Zoological Society of London award

 I'm honoured to have been awarded the Zoological Society of London Scientific Medal for 2023. 

Welcome to new PhD student

Welcome to our new PhD student Molly Uzzell, who has been awarded a position in the NorthWestBio Doctoral Training programme. Molly's project, co-supervised with Isabella Capellini in QU Belfast, will be on pre- & post-zygotic reproductive isolation in lizards, and the effects of hybridisation on reproductive success. Molly has been with us as a volunteer since undergrad, then honours and masters - looking forward to the next phase! 

NERC Grant success

 I'm thrilled to share that we have had a Pushing the Frontiers grant funded by NERC. The project is with co-Is Mike Ritchie and Oscar Gaggiotti at St Andrews, Maureen Bain in Glasgow, and Project Partners Jean-François Le Galliard and Pierre de Villemereuil in France and Hans Recknagel in Slovenia. This will support 4 years of research on sex-specific fitness landscapes in oviparous-viviparous lizards. 

welcome to a new postdoc researcher

  Warm welcome to our new and excellent postdoc Hongxin Xie! He's bringing lots of evolutionary and squamate expertise to contribute to our NERC project testing oviparity reversal

 in a collaboration with Amelie Crespel and Shaun Killen, we brought some genomics to an applied evolutionary question - is there evolutionary response to fisheries harvesting? We suspected that forces like size-selective harvest can have impact but what about environmental or demographic context? Open access paper here!

Crespel A, Schneider K, Miller T, Rácz A, Jacobs A, Lindström J, Elmer KR, Killen SS (2021) Genomic basis of fishing-associated selection varies with population density. Proc Natl Acad Sci U S A, 118, e2020833118.

Significance: Fisheries-associated selection is recognized as one of the strongest potential human drivers of contemporary evolution in natural populations. The results of this study show that while simulated commercial fishing techniques consistently remove fish with traits associated with growth, metabolism, and social behavior, the specific genes under fishing selection differ depending on the density of the targeted population. This finding suggests that different fish populations of varying sizes will respond differently to fishing selection at the genetic level. Furthermore, as a population is fished over time, the genes under selection may change as the population diminishes. This could have repercussions on population resilience. This study highlights the importance of selection but also environmental and density effects on harvested fish populations.

Welcome to new lab members!

We welcome two new lab members for autumn 2021 - postdoc Morgane Bonade and PhD student Nic Strowbridge. 

Morgane is working on the project 'do common lizards break Dollo's Law' by reversing back to oviparity? This is a NERC funded project that tests functionally - using genetic crosses, RNAseq, and phylogeny - some hypotheses put forward in our phylogenomic reconstruction that suggested reversal (open access paper here in MPE). 

Nic is an IAPETUS2 doctoral training programme student working on convergent evolution of colouration and toxicity defence in salamanders, in collaboration with Mike Ritchie at St Andrews.

New paper: Functional genetic basis of reproductive mode

Our paper on the genetic basis of parity mode is now published.

The functional genetic architecture of egg-laying and live-bearing reproduction in common lizards

H. Recknagel, M. Carruthers, A. Yurchenko, M. Nokhbatolfoghahai, N.A. Kamenos, M.M. Bain, K.R. Elmer

Nature Ecology and Evolution 2021

SharedIt link: https://rdcu.be/cy5S2

All amniotes reproduce either by egg-laying (oviparity), which is ancestral to vertebrates, or by live-bearing (viviparity), which has evolved many times independently. However, the genetic basis of these parity modes has never been resolved and consequently its convergence across evolutionary scales is currently unknown. Here we leveraged natural hybridisations between oviparous and viviparous common lizards (Zootoca vivipara) to describe the functional genes and genetic architecture of parity mode and its key traits, eggshell and gestation length, and compared our findings across vertebrates. In these lizards, parity trait genes were associated with progesterone-binding functions and enriched for tissue remodelling and immune system pathways. Viviparity involved more genes and complex gene networks than did oviparity. Angiogenesis, vascular endothelial growth, and adrenoreceptor pathways were enriched in the viviparous female reproductive tissue, while pathways for transforming growth factor were enriched in the oviparous. Natural selection on these parity mode genes was evident genome-wide. Our comparison to seven independent origins of viviparity in mammals, squamates, and fish showed that genes active in pregnancy were related to immunity, tissue remodelling, and blood vessel generation. Therefore, our results suggest that pre-established regulatory networks are repeatedly recruited for viviparity and that these are shared at deep evolutionary scales.

