$160,000 USD] and a research subsidy ranging from 3 to 5 million RMB [~$0.5 million USD]. They proposed the “1000-talent Plan”. There are a total of 2,263 registered by July 2012. They also have sub-programs for the young researchers (postdoctorate and assistant professor) and non-ethnic Chinese experts. These subsidies are much higher than the income of native professors. There are many policies that favor scientists from overseas. Advertised positions of Chinese universities often ask for overseas research experiences and papers on top journals.

In contrast, the life of young scientists who stay in China seems very miserable. The subsidies for PhD students, post-doctorates and associate professors are much much less, although they can vary.  More importantly, you could not find a good position because you do not have “overseas research experiences” and high-quality papers. This is why more and more young people in China want to study abroad. The government does also encourages young scientists to study abroad. Every year, China Scholarship Council (CSC) supports more than 10,000 students to study abroad as full or visiting PhD students. For example, I am a visiting PhD supported by CSC, and my scholarship covers all the international airfare and my living stipend in Canada for one year. 
Students from Shaopeng's lab in the field. Shaopeng is second from the right.


Edited 4:00 pm EST, April 15 2013.

Thursday, April 11, 2013

Navigating the complexities of authorship: Part 1 –inclusion


One of the highlights of grad school is publishing your very first papers in peer-reviewed journals. I can still remember the feeling of seeing my first paper appear in print (yes on paper and not a pdf). But what this novice scientist should not be fretting over is which colleagues should be included as authors and whether they are breaking any norms. The two things that should be avoided are including as authors, those that did not substantially contribute to the work, and excluding those that deserve authorship. There have been controversial instances where breaking these authorship rules caused uncomfortable situations. None of us would want someone writing a letter to a journal arguing that they deserved authorship. Nor is it comfortable to see someone squirming out of authorship, arguing they had minimal involvement when an accusation of fraud has been levelled against a paper. How to determine who should be an author can be difficult.






Even though I spell out my own rules below, it is important to be flexible and to understand that different types of papers and differing situations can have an impact on this decision. That said, you do not want to be arbitrary in this decision. For example, if two people contribute similar amounts to a paper, you do not want to include only one because you personally dislike the other. You should have a benchmark for inclusion that can be defended. The cartoon above highlights the complexity and arbitrariness of authorship –and the perception that there are many instances of less than meritorious inclusion.

Journals do have their own guidelines, and many now require statements about contributions, but even these can be vague, still making it difficult to assess how much individuals actually contributed. When I discuss issues of authorship with my own students, I usually reiterate the criteria from Weltzin et al. (2006). I use four criteria to evaluate contribution:
1)   Origination of the idea for the study. This would include the motivation for the study, developing the hypotheses and coming up with a plan to test hypotheses.
2)   Running the experiment or data collection. This is where the blood, sweat and tears come in.
3)   Analyzing the data. Basically moving from a database to results, including deciding on the best analyses, programming (or using software) and dealing with inevitable complexities, issues and problems.
4)   Writing the paper. Putting everything together can sometimes be the most difficult and external motivation can be important.

My basic requirements for authorship are that one of these steps was not possible without a key person, or else there was a person who significantly contributed to more than one of these. Such requirements mean that undergraduates assisting with data collection do not meet the threshold for authorship. Obviously these are idealized and different types of studies (e.g., theory or methodological papers) do not necessarily have all these activities. Regardless, authors must have contributed in a meaningful way to the production of this research and should be able to defend it. All authors need to sign off on the final product.

While this system is idealized, there are still complexities making authorship decisions difficult or uncomfortable. Here are three obvious ones –but there are others.

Data sharing
Large, synthetic analyses require multiple datasets and some authors are loath to share their hard work without credit. This is understandable, as a particular dataset could be the product of years of work. But when is inclusion for authorship appropriate? It is certainly appropriate to offer authorship if the questions being asked in the synthesis overlap strongly with planned analyses for the dataset. Both the data owner and the synthesis architect have a mutual interest in fostering collaboration. In this case every effort should be made to include the data owner in the analyses and writing of the manuscript.

