New lab-meeting on micro- and macroevolution of body size

Since this week's lab-meeting discussion about Anna's presentation took longer time than planned, we will discuss the paper by Uyeda et al. in PNAS this coming Tuesday instead, in "Argumentet" (13.00-15.00). Hope to see you all there, and I recommend you to read this important paper in detail before the meeting to have a good and productive discussion. Also, do not forget to take a look at Jerry Coyne's blogpost about the paper which you can find here.

Visit by Peter and Rosemary grant and lab-meeting this week

This will be quite an exciting week at our department. On Thursday and Friday, we are visited by legendary evolutionary biologists Peter and Rosemary Grant (Princeton University), who are famous for their long-term population and ecological studies of Galápagos Finches on Daphne Major. Rosemary will give a seminar on Thursday (October 6) at 13.15 (note! Not usual time at 14.00) in the "Blue Hall", entitled:  "Evolution of Darwin's Finches: the role of genetics, ecology and behaviour".

The next day, on October 7, Peter will introduce a reseach symposium in honour of the Grant couple with the theme "Microevolution in the wild". This symposium starts at 08.30, with Peter's talk which is entitled: "Microevolution in Darwin´s finches". Other contributions to this symposium comes from two members of our research lab: Anna Runemark and Maren Wellenreuther. The full programme can be found here.


Anna would like to have some feedback an input on her presentation, before the symposium, and we will therefore listen to her during our lab-meeting this week, which will take place on Thursday, October 6 at 10.00 in the seminar room "Fagus" (3rd floor, Ecology Building). Anna will bring fika. After her presentation, we will discuss a recent paper in PNAS, about the link between microevolution and macroevolution, by Uyeda, Hansen, Arnold and Pienaar entitled: "The million year wait for macroevolutionary bursts".

This is a very important paper that adresses the issue of (apparent) evolutionary stasis in phenotypic traits, and how to reconcile this with the observation that natural (and sexual) selection is generally considered to be strong in natural (contemporary) populations, and the fact that there appears to be abundant additive genetic variance for rapid evolutionary change. Yet, it seems to seldom happen, and this is what we are going to discuss. You will find the title and Abstract below. I would also like to recommend the interesting post by Chicago-professor and population geneticist Jerry Coyne who comments upon their findings at his blog "Why Evolution is True". The title of his post summarizes very well the main finding by Uyeda et al: "Want evolutionary change? Wait a million years".

The million-year wait for macroevolutionary bursts

1. Josef C. Uyeda^a,¹,
2. Thomas F. Hansen^b,
3. Stevan J. Arnold^a, and
4. Jason Pienaar^c

+ Author Affiliations

1. ^aDepartment of Zoology, Oregon State University, Corvallis, OR 97331;
2. ^bDepartment of Biology, Centre for Ecological and Evolutionary Synthesis, University of Oslo, 0316 Oslo, Norway; and
3. ^cDepartment of Genetics, University of Pretoria, Pretoria, South Africa 0002

Abstract

We lack a comprehensive understanding of evolutionary pattern and process because short-term and long-term data have rarely been combined into a single analytical framework. Here we test alternative models of phenotypic evolution using a dataset of unprecedented size and temporal span (over 8,000 data points). The data are body-size measurements taken from historical studies, the fossil record, and among-species comparative data representing mammals, squamates, and birds. By analyzing this large dataset, we identify stochastic models that can explain evolutionary patterns on both short and long timescales and reveal a remarkably consistent pattern in the timing of divergence across taxonomic groups. Even though rapid, short-term evolution often occurs in intervals shorter than 1 Myr, the changes are constrained and do not accumulate over time. Over longer intervals (1–360 Myr), this pattern of bounded evolution yields to a pattern of increasing divergence with time. The best-fitting model to explain this pattern is a model that combines rare but substantial bursts of phenotypic change with bounded fluctuations on shorter timescales. We suggest that these rare bursts reflect permanent changes in adaptive zones, whereas the short-term fluctuations represent local variations in niche optima due to restricted environmental variation within a stable adaptive zone.

 

The controversy over kin selection in the evolution of eusociality

In our next lab-meeting, we will dive in to the recent controversy over kin selection and its utility in explaining the evolution of eusociality in social insects. This controversy started with a provocative paper in "Nature" by Martin Nowak, Corina Tarnita and Edward O. Wilson, which you can download here. Basically, these three authors argue that kin selection is neither necessary nor sufficient to explain the evolution of eusociality, but that standard natural selection theory is sufficient. It is not surprising that this paper has been met by an outcry from many researchers in social evolution, and they have got a severe criticism in this paper, with a lot of different co-authors. Nowak et al. defend themselves against the many critics here.

Who is right? Well, it is up to us to make up our own opinion, after we have read these three papers! We will meet on Friday May 13 at 10.30 in "Argumentet" to discuss these three rather short papers.

For those of you who are interested more in this debate and want some different viewpoints, I can recommend this blogpost by Jerry Coyne who, not surprisingly, is very critical of Nowak et al. So is Richard Dawkins. For a counterpoint and an interesting perspective from a classical proponent of group selection, I can recommend this blogpost by David Sloan Wilson, who criticizes both camps, i. e. both Nowak et al. and their critics, and suggest that both have misunderstood the real issues at stake! David Sloan Wilsons blogpost has the challenging and provocative title: "137 Co-authors Can't Be Wrong - and That's The Problem". 

It is certainly a sign of a healthy research field that things like these are intensively debated, and shows that evolutionary biology is as vibrant and exciting as ever, with some fundamentally important controversies that needs to be discussed.