This work was supported by NERC, Genetics Society, and a Lord Kelvin-Adam Smith Univ Glasgow PhD studentship

Big thanks to the many fieldwork helpers, young and old.

update: Lizards make the cover, baby! 

New project: Evolution of reproductive mode

We are back in the field and setting up a new experiment on reproductive mode evolution! Delays due to covid are behind us and I'm thrilled to be at CNRS Station for Theoretical and Experimental Ecology and starting our collaboration with ecology legend Jean Clobert. 

First lizard pots are ready and lizards are arriving this week!

This is a NERC funded project with Maureen Bain and Jean Clobert, and the collaboration of Hans Recknagel and new postdoc Morgane Bonade, to dig deeper into the functional development of oviparity in ancestral and derived lineages. Through this experiment we will directly tackle the thorny issue of putative reversal to oviparity ... do lizards break Dollo's Law?

Also perfect timing for some momentum, as our major paper on functional genomics of oviparity vs viviparity is in press. Free online at https://rdcu.be/cy5S2

more new soon!

New paper: reconstructing the history of viviparity in squamate reptiles

 Recently published in the Journal of Evolutionary Biology - 

Evolutionary origins of viviparity consistent with palaeoclimate and lineage diversification

Hans Recknagel, Nicholas Kamenos, Kathryn Elmer

freely available here

a collaboration between evolutionary biology and Geography for reconstruction of palaeoclimate.

It has long been argued that the origin of viviparity is related to cold climatic conditions. However this is challenging to disentangle correlation from causation, and response from cause. Also many studies have examined particular species groups but we have lacked the data so far to estimate a time tree in context of climate. Here led by Hans Recknagel in his interdisciplinary PhD studentship, we showed that stable and long-lasting cold climatic conditions are correlated with transitions to viviparity across squamates. Interestingly, this correlation of parity mode and palaeoclimate is mirrored by background diversification rate in squamates. Further, exploring patterns by simulations of a binary trait also showed a similar association with palaeoclimate. Overall this suggests that vivparity evolution cannot be separated from squamate lineage diversification. We suggest that parity mode transitions depend on environmental and intrinsic effects and that background diversification rate may be a factor in trait diversification more generally. 

Ultimately we need more genome-informed and mechanistic information about the basis of viviparity to better retrace its evolution, but these data are lacking.

success with NERC standard grant and soon hiring

 We were recently awarded a three year NERC grant to study the evolution and development of reproductive modes, with common lizards as a model organism

Check back early January if you are interested - we will be advertising for a postdoc soon!

Reproductive mode evolution and reversal demonstrate the genetic toolkits of egg-laying and live-bearing

Abstract: Laying eggs or giving birth to live young are two fundamentally different ways for females to produce their offspring. All birds, crocodilians, turtles, monotreme mammals (such as duck-billed platypus), and many lizards and snakes are egg-laying, as were most dinosaurs. In contrast, all placental mammals (like humans), marsupials, and some lizards and snakes are live-bearing. From studying embryos we know that many molecular and developmental aspects of these reproductive modes arose deep within the tree of life. For example, ancient egg-making structures are still retained within mammalian placenta, and the genes activated by pregnancy in lizards are the same as those activated by pregnancy in mammals and seahorses. Yet, clearly, substantial reproductive differences evolved between species; though it is not known how or why because the core genetic controls of these reproductive modes remain unknown. This major and obvious gap in our biological knowledge has persisted into the genomic era - where we can now study the entire DNA sequence of an organism - because we lacked an informative experimental model. Simply put, to test the genetic basis of traits that differ, the definitive experiment is to make a cross between the two different types. In the case of reproductive mode this is usual not possible, because species are too divergent to successfully breed. For example, no one can make a genetic cross of a platypus and a snake to test if the 'egg making DNA' is the same in both species. 

Our proposal seeks to shed light on the genetic basis of these fundamental reproductive traits using an exceptional species: the humbly-named 'common lizard'. 

To test long-standing ideas about the genetic basis of fundamental reproductive traits, we plan to do controlled functional studies of the different types found within these lizards and hybrid experimental crosses. By comparing the two lineages of egg-laying lizards we will be able to identify the genes necessary for egg-laying. This is due to the fact that the core genes should be found in the genomes of both and, if they are shared, these genes should be expressed in similar places and times. Mismatches will be evident and point to different bases. Then we will use computational approaches to reconstruct the phylogenetic tree of the 'egg-laying' (and 'live-bearing') genes across the history of the entire species and if oviparity evolved once or multiple times. This will reveal how changes in a species' DNA give rise to changes in reproductive mode. Because of the ancient origins and sharing of reproductive genes across species, the lessons learned from these lizards will provide new and valuable insights into the biology, reproductive health, and evolution of all vertebrates.

