Half-time seminar on micro- and macroevolution by PhD-student John Waller (February 2, 13.00)

Posted by Erik Svensson 

As you already hopefully know, we will have our regular EXEB meeting in the morning of February 2 on the topic "Can the evoutionary process learn?", and it is Tobias Uller who organizes this interesting seminar. 

Later the same day, in the afternoon, there is another interesting EXEB-event: one of the PhD-students in the EXEB environment (John Waller), will have his half-time seminar with the following title:


"Connecting microevolutionary processes and macroevolutionary patterns in damselflies and dragonflies"

Locale: "Red Room", Ecology Building
Date and time: Tuesday, February 2, 13.00 

As many intern students, field and lab assistants have helped John to collect data for his PhD-work, we wish all those and others within and outside the EXEB-environment most welcome to this interesting seminar. Dr. Lars Råberg (Functional Zoology Unit), will be the opponent on John's half-time seminar and report. 

Can the Evolutionary Process Learn?

Posted by Tobias Uller

Next week I thought we would discuss an opinion piece in TREE by Richard Watson and Eörs Szathmary. The thought-provoking suggestion - based on insightful use of learning theory - is that the basic ingredients of evolution (organismal variation, differential reproductive success, and inheritance) evolve in ways that make evolution a more directed process than we might think. Richard and Eörs explain the basics and apply the logic to evolvability, ecosystems and major transitions.

Paper can be found here, abstract below.

Time: Tuesday, Feb 2, at 10.00

Where: "Argumentet", 2nd floor, Ecology Building

Coffee guaranteed and there is a decent chance of kanelbulle

Abstract

The theory of evolution links random variation and selection to incremental adaptation. In a different intellectual domain, learning theory links incremental adaptation (e.g., from positive and/or negative reinforcement) to intelligent behaviour. Specifically, learning theory explains how incremental adaptation can acquire knowledge from past experience and use it to direct future behaviours toward favourable outcomes. Until recently such cognitive learning seemed irrelevant to the ‘uninformed’ process of evolution. In our opinion, however, new results formally linking evolutionary processes to the principles of learning might provide solutions to several evolutionary puzzles – the evolution of evolvability, the evolution of ecological organisation, and evolutionary transitions in individuality. If so, the ability for evolution to learn might explain how it produces such apparently intelligent designs.

Jan. 26th: Major evolutionary transitions

Posted by Jessica Abbott

For the next meeting I've chosen a paper about one of the big ideas in evolutionary biology, that of the major evolutionary transitions during the history of life. This paper examines under what conditions a major evolutionary transition can occur.

Title: Major evolutionary transitions in individuality

Abstract: The evolution of life on earth has been driven by a small number of major evolutionary transitions. These transitions have been characterized by individuals that could previously replicate independently, cooperating to form a new, more complex life form. For example, archaea and eubacteria formed eukaryotic cells, and cells formed multicellular organisms. However, not all cooperative groups are en route to major transitions. How can we explain why major evolutionary transitions have or haven’t taken place on different branches of the tree of life? We break down major transitions into two steps: the formation of a cooperative group and the transformation of that group into an integrated entity. We show how these steps require cooperation, division of labor, communication, mutual dependence, and negligible within-group conflict. We find that certain ecological conditions and the ways in which groups form have played recurrent roles in driving multiple transitions. In contrast, we find that other factors have played relatively minor roles at many key points, such as within-group kin discrimination and mechanisms to actively repress competition. More generally, by identifying the small number of factors that have driven major transitions, we provide a simpler and more unified description of how life on earth has evolved. 

Time and place: 10:00-11:00 January 26th, in Argumentet

Spring 2016 semester schedule for EXEB-meetings

Posted by Erik Svensson

Following a Doodle poll about which dates EXEB-members would be present and could participate and take care in organizing our regular (weekly) Tuesday-meetings, I have now put together a tentative schedule for spring 2016. Everybody except one has participated in this poll, and I have now allocated you dates based on this poll.

As usual, the person(-s) responsible for organizing a meeting decide the activitiy, which is often (although not always) to discuss an interesting scientific paper or, alternatively, to give a short (informal) presentation of ongoing research. Also as usual, it is a the person(-s) responsible who will write a blog post, announcing the theme of the meeting. Ideally, this blog post should be up on Thursday or Friday the week before, particularly if it is a paper to be discussed, as people will need time to digest the material. 

Note that, although we are quite many now in the EXEB-environment, some of us will have to arrange two meetings this semester to fill the slots, which is hopefully not too painful.

Also, feel free if you have a visitor to let him/her present his research in this informal and relaxed scientific environment. If you have to cancel your slot, make sure you find a substitute or swich date with someone else on the list.

EXEB schedule spring 2016 (tentative and subject to change)

Tuesday, January 19: Erik Svensson

Tuesday, January 26: Jessica Abbott

Tuesday, February 2: Tobias Uller

Tuesday, February 9: Katie Duryea

Tuesday, February 16: Nathalie Feiner

Tuesday, February 23: Katrine Lund-Hansen

Tuesday, March 1: John Waller

Tuesday, March 8: Reinder Radersma

Tuesday, March 15: Talk by Wiebke Feindt (host: Erik Svensson)

Tuesday, March 22: Hanna Laakonen

Tuesday, March 29: Weizhao Yang

Tuesday, April 5: Anna Nordén

Tuesday, April 12: Beatriz Willink

Tuesday, April 19: Antonio Cordero

Tuesday, April 26: Erik Svensson

Tuesday, May 3: Jessica Abbott

Tuesday, May 10: Tobias Uller

Tuesday, May 17: Katie Duryea

Tuesday, May 24: Nathalie Feiner

Tuesday, May 31: Katrine Lund-Hansen

First EXEB-meeting in 2016: on speciation, ecological opportunity and latitude

                                



















Crab spider (Misumenia vatia) with prey. Photo: Erik Svensson

Posted by Erik Svensson 

"Evolution in Sweden 2016" is now over, and in my opinion it was a great success. You can see photos from this meeting here, and we can also briefly summarize our general reflections about this meeting on the first EXEB-meeting, which I post information about below. 

On this first EXEB-meeting of 2016, I want to discuss a recent paper published as a "Presidential Adress" in American Naturalist by Dolph Schluter, entitled "Speciation, ecological opportunity and latitude". 

I saw Dolph give a talk about this last year at a speciation-meeting in California, and I think that he is a very thoughtful scientist who has stimulated my thinking and influenced many other ecologists and evolutionary biologists. Hopefully, we will have a good discussion about this paper. But as usual, we will start the meeting with some general reflections, summary of impressions of "Evolution in Sweden 2016" and we can also hear a bit from Tobias and Nathalie's trip to Australia, as well as mine, Katie's and John's trip to Argentina. I might even bring some pictures to show. 

Time: Tuesday, January 19, at 10.00

Where: "Argumentet", 2nd floor, Ecology Building

Abstract: Evolutionary hypotheses to explain the greater numbers of species in the tropics than the temperate zone include greater age and area, higher temperature and metabolic rates, and greater ecological opportunity. These ideas make contrasting predictions about the relationship between speciation processes and latitude, which I elaborate and evaluate. Available data suggest that per capita speciation rates are currently highest in the temperate zone and that diversification rates (speciation minus extinction) are similar between latitudes. In contrast, clades whose oldest analyzed dates precede the Eocene thermal maximum, when the extent of the tropics was much greater than today, tend to show highest speciation and diversification rates in the tropics. These findings are consistent with age and area, which is alone among hypotheses in predicting a time trend. Higher recent speciation rates in the temperate zone than the tropics suggest an additional response to high ecological opportunity associated with low species diversity. These broad patterns are compelling but provide limited insights into underlying mechanisms, arguing that studies of speciation processes along the latitudinal gradient will be vital. Using threespine stickleback in depauperate northern lakes as an example, I show how high ecological opportunity can lead to rapid speciation. The results support a role for ecological opportunity in speciation, but its importance in the evolution of the latitudinal gradient remains uncertain. I conclude that per capita evolutionary rates are no longer higher in the tropics than the temperate zone. Nevertheless, the vast numbers of species that have already accumulated in the tropics ensure that total rate of species production remains highest there. Thus, tropical evolutionary momentum helps to perpetuate the steep latitudinal biodiversity gradient.

Merry Christmas and Happy New EXEB-year!

Posted by Erik Svensson

The year 2015 is approaching the end, and I wish all EXEB-members a Merry Christmas and a Happy New Year. I think we have had a great year and many exciting and intellectually stimulating lab-meetings where (at least I) have learned a lot and got many new insights. EXEB has grown rapidly in short time - particularly since Tobias Uller have recruited several new co-workers - and we do now also have several hardworking interns, field assistants, laboratory assistants, PhD-students, Master's students and postdocs. All our permanent and temporary co-workers - nobody mentioned, nobody forgotten - do a tremendous job, both in terms of actual work performed, but also in contributing to a friendly and intellectually stimulating research environment.

Some statistics: If we count only the "core" EXEB members (who are in Lund and have formal positions), we are 11 in total (3 PI:s, 3 PhD-students, 4 postdocs and one research engineer). Counting a bit more generously, we are 13, since we have two affiliated PhD-students from Sussex University (Katrine Lund-Hansen)  and Manchester University (Miguel Gomez), who Jessica Abbott and I are co-advisors of, respectively.

Looking back upon 2015 in terms of research achievements, it has been a very succesful year, I think we can say without any hesitation. I have not made an official tally of joint publications, but I note that Tobias team had an interesting article about asymmetric species interactions in hybrid zones of lizards in Ecology Letters, and Jessica published a model paper about how self-fertilization and inbreeding might limit sexual antagonism in Journal of Evolutionary Biology. As for myself, I was happy to get our long-term time-series analysis of the signature of negative frequency-dependent selection in damselfly morphs published in American Naturalist. John Waller got his first thesis-chapter about imperfect detection and mark-recapture analysis of selection published in Methods in Ecology & Evolution. Lastly, and importantly, Jessica Abbott was awarded an ERC Starting Grant in October, the first of two at the Biology Department in Lund. All in all, a very succesful year for EXEB and its members, I think.

The future looks bright, I think, if the trend in 2015 will continue, but now for something lighter: the evolutionary origin of Santa Claus. It was Beatriz Willink pointed me to this very interesting blog post, which aims to do a phylogenetic analysis of the evolutionary origin and allopatric divergence of different Santa Claus phenotypes. It is from the blog "EEB and Flow", and R-code is provided, should you be interested in exploring this fascinating topic in depth. Enjoy!

Lab meeting on 8th of December: Genomic targets of natural selection on bill morphology

Posted by Hanna Laakkonen

Martin Stervander's cool PhD is out and since there is a lot of interesting reading in the book I suggest we pick a paper from there for next Tuesday. This topic is a manuscript, but Martin was kind to provide us the pdf for reading. I'll print out a few copies and put them into my pigeon hole, pick one from there if your missing the actual thesis!

Title: Identifying the genomic targets of natural selection on bill morphology in the Inaccessible Island finch Nesospiza acunhae

Abstract: Adaptation to food sources is a key element in divergence processes, and may promote ecological speciation in the face of gene flow. In birds, the size and shape of the bill is the target for natural selection on feeding efficiency, and it can also affect male song, a sexually selected trait. Here, we investigate the Inaccessible Island finch Nesospiza acunhae, part of a small radiation endemic to the South Atlantic islands of Tristan da Cunha. Inaccessible Island hosts two subspecies: a smallbilled generalist feeding mainly on grass seeds, and a large-billed specialist foraging on the seeds of Phylica trees. Notably, despite the extremely small geographic scale – Inaccessible Island is only 16 km2 – there is simultaneous occurrence of strong bill size-associated assortative mating, and parallel hybridization between the two subspecies in confined parts of the highland plateau. Here we report on the genomic landscape of bill morphology and detect two genomic regions with significantly elevated differentiation between small- and large-billed birds. The first region, on chromosome 1, contains 4–6 genes, of which one (KPNA3) is part of a large pathway where several bill morphology candidate genes are included. The second region, residing on the sex chromosome Z, contains 8 genes, all of which are associated with previously known bill morphology candidate genes. One of them is ISL1, a homeobox transcription factor included in the neural crest differentiation pathway, which affects bill morphology in Darwin’s finches through the expression of bone morphogenetic proteins. The effect of the combined chromosome 1/Z genotypes on bill phenotype indicates an epistatic interaction between the regions. Our results show that minute proportions of the genome contribute to extreme bill variation in the Inaccessible Island finch, which in turn is associated with strong differential food preference, habitat selection and assortative mating.