When is it not appropriate to include data owners as authors? First and foremost, if the data is publically available, then it is there for further independent investigation. No one would offer authorship to each originator of a gene sequence in Genbank. Secondly, if it is a dataset that has already been used in many publications and has fulfilled its intended goals, then it should be made available without authorship strings. I’ve personally seen scientists reserve the right of authorship for the use of datasets that are both publically available and have satisfied the intended purpose long ago.

The basic rule of thumb should be that if the dataset is recent and still being analyzed, and if the owner has an interest in examining similar questions, then authorship should be offered –with the caveat that additional work is required, beyond simply supplying the data.

Idea ontogeny
I thought about labeling this section ‘idea stealing’ but thought that wasn’t quite right. An idea is a complex entity. It lives, dies and morphs. It is fully conceivable to listen to a news story about agricultural subsidies, which somehow spurs an idea about ecosystem dynamics. We all have conversations with colleagues and go to talks, and these interactions can morph into new scientific ideas, even subconsciously. We need to be careful and acknowledge how much an idea came from a direct conservation with another scientist. Obviously if a scientist says “you should do this experiment…”,  then you need to acknowledge them and perhaps turn your idea into a collaboration.

Funding
Now here is the tricky one. Often people are authors because they control the purse strings. Yes, a PI has done an excellent job of securing funding, and should be acknowledged for this. If the study is a part of a funded project, where the PI developed the original idea, then the PI fully deserves to be included. However, if the specific study is independent from the funded project in terms of ideas and work plan, but uses funding from this project, then this contribution belongs in the acknowledgements and does not deserve authorship. There are cases where the PI of an extremely large lab gets dozens of papers a year, always appearing last in the list of authors (see part 2 on author order -forthcoming), and it is legitimate to view their contributions skeptically. Their relationship to many of the papers is likely financial and they probably couldn’t defend the science. I had a non-ecologist colleague ask me if it was still the case that graduate students in ecology produce papers without their advisors, to which I said yes (Caroline has several papers without me as an author).

Clearly there are cultural differences among sub disciplines. However, I do feel that authorship norms need to be robust and enforced. Cheaters (those gratuitously appearing on numerous papers –see part 3 on assigning credit; also forthcoming) reap the rewards and benefits of authorship, with little cost. It is disingenuous to list authors that have not have a substantial input into the publication, and the lead author is responsible for the accuracy of authorship. The easiest way to ensure that authors are really authors is to make an effort to include them in various aspects of the paper. For example, give them every opportunity to provide feedback –send them the first results and early drafts, have Skype for phone meetings with them to get their input and incorporate that input. Ultimately, we all should walk away from a collaboration feeling like we have contributed and made the paper better, and we should be proud to talk about it to other colleagues.


Many of these ideas were directly informed by this great paper by Weltzin and colleagues (2006):

Weltzin, J. F., Belote, R. T., Williams, L. T., Keller, J. K. & Engel, E. C. (2006) Authorship in ecology: attribution, accountability, and responsibility. Frontiers in Ecology and the Environment, 4, 435-441.

http://www.esajournals.org/doi/abs/10.1890/1540-9295(2006)4%5B435:AIEAAA%5D2.0.CO%3B2 

Friday, April 5, 2013

Measuring the Pacific extinction spasm


ResearchBlogging.orgIt is a fact that humans have caused numerous extinctions around the globe. Almost all of the large bodied mammals of North America disappeared after the arrival of humans sometime around 20,000 years ago –likely due to compounding effects of hunting and climate change.  This North American example has been controversial, largely because it constitutes a single observation. However, humans colonized the Pacific islands over a span of a couple of thousand years, between 3,500 to 700 years ago. Species extinctions followed these colonizations on each island, confirming the link between humans and extinctions. Yet how many species went extinct? This question may be relatively easily answered for large organisms since evidence of their existence is well recorded, but for small-bodied organisms like birds, this is a difficult question to answer.


In a recent paper in the Proceedings of the National Academy of Sciences, Richard Duncan, Alison Boyer and Tim Blackburn use sophisticated methods to estimate the true magnitude of bird (specifically nonpasserines –i.e., not perching or songbirds) extinctions on 41 Pacific islands (including islands from Hawaii, Melanesia, Micronesia and Polynesia). Estimating the number of extinctions prior to recorded history is an extremely difficult exercise, but Duncan and colleagues use a set of statistical methods (Bayesian mark-recapture) to produce reliable estimates. The data available include a spotty fossil record, and so the researchers needed an appropriate estimate of the number of species present on islands in the past. To do this they examined the fossil record and compared it to species that are found there today. Only a subset was found in the fossil record. From this, they determined how the number of fossils found, body size of the organisms and island size affected detection probability. With these informative detection probabilities, they were able to estimate past richness and compare that to today’s richness – and the difference is the number of extinctions.

Across these 41 islands, Duncan et al. estimate that human colonization resulted in at least 983 extinctions. Nine-hundred and eighty-three species are no longer with us because of the presence of humans. Coupled with human activities elsewhere, from over-hunting, habitat destruction and the introduction of non-native species, we responsible for thousands of extinctions. For the first time in Earth’s history, a single species (us) is the direct cause for thousands of other species going extinct. A paper such as this is an important analysis, but it certainly doesn’t make us feel good about ourselves.

Duncan, R., Boyer, A., & Blackburn, T. (2013). Magnitude and variation of prehistoric bird extinctions in the Pacific Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1216511110

Wednesday, April 3, 2013

Gendered assumptions and science: still a problem

Sometimes I feel like covering sexism and science has the potential to trigger a weary response, a feeling that this is well-travelled territory. And generally, academia is fairly self-aware about the causes and consequences of its current gender gap (see the special issue in Nature). But then I hear or read something that disappointingly reminds me that society as a whole still has a ways to go.

The first was a minor story. The curator of “I f--king love science”, a widely-followed Facebook page on things scientific and otherwise, happened to reveal that they were Elise Andrew--a female. While this seemed to be a non-event, apparently young men everywhere (i.e. on the internet) were shocked that their mental picture of a male scientist was untrue. Many comments fell along the lines of “you’re a girl?!” and “all that time picturing a man!”. Even more frustrating was that commenters also mentioned Elise’s appearance – attractive and female and a scientist--apparently this was so surprising as to be worthy of comment. And while I wanted to dismiss this as being limited to problems with Internet culture and hardly indicative of larger societal trends, something else happened – Yvonne Brill, a brilliant American rocket scientist passed away. Her work on propulsion systems now helps keep communications satellites in orbit, and she was a successful engineer with an interesting career. She clearly deserved a national obituary, and she got one in the New York Times. It started:

“She made a mean beef stroganoff, followed her husband from job to job and took eight years off from work to raise three children. “The world’s best mom,” her son Matthew said.

But Yvonne Brill, who died on Wednesday at 88 in Princeton, N.J., was also a brilliant rocket scientist, who in the early 1970s invented a propulsion system to help keep communications satellites from slipping out of their orbits.”

By way of comparison, not one of Steve Jobs’ obituaries started with a mention of his hobbies or personal accomplishments, or his status as a father. The only other recently (2012) deceased female scientist I could think of, astronaut Sally Ride, similarly received an obituary in the NYT that emphasized her gender - "American Woman Who Shattered Space Ceiling".

The need of society, reporters, and popular culture to reconcile a female scientist’s gender with their occupation appears to still be common. So much so that the one science writer came up with the Finkbeiner Test (Columbia Journalism Review) to point out articles which rely on the “she’s a woman AND a scientist” trope. Such articles tend to mention:
  • The fact that she’s a woman 
  • Her husband’s job 
  • Her child-care arrangements 
  • How she nurtures her underlings 
  • How she was taken aback by the competitiveness in her field 
  • How she’s such a role model for other women 
  • How she’s the “first woman to…” 
The point is not that it is always unacceptable to include such things in articles, but that unless the article is about sexism or balancing work-life balance, these facts are irrelevant when reporting on a scientist's professional accomplishments. Gender shouldn't be the default position when we consider scientists who happen to be women. And apparently this message still needs to be repeated. Some people have suggested that one equalizer is to simply to also ask male scientists about their personal lives more often. However writer Finkbeiner notes that these questions rarely improve science journalism: "They’re [scientists] all normal human beings and the thing that makes them so interesting is the science. So, if you want to humanize them, talk about their motivations. Talk about how they got interested in their field. Talk about the part of their life that led them to become such an interesting scientist—because childcare is not interesting."

Note: while problems with gendered assumptions is a very general societal issue, academia isn't totally blameless. Having served on a number of lecture organizing committees, I've noticed that if the email for speaker nominations doesn't explicitly say that we wish to nominate male and female scientists at the top of their careers, female scientists are rarely nominated. Students' mental image of a top scientist tends to skew male. If that simple note is included though, nominations begin to approach gender ratios for professors at that career stage.

Tuesday, April 2, 2013

Carbon sequestration in boreal forests: below-ground interactions matter


One of the most important developments in plant ecology over the last 20 or so years is the inclusion of belowground interactions with fungi into traditional studies of plant diversity, productivity, and ecosystem functions. Results like those from van der Heijden (1998)--which showed experimentally that the assumed link between ecosystem function and plant diversity was actually driven by arbuscular mycorrhizal fungal diversity (through their effects on plant communities)—must alter how we see plant community dynamics. Not only does this reinforce the importance of complexity in ecology, but more specifically it suggests that if fungi are a necessary component of plant community identity and function, they must be explicitly considered in management and conservation plans.

For example, an important current issue is the question of which ecosystems will be carbon sinks as part of a focus on atmospheric CO2 levels. Understanding the mechanisms by which carbon is stored is therefore an important topic. Boreal forests sequester net amounts of carbon in soil and it is generally assumed that this is as a result of plant litter and organic matter accumulating in soil. Clemmensen et al. (2013) examined soil chronosequences for forested islands in Sweden to test whether this hypothesis held. These islands differed in the frequency of fire occurrences, between large and frequently burnt islands and smaller, infrequently burnt islands.

The authors identified the age since fixation of C found in the chronosequences and used models of C source to look at the relative contribution of the two possible processes: either fixation of C through aboveground plant litter or below-ground inputs through root-associated fungi. Carbon input tended to be higher on the small islands that were burnt less often, and this was associated entirely with root-derived input. Further, DNA barcoding showed that on these small islands, there were mycorrhizal fungi associated with the soil depths where the root-derived inputs were occurring. On islands which burned more frequently, and had lower carbon input, fungi were absent at these depths (figure below). This difference in fungal profile was related to the fact that infrequently burnt islands had older mycelium with low turnover, hence greater carbon sequestration.
From Clemmensen et al (2013). A) Fungal functional groups associated with soil depths on large, frequently burnt islands (panel 1) and small, infrequently burnt islands (panel 2).

The authors convincingly show that, at least in some ecosystems, the view that decomposition of litter primarily drives humus accumulation (and the accompanying carbon sequestration) must be tempered with the knowledge that organic layers also accumulate from below by roots and root-associated fungi. This suggests that there is a need to consider fungal communities as well as plant communities for when managing forests and making inventories of global carbon stores. And probably a need to consider fungi much more often in general.

Monday, March 18, 2013

Evolution on an ecological scale


Andrew Gonzalez, Ophélie Ronce, Regis Ferriere, and Michael E. Hochberg. 2013. Evolutionary rescue: an emerging focus at the intersection between ecology and evolution. Philos Trans R Soc Lond B Biol Sci. 368 (1610).doi: 10.1098/rstb.2012.0404 (Intro to special issue).

David A. Vasseur, Priyanga Amarasekare, Volker H. W. Rudolf, Jonathan M. Levine. 2011. Eco-Evolutionary Dynamics Enable Coexistence via Neighbor-Dependent Selection. The American Naturalist, Vol. 178, No. 5, pp.E96-E109.

Ecology and evolution are often treated as connected but ultimately discrete areas of study. Ecological processes are usually the main source of explanation for ecological patterns and  ecologists may ignore evolutionary processes under the assumption that these are most important over longer time scales than are of interest (e.g. speciation). However, there is also an increasing recognition that rapid evolutionary dynamics can contribute to ecological observations. In a time where rapid changes to climate and habitat are the greatest threats to most species, the suggestion that rapid evolution might play a role in extinction prevention and diversity maintenance is an important one.

Increasingly researchers are exploring this concept. The concept of evolutionary rescue (ER), has been particularly championed by Andy Gonzalez and Graham Bell of McGill University. ER results when evolution occurs fast enough to arrest population declines and allow populations to avoid extinction in the face of changing conditions. Changing conditions resulting in maladapted populations should result in population declines followed by extinction. However, if selection for resistant types (which are present in the population, or result from mutations) occurs, population declines can be countered. The result is a characteristic u-shape curve, showing the initial geometric decline, followed by a geometric increase – escape from extinction is then a balance between rates of evolution and success of resistant types compared to rates of population decline.
From Bell & Gonzalez 2009.
The question of whether evolution may have relevance to population declines is not precisely new, but it is especially relevant given we are in a period of habitat changes and extinction. A special issue of Proc B is focused only ER, on the question of its importance, prevalence, and predictability. Many of the articles extend theory, exploring assumptions about the type of environmental change, type and extent of the threat, presence of dispersal, spatial gradients, etc. A few articles attempt the more difficult task of testing for ER in natural systems and assessing its likely prevalence and value to conservation activities. It is an interesting journal issue and a great example of the importance of context in determining when an idea takes off. The theoretical background for evolutionary rescue has existed for many years, but it took the context of climate change (and perhaps the collaboration of an ecologist and evolutionary biologist?) for it to gain ground as an area of ecological research.

Another interesting paper, this one linking evolutionary dynamics with community coexistence, is from Vasseur et al. (2011). In this case, the authors suggest an evolutionary mechanism that could augment coexistence when ecological conditions allow for niche partitioning and that could allow coexistence when ecological conditions lead to competitive exclusion. If species exhibit tradeoffs between traits that are optimal for intraspecific interactions and traits that are optimal for interspecific interactions, evo-ecological dynamics can produce coexistence. Such tradeoff means that a species will be a superior interspecific competitor when rare and a poor interspecific competitor when common. Such a tradeoff creates neatly alternately selective pressures depending on whether a species is common (fitness declines) or rare (fitness increases). This is presented as a theoretical model, but it seems like in a tractable system one could easily test for changes in ecological and evolutionary pressures as predicted by the model.

No one would argue with the conclusion that a closer relationship between ecology and evolutionary biology would be beneficial for both. But in practice this seems to be the exception rather than the rule. "Evolutionary ecology" as it exists is fairly restricted, and if complaints about seminar topics is to provide a hint, most ecologists feel disconnected from evolutionary topics and vice versa. If evolutionary dynamics are relevant on an ecological scale, it seems that we should at least attempt to understand their prevalence and importance in natural systems.


Monday, March 11, 2013

Ecology in everyday life: Monday links

To start, it’s reassuring to know that honeybees like caffeine too. So as you sip your coffee, know that you aren’t the only species who benefits from a little something to start the day.

Citizen science success. iNaturalist.org provides a platform for interested citizens to collect and submit observational data for a huge variety of taxa. This creates an expanding database of species IDs and geographical locations across the US. At present, they have 200,000 observations, which is pretty amazing.

Beautiful wildlife gifs, a reminder that nature is an astonishing place.