PI: Kathryn R Elmer (IBAHCM)

co-I Maureen Bain (IBAHCM-Vet School)

Project Parter: Jean Clobert (CNRS Moulis)

PhD opportunities for autumn 2021

 We have several PhD opportunities through competition in the IAPETUS programme. Please see Opportunities page

New paper: cryptic diversity in Chinese minnows

 from his time as a visiting PhD student in our lab group, Li Chao has published an excellent paper on cryptic diversity and its taxonomic implications. 

Cryptic species in White Cloud Mountain minnow, Tanichthys albonubes: Taxonomic and conservation implications

Molecular Phylogenetics and Evolution

https://doi.org/10.1016/j.ympev.2020.106950

Chao Li, Shuying Jiang. Kevin Schneider. Jinjin Jin, Hungdu Lin, JunjieWang, Kathryn R.Elmer, Jun Zhao

Abstract: Cryptic species describe two or more species that had mistakenly been considered to be a single species, a phenomenon that has been found throughout the tree of life. Recognizing cryptic species is key to estimating the real biodiversity of the world and understanding evolutionary processes. Molecular methods present an unprecedented opportunity for biologists to question whether morphologically similar populations are actually cryptic species. The minnow Tanichthys albonubes is a critically endangered freshwater fish and was classified as a second-class state-protected animal in China. Previous studies have revealed highly divergent lineages with similar morphological characters in this species. Herein, we tested for cryptic species across the ranges of all known wild populations of this minnow. Using multilocus molecular (one mitochondrial gene, two nuclear genes and 13 microsatellite loci) and morphological data for 230 individuals from eight populations, we found deep genetic divergence among these populations with subtle morphological disparity. Morphological examination found variance among these populations in the number of branched anal-fin rays. Based on genetic data, we inferred eight monophyletic groups that were well supported by haplotype network and population clustering analyses. Species delimitation methods suggested eight putative species in the T. albonubes complex. Molecular dating suggested that these cryptic species diverged in the period from the Pliocene to the Pleistocene. Based on these findings, we propose the existence of seven cryptic species in the T. albonubes complex. Our results highlight the need for a taxonomic revision of Tanichthys. What is more, the conservation status of and conservation strategies for the T. albonubes complex should be reassessed as soon as possible.

New paper: Intraspecific variation and structuring of phenotype in a lake-dwelling species are driven by lake size and elevation

 Research from now-FSBI PhD student Peter Koene, from his masters project in Glasgow - 

https://doi.org/10.1093/biolinnean/blaa137

Abstract

The fragmented, heterogeneous and relatively depauperate ecosystems of recently glaciated lakes present contrasting ecological opportunities for resident fish. Across a species, local adaptation may induce diverse and distinct phenotypic responses to various selection pressures. We tested for intraspecific phenotypic structuring by population in a common native lake-dwelling fish species across a medium-scale geographic region with considerable variation in lake types. We investigated potential lake-characteristic drivers of trophic morphology. Using geometric morphometric techniques, we quantified the head shapes of 759 adult brown trout (Salmo trutta L.) from 28 lakes and reservoirs across Scotland. Multivariate statistical analyses showed that almost all populations differed from one another. Trout from larger and deeper lakes had deeper, but shorter heads, and smaller eyes. Higher elevation lakes were associated with fish with shorter heads and jaws. Within-population shape variation also differed by population, and was positively correlated with lake surface area and depth. Trout within reservoirs differed subtly from those in natural lakes, having larger eyes, shorter jaws and greater variability. This study documents an extraordinary morphological variation between and within populations of brown trout, and demonstrates the role of the extrinsic environment in driving phenotypic structuring over a medium-scale and varied geographic area.

POSTDOC POSITION AVAILABLE

CLOSED 

Postdoc: UGlasgow.GenomicsReproductiveMode

We have a research opportunity open at the University of Glasgow's Institute of Biodiversity, Animal Health & Comparative Medicine (IBAHCM) working in the Evolutionary Analysis Group and the research team of Kathryn Elmer (http://www.gla.ac.uk/researchinstitutes/bahcm/staff/kathrynelmer/) in collaboration with Oscar Gaggiotti at University of St Andrews (https://risweb.st-andrews.ac.uk/portal/en/persons/oscar-eduardo-gaggiotti(43985656-390b-478e-b9a7-05fe88181e46).html_ The project is primarily based at Glasgow and research periods based at St Andrews are supported.

We are seeking a motivated, creative and enthusiastic postdoctoral researcher for a project on the genomic basis of oviparous and viviparous reproductive modes, funded by The Leverhulme Trust. This project will apply advanced statistical analyses to population-wide whole genome sequences to identify regions of the genome that show signals of response to selection, the molecular targets of that selection (genes, gene functions, and biological pathways), and genetic units fundamental to egg-laying vs live-bearing. The research model is the common lizard, which is a fascinating and unusual species because it is reproductively bimodal. 

A strong track record of genetic and evolutionary research is necessary, and on vertebrates is a benefit. Bioinformatic experience with NGS data and expertise in whole genome analysis is preferred. Skills in quantitative trait mapping, comparative genomics, ecological and/or population genomics, statistics, and phylogenetics are also valuable. Lab work and fieldwork skills are not strictly required but would be advantageous. Team working and positive attitude are a must. Candidates must have completed their PhD by the start of contract. International applicants will be eligible for a UK work visa. We welcome a diversity of applicants!

The position is for 3 years, with start date reasonably flexible. The position is open at grade 6 (early career postdoc) or grade 7 (experienced postdoc).

IBAHCM is a stimulating and interactive research environment with a wealth of opportunities for discussion, collaboration and cutting edge research in evolution, ecology, and disease. The University of Glasgow ranks in the world's top 100 universities.  The University and IBAHCM are both recognised with Athena SWAN awards. The city of Glasgow is lively and cultural, and sits on the doorstep of the great outdoors of the Scottish Highlands, islands, and coast.

The official job description and application requirements are available on the University of Glasgow homepage under current vacancies; http://www.gla.ac.uk/about/jobs/vacancies/ at job reference 039224

**The advertisement closes 7 August 2020.** 

Informal inquiries in advance are very welcome

New paper: Parallel evolution of Arctic charr across divergent lineages

"Parallelism in eco-morphology and gene expression despite variable evolutionary and genomic backgrounds in a Holarctic fish" is in press with PLoS Genetics. data available on Enlighten. 

https://doi.org/10.1371/journal.pgen.1008658

Abstract

Understanding the extent to which ecological divergence is repeatable is essential for predicting responses of biodiversity to environmental change. Here we test the predictability of evolution, from genotype to phenotype, by studying parallel evolution in a salmonid fish, Arctic charr (Salvelinus alpinus), across eleven replicate sympatric ecotype pairs (benthivorous-planktivorous and planktivorous-piscivorous) and two evolutionary lineages. We found considerable variability in eco-morphological divergence, with several traits related to foraging (eye diameter, pectoral fin length) being highly parallel even across lineages. This suggests repeated and predictable adaptation to environment. Consistent with ancestral genetic variation, hundreds of loci were associated with ecotype divergence within lineages of which eight were shared across lineages. This shared genetic variation was maintained despite variation in evolutionary histories, ranging from postglacial divergence in sympatry (ca. 10-15kya) to pre-glacial divergence (ca. 20-40kya) with postglacial secondary contact. Transcriptome-wide gene expression (44,102 genes) was highly parallel across replicates, involved biological processes characteristic of ecotype morphology and physiology, and revealed parallelism at the level of regulatory networks. This expression divergence was not only plastic but in part genetically controlled by parallel cis-eQTL. Lastly, we found that the magnitude of phenotypic divergence was largely correlated with the genetic differentiation and gene expression divergence. In contrast, the direction of phenotypic change was mostly determined by the interplay of adaptive genetic variation, gene expression, and ecosystem size. Ecosystem size further explained variation in putatively adaptive, ecotype-associated genomic patterns within and across lineages, highlighting the role of environmental variation and stochasticity in parallel evolution. Together, our findings demonstrate the parallel evolution of eco-morphology and gene expression within and across evolutionary lineages, which is controlled by the interplay of environmental stochasticity and evolutionary contingencies, largely overcoming variable evolutionary histories and genomic backgrounds.

New paper: Colour genes under selection in colourful salamanders

Burgon, J.D., Vieites, D.R., Jacobs, A., Weidt, S.K., Gunter, H.M., Steinfartz, S., Burgess, K., Mable, B.K. and Elmer, K.R., 2020. Functional colour genes and signals of selection in colour polymorphic salamanders. Molecular Ecology. in press online early

Led by PhD student James Burgon, this paper is a favourite! a project started with colleagues in Scotland, Germany and Spain, coming from plans that were long in the pipeline. A new set of colour candidate genes for amphibians.

Abstract

Colouration has been associated with multiple biologically relevant traits that drive adaptation and diversification in many taxa. However, despite the great diversity of colour patterns present in amphibians the underlying molecular basis is largely unknown. Here, we leverage insight from a highly colour‐variable lineage of the European fire salamander (Salamandra salamandra bernardezi) to identify functional associations with striking variation in colour morph and pattern. The three focal colour morphs—ancestral black‐yellow striped, fully yellow, and fully brown—differed in pattern, visible colouration, and cellular composition. From population genomic analyses of up to 4,702 loci, we found no correlations of neutral population genetic structure with colour morph. However we identified 21 loci with genotype‐phenotype associations, several of which relate to known colour genes. Further, we inferred response to selection at up to 142 loci between the colour morphs, again including several that relate to colouration genes. By transcriptomic analysis across all different combinations, we found 196 differentially expressed genes between yellow, brown, and black skin, 63 of which are candidate genes involved in animal colouration. The concordance across different statistical approaches and ‘omic datasets provide several lines of evidence for loci linked to functional differences between colour morphs, including TYR, CAMK1, and PMEL. We found little association between colour morph and the metabolomic profile of its toxic compounds from the skin secretions. Our research suggests that current ecological and evolutionary hypotheses for the origins and maintenance of these striking colour morphs may need to be revisited.

New paper: endemic fish diversity swamped by stocking

Work from Li Chao's research visit with us:
Li, C., Wang, J., Chen, J., Schneider, K., Veettil, R.K., Elmer, K.R. and Zhao, J., 2020. Native bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix populations in the Pearl River are threatened by Yangtze River introductions as revealed by mitochondrial DNA. Journal of Fish Biology. in press online early

Culturally and economically important fishes with conservation challenges due to people stocking fry and building dams.

Abstract
Bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix have been two economically important aquaculture species in China for centuries. In the past decades, bighead and silver carp have been introduced from the Yangtze River to many river systems in China, including the Pearl River, in annual, large‐scale, stocking activities to enhance wild fisheries. Nonetheless, few studies have assessed the ecological or genetic impacts of such introductions on native conspecific fish populations. An mtDNA D‐loop segment of 978 bp from 213 bighead carp samples from 9 populations and a 975 bp segment from 204 silver carp samples from 10 populations were obtained to evaluate genetic diversity and population integrity. Results from a haplotype network analysis revealed that most haplotypes of the Pearl River clustered with those of Yangtze River origin and only a small proportion were distinct, suggesting that both the native Pearl River bighead and silver carp populations are currently dominated by genetic material from the Yangtze River. The genetic diversity of Pearl River populations is high in both species because of this inter‐population gene flow, but the diversity of native Pearl River populations is low. To preserve the native genetic diversity, stocking of non‐native fingerlings should cease immediately and native Pearl River bighead and silver carp fish farms should be established. This research demonstrates the danger to native biodiversity across China because of the substantial, ongoing stock‐enhancement activities without prior genetic assessment.

New paper: convergence in molecular signals of selection across genera

Paper led by PhD Student Kevin Schneider analysed all available transcriptome data for salmonids, to ask: at the molecular evolution level, what is similar about rapidly diversifying lake salmonids?

Schneider, K., Adams, C.E. and Elmer, K.R., 2019. Parallel selection on ecologically relevant gene functions in the transcriptomes of highly diversifying salmonids. BMC genomics, 20(1), pp.1-23.

open access paper available here

Abstract
Background
Salmonid fishes are characterised by a very high level of variation in trophic, ecological, physiological, and life history adaptations. Some salmonid taxa show exceptional potential for fast, within-lake diversification into morphologically and ecologically distinct variants, often in parallel; these are the lake-resident charr and whitefish (several species in the genera Salvelinus and Coregonus). To identify selection on genes and gene categories associated with such predictable diversifications, we analysed 2702 orthogroups (4.82 Mbp total; average 4.77 genes/orthogroup; average 1783 bp/orthogroup). We did so in two charr and two whitefish species and compared to five other salmonid lineages, which do not evolve in such ecologically predictable ways, and one non-salmonid outgroup.

Results
All selection analyses are based on Coregonus and Salvelinus compared to non-diversifying taxa. We found more orthogroups were affected by relaxed selection than intensified selection. Of those, 122 were under significant relaxed selection, with trends of an overrepresentation of serine family amino acid metabolism and transcriptional regulation, and significant enrichment of behaviour-associated gene functions. Seventy-eight orthogroups were under significant intensified selection and were enriched for signