Lab meeting on Nov 3 (10.00h) on Transgenerational Epigenetic Inheritance

Hej,

For next week's lab meeting I would like to discuss the importance of transgenerational epigenetic inheritance in evolution. I selected a paper which gives a nice overview of potential mechanisms and some examples of transgenerational epigenetic inheritance. The paper is already a bit "old" (1.5 year already) and the discussion is focussing on human health, but it gives a nice overview.

Transgenerational Epigenetic Inheritance: Myths and Mechanisms
Cell: Volume 157, Issue 1, p95–109, 27 March 2014

Summary: Since the human genome was sequenced, the term “epigenetics” is increasingly being associated with the hope that we are more than just the sum of our genes. Might what we eat, the air we breathe, or even the emotions we feel influence not only our genes but those of descendants? The environment can certainly influence gene expression and can lead to disease, but transgenerational consequences are another matter. Although the inheritance of epigenetic characters can certainly occur—particularly in plants—how much is due to the environment and the extent to which it happens in humans remain unclear.

Fika will be provided :)

Lab-meeting by Weizhao Yang on Genetic signature of high-altitude adaptation for toads: October 20 (10.00)

Hej!

According to Erik's suggestion, next week on the EXEB-meeting on Tuesday October 20th (10.00 as usual), I will take the opportunity to introduce part of my PhD thesis, genetic signature of high-altitude adaptation for toads.

Asiatic toad  is one of the few amphibians living on the Tibetan Plateau. It has been a true Plateau dweller for approximate 2.5 millions of years and is well-adapted to the environments. In addition, it occupies a large elevational gradient from zero to 4,300m above sea level, which provides excellent opportunities to compare individuals or populations from various altitudes. I implemented a series of experiments to explore the evolutionary genetic signature of altitude adaptation in Asiatic toad, and hope the results could provide useful direction to understand how poikilotherms adapt to high-altitude.

"Fika" will be provided and time and place as usual: "Argumentet" at 10.00.

Congratulations to Jessica Abbott for receiving ERC Starting Grant!

Posted by Erik Svensson 

Last Friday (October 9, 2015), our colleague and one of EXEB:s three PI:s Jessica Abbott found out that she has been awarded an "Starting Grant" from the European Research Council (ERC). This is a very large grant of up to 1.5 million Euro, spread out over a five-year period, and it is highly competitive and prestiguous. 

This ERC-grant will give Jessica the opportunity to further consolidate her research group and hire more postdocs and PhD-students, and will also give her higher job security, as she has sofar only been on a temporary position as Junior Researcher, funded by the Swedish Research Council (VR). It means that we can hopefully soon look forward to see some new faces in the form of students and postdocs at future EXEB-meetings. This will of course further strengthen an already strong and intellectually stimulating scientific environment.

This was the third time Jessica applied for these ERC-grants, and likewise the third time she went to Brussels for an interview with the evaluation panel. Jessica has worked long and hard to get this grant, and she should therefore be proud of this strong achievement. It is the first ERC-grant awarded to any researcher at the Department of Biology in Lund, but hopefully Jessica's example will inspire others to follow in her footsteps.

On behalf of myself, EXEB and many other of our colleagues in the Biology Department and the Evolutionary Ecology Unit, we hereby congratulate Jessica to her achievement. Well done! I am sure you will use this grant money wisely to consolidate your group and develop your research programme further.

 

Lab-meeting 13 October 2015: on neutral theory, ecological drift and the utility of null models in ecology and evolution

Posted by Erik Svensson

For the lab-meeting this forthcoming week, I was thinking we should discuss a short - but hopefully provocative - opinion paper about the utility of the Unified Neutral Theory of Biodiversity (UNTB), which became famous but also controversial about 15 years ago when Stephen Hubbell published his Princeton-monographs. Proponents of the neutral theory, including Hubbel himself, sees UNTB as community ecology's counterpart to the neutral theory of molecular evolution in population genetics, and a rigorous point-of-departure and null model. Opponents - including some leading ecologists like Bob Ricklefs - dismiss UNTB on various empirical grounds. Who is right and who is wrong? Or can both sides be partly right? I hope we can have a good discussion about this.

I also hope to show some  unpublished and preliminary data on these questions from our ongoing research on damselflies and the prospects for ecological drift in these insects. 

Time and place as usual: "Argumentet", October 13 at 10.00.

The case for ecological neutral theory

By:Rosindell, J (Rosindell, James)^{[ 1,2,3 ]} ; Hubbell, SP (Hubbell, Stephen P.)^{[ 4,5 ]} ; He, FL (He, Fangliang)^{[ 6,7 ]} ; Harmon, LJ (Harmon, Luke J.)^{[ 2,8 ]} ; Etienne, RS (Etienne, Rampal S.)^{[ 9 ]}

TRENDS IN ECOLOGY & EVOLUTION

27: 203-208

DOI: 10.1016/j.tree.2012.01.004

Published: APR 2012

Abstract

Ecological neutral theory has elicited strong opinions in recent years. Here, we review these opinions and strip away some unfortunate problems with semantics to reveal three major underlying questions. Only one of these relates to neutral theory and the importance of ecological drift, whereas the others involve the link between pattern and process, the tradeoff between simplicity and complexity in modeling, and the role of stochasticity and drift in ecology. We explain how neutral theory cannot be simultaneously used both as a null hypothesis and as an,approximation. However, we also show how neutral theory always has a valuable use in one of these two roles even though the real world is not neutral.

Visit by US colleague Eben Gering next week: invasion biology and colour evolution of damselflies and chickens

 


Posted by Erik Svensson

Next week (October 12-16), our colleague Dr. Eben Gering from Michigan State University in the US will visit EXEB and the Biology Department. Some of you have already met Eben before, and he visited three years ago during the ISBE Congress in Lund 2012. Eben obtained his PhD at University of Texas (Austin), under the supervision of Prof. Molly Cummings. His thesis-research focused on mechanisms of colour polymorphism maintenance in damselflies and island biogeography. He studied the damselfly Ischnura ramburi (a congener to Ischnura elegans, which we are working on in our lab), and he performed much of his field work on Hawaii.

Currently, Eben is a postdoc at MSU, but he collaborates with a Swedish research group working on chicken genomics at Linköping University, particularly Dominic Wright. On his way to Linköping, Eben thus stops by in Lund and he will participate in our lab-meeting on Tuesday next week (announced in a separate blog post). He will give next week's Thursday seminar on October 15 (13.15) in the "Blue Hall", which will contain data about colour evoution in both damselflies and chickens and a discussion about the evolutionary and genomic consequences of feralization (the opposite of domestication).  

If you are interested in meeting with Eben and discuss his or your research, please contact me (erik.svensson@biol.lu.se), so we can set up a meeting. We also plan to go out for beers at least one evening (tentatively on Wednesday October 14, to "Inferno"), and everybody who wants to attend are most welcome to join in. Below follows more information and an Abstract about Eben's talk.

A tale of two invasions: rapid evolution of color polymorphism in invasive damselflies and chickens

"Darwin and Wallace each struggled to explain the variation in evolution’s color palette. In Darwin’s view, colorful ornaments were a common outcome of sexual selection, whereas Wallace ascribed them to natural selection. A century later, we recognize that both forms of selection interact in complex ways to determine color phenotypes. Here I will describe two case studies of color evolution within invasive populations. Species invasions provide unique opportunities to characterize how traits respond to novel (and often extreme) forms of selection. Surprisingly, our syntheses of historical, genetic and experimental data from invasive chickens and damselflies suggest that density-dependent selection promoted color variability in both groups via very different mechanisms. In damselflies, color polymorphism allowed females to adapt to changes in social environment that ensued invasive spread.  In chickens, plumage variation that resulted from hybridization collapsed during colonization of marginal habitats. While our understanding of these complex systems is far from complete, patterns seen thus far reveal how demographic features of biotic invasions could facilitate rapid evolution by both Darwinian and Wallacian mechanisms." 

On hybrid speciation and genomic architecture in sparrows: visit and talks by two guest from CEES in Oslo

 Posted by Erik Svensson

Next week on the EXEB-meeting on Tuesday October 6 (10.00, as usual) we will have a visit by two PhD-students from  the Centre of Ecological and Evolutionary Synthesis (CEES) at Oslo University, who will give short talks (about 15 minutes) about their researchers. Our two guests are briefly introduced below, and Abstracts of their talks are also provided.

 Caroline and Angelica are PhD-students of Fabrice Eroukhmanoff and Anna Runemark, two
 former EXEB-members who did their PhD in Lund (2010 and 2012, respectively), and who are
 now working on hybrid speciation in Passer sparrows together with Glenn-Peter Saetre and 
 other researchers in the big sparrow project in Oslo.

 "Fika" will be provided and time and place as usual: "Argumentet" at 10.00.



 

    Caroline Øien Guldvog
 

 "As I come from the Oslo area, I did both my bachelor and my MSc here at UiO. For my PhD, I have continued on working with the same research group as I did for my MSc, Glenn-Peter Sætre’s group investigating homoploid hybrid speciation in the Italian sparrow. The work this group is doing originally appealed to be as I find evolutionary genetics very fascinating and would love to continue working within this field in the future. The title of my MSc thesis was «Clock genes and their role in migratory phenotype among Passer sparrows» where I studied genotype-phenotype interactions for migratory behavior among migratory and sedentary populations of birds among the hybrid Italian sparrow and its parentals, the house sparrow and Spanish sparrow. Through this work, I was introduced to genomics and bioinformatics and I am very happy to be able to continue using these skills and learning more through my PhD which has the title "The repeatability of the genomic architecture in a homoploid hybrid species»."

ABSTRACT:

Hybridization has increasingly been recognized as a source of novel variation. The genetic variation resulting from hybridization differs from that from mutations, as large co-adapted complexes can be transferred by hybridization. In addition, variants derived from hybridization have already been tested by selection, further contributing to the potential to form viable new combinations through recombination of genetic elements derived from either parent species. Hybridization will only contribute to adaptation if resulting genotypes are better fit in some environments than the parental species. However, the combination of differentiated genomes typically results in the great majority of recombinants being unfit. In that regard, an interesting question is whether different genomic combinations of the parental species can be produced or if this process is constrained to only result in one or a few viable forms.

The Italian sparrow (Passer italiae) is a homoploid hybrid species resulting from hybridization between the Spanish sparrow (P. hispaniolensis) and house sparrow (P. domesticus). The Italian sparrow is a mix of its parents both on the phenotypic and genetic level. It inhabits the Italian peninsula as well as a few Mediterranean islands including Crete, Corsica and Sicily. The island-living populations differ phenotypically and appear to be derived from different hybridization events and/or to have evolved independently in different directions, making this an excellent system for the study of the repeatability of genomic architecture in a hybrid species. I will present the preliminary plan for my recently started PhD in which the main objective is to study the constraint of the mosaicism of the genome of the Italian sparrow. Populations that differ in both genotype and phenotype will be informative on general processes affecting the hybrid genome such as associations between phenotype and genotype, genetic admixture, patterns of linkage disequilibrium and the role of transposable elements in molding the hybrid genome.

 

Angelica Maria Cuevas Pulido

"My primary research interest lies in the field of evolutionary ecology and genomics of natural populations. I am particularly interested in how variation in genetic architecture affects the
adaptive potential of natural populations and determine the ways in which evolutionary forces
might act on a population. For my PhD I am working on the evolvability of genomic architecture during speciation, using the Italian sparrow as a model species. My project focuses on the genetic basis of adaptive traits in the hybrid species Passer italiae and its parental species. I currently hold a B.Sc. degree in Biology from the Colombian National University and a M.Sc. in Ecology and Evolutionary Biology from the University of Groningen (The Netherlands) and Ludwig Maximilian University of Munich (Germany). I have participated in research projects in different institutions including the Centre d’Ecologie Fonctionnelle et Evolutive, CNRS (France), Harvard University (USA) and Natural History Museum of London (UK)." 

ABSTRACT:

Secondary contact between closely related species can have important evolutionary consequences, including ecological character displacement due to competition. This may be especially true for encounters between a hybrid species and its parents, where strong isolation mechanisms need to evolve for the hybrid to remain stable. Besides the evolution of pre-­‐zygotic isolation and intrinsic reproductive barriers, competition could also play an important role. Some adaptive radiations in birds (e.g. Darwin’s finches) are related to high levels of competition and diversification through beak shape, a trait playing an important role in diet and habitat choice. In the case of hybrid linages, genomic variability may boost evolutionary potential, which could allow rapid evolution in response to species interactions.

I study a population of Italian sparrow (a homoploid hybrid species) before and after a recent secondary contact with one of its parental species, the Spanish sparrow. I show that over just a couple of generations the size of this hybrid population has declined by 60% following the arrival of its parent. Body condition in the Italian sparrow has dramatically decreased and there is strong habitat segregation between the species. The Italian sparrow occupies an animal-­‐farming habitat while its parent is mainly concentrated close to cereal fields. This may reflect severe competition for resources. Beak shape has also changed considerably; the morphospace currently occupied by the Italian sparrow is a subset of the one prior to secondary contact. Hence, this hybrid species appears to be evolving under a very small spatio-­‐temporal scale in response to species interactions.