Predator/Prey. For some ecologists, work and creative undertakings overlap. So with this in mind, I wanted to point out a band that has taken this marriage of art and ecology to the extreme. Predator/Prey is a Canadian band headed by Dak de Kerhove and Adam Phipps that has released an album built around the concept of species interactions. Dak de Kerkhove is a PhD student studying predator-prey interactions between fish with Peter Abrams and Brian Shuter, so in this case art imitates life.

Most of the songs take inspiration from a combination of emotional subtext and ecological theory. For example, “A Run of Rabbits” focuses on prey dynamics and red queen, with the prey ever running to stay in one place. “Plump of Grouse” is inspired by death and predator prey cycles and written from the perspective of a predator. Because de Kerkhove's work has taken him to the far North, the band can't tour, and instead decided to release a web game that allows you to experience predator-prey interactions from the perspective of a fox. Pretty cool.

**The ecological connections are sometimes subtle, so here is the cheat sheet I was given**
Unkindness of Ravens (INTELLIGENCE / MUTUALISM)
Bed of Mussels (ENDURANCE / PASSIVE FORAGING)
Sounder of Boar (REVENGE / LOSS OF TRAITS UNDER DOMESTICATION)
Knot of Snakes (DESIRE / MATE COMPETITION)
Skulk of Foxes (LOSS / MONOGAMY)
Rout of Wolves (POWER / SOCIAL HIERARCHY)
Priory of Panthers (COOPERATION / GAME THEORY)
Plump of Grouse (DEATH / PREDATOR PREY CYCLES)
Mischief of Mice (OVERWHELMED / COMPETITION)
Shoal of Fish (DEDUCTION / CREPUSCULAR FORAGING)
Run of Rabbits (FEAR / RED QUEEN)
Gang of Elk (ACCEPTANCE / SELFISH HERD)
Piteousness of Doves (LOSS / GAME THEORY) 
                           ****

Wednesday, March 6, 2013

Can you lecture through Twitter?

The question is intriguing, and recently David Shiffman taught a marine bycatch lecture entirely on Twitter. It seems like an excellent way to reach a broad audience and a novel use of social media. I would be interested to know how the participants felt about the content detail. Universities have been diminishing the classroom experience, in favor of online courses, but this Twitter exercise maintains contact with the instructor (as opposed to pre-recorded videocasts with discussion boards monitored by a TA).

Tuesday, March 5, 2013

Evolution of conservation – what counts?

Winter, M., Devictor, V. and Schweiger, O.. 2013. Evolutionary diversity and nature conservation: where are we? Trends in Ecology and Evolution. http://dx.doi.org/10.1016/j.tree.2012.10.015

and the response:

Rosauer, D.F. and Mooers, A.O. 2013. Nurturing the use of evolutionary diversity in nature conservation. Trends in Ecology and Evolution. http://dx.doi.org/10.1016/j.tree.2013.01.014

The problem has been called the agony of choice – available resources for conservation are dwarfed by need. And as a result, we are forced to prioritize, to save some species and lose others. Much of the attention given to phylogenetics in ecology lately is on its use, questionable or otherwise, in ecophylogenetic metrics. However the important and useful research being done relating evolutionary information to conservation decisions deserves more attention.

This work has created a recurrent and sometimes contradictory discussion about whether evolutionary relationships contribute complementary information to traditional conservation targets (e.g. biodiversity, habitat types) and whether such information can easily be incorporated into conservation activities (e.g. Rodrigues et al. 2005; Faith 2008; Rodrigues et al. 2011; Tucker et al. 2012 etc.). A couple of papers recently in TREE are continuing this discussion and together do a nice job of summarizing the state of evolutionarily informed conservation practices. Most interesting about the article and the response is that even the opposing sides of the discussion appear to be converging on the same conclusion—that evolutionary diversity should be incorporated into conservation decisions—and differ primarily in how they justify this and the extent to which they feel it will be useful.

Phylogenetic diversity (PD) can be defined specifically as a measure of evolutionary diversity, however here it is more generally defined as the evolutionary information (e.g. phylogenetic relatedness) represented in a community and a common measure of evolutionary information. A community with high PD might include many distantly related species and hence represent many branches in a phylogenetic tree. The simplest argument for why PD might inform conservation is that maximizing PD will maximize the range of species’ ecologies and function that is conserved. In contrast, species richness targets have no relation to a community’s functionality.

Although the conservation literature includes many studies of phylogenetic diversity that are oriented towards real-world applications, in practice, conservation activities rarely incorporate PD. Winters et al. seem lukewarm about the value of phylogenetically informed approaches (one header is “A promising but yet ambiguous additional biodiversity component for conservation”). They suggest that there are a number of ways in which phylogenetic diversity can be informative: it can act as a measure of rarity and facilitate decision-making if rarity is a priority (and perhaps other measures of rarity not available) (e.g. http://www.edgeofexistence.org/). It may act as additional information to be incorporated with measures of species richness – areas with similar richness may have very different amounts of PD. However, the authors question “But what would the added value of conserving areas or communities of unexpectedly high phylogenetic diversity, or spending money on phylogenetically eroded areas, actually be?” The most common arguments, they suggest, are that phylogenetic diversity is a proxy for functional diversity and/or a measure of the evolutionary potential of a community. However, since ecological/functional similarity is not always correlated with PD, and evolutionary potential is not related to PD in a predictable manner, these are inadequate.

Winters et al. seem to suggest that PD is valuable because it can (but not always) act as a proxy for things we actually want to account for (rarity, etc). This is the point that the response from Rosauer and Mooers has the hardest time with. Why does evolutionary diversity not have intrinsic value if, say, species diversity does? Further, species richness is objectively a poor measure of diversity, since it treats all species as having equal value. In contrast, phylogenetic measures of diversity already account for one difference (evolutionary distinctiveness) between species, and hence should already be more effective in capturing total diversity in an assemblage. Rosauer and Mooers state “In an era of triage, difficult decisions are being made, and we know that inclusion of [evolutionary diversity] could make a substantial difference to the outcome for biodiversity, suggesting that it should be considered as one among many criteria”.

Regardless of differences in motivation, both authors agree that the greatest barrier is actually in bringing these ideas into practice. There are many ways of measuring evolutionary diversity (and species diversity, if we’re being fair) and choosing the correct metric can be a minefield. Calculating measures of evolutionary relationship requires specialized knowledge. On the other hand, it is easier and faster than ever to generate phylogenetic trees using DNA sequence databases and available software. Further, evolutionary information lacks the attractiveness that taxonomic-focused conservation has (it is more exciting to save the tigers than the genes). So what remains is to make the jump from theory and case studies to practice, and to find ways to explain why an echidna should receive more protection than all the other rodents. But if evolutionary information makes the agony of choice a little less, it is a worthy goal.
The power of phylogenies?
(Lanna Jin)
Cited
Faith D.P. (2008). Threatened species and the potential loss of evolutionary diversity: conservation scenarios based on estimated extinction probabilities and phylogenetic risk analysis. Conservation Biology, 22, 1461-1470.
Rodrigues A.S.L., Brooks T.M. & Gaston K.J. (2005). Integrating evolutionary diversity in the selection of priority areas for conservation: does it make a difference? In: Phylogeny and conservation (eds. Purvis A, Gittleman JL & Brooks TM). Cambridge University Press Cambridge, UK, pp. 101-199.
Rodrigues A.S.L., Grenyer R., Baillie J.E.M., Bininda-Emonds O.R.P., Gittleman J.L., Hoffmann M., Safi K. & al. e. (2011). Complete, accurate, mammalian phylogenies aid conservation planning, but not much. Philosophical Transactions of the Royal Society, London, B, 1579, 2652-2660.
Tucker C.M., Cadotte M.W., Davies T.J. & Rebelo A.G. (2012). The distribution of biodiversity: linking richness to geographical and evolutionary rarity in a biodiversity hotspot. Conservation Biology, 25:2.
Vane-Wright (1991). What to protect - systematics and the agony of choice. Biological conservation, 55, 235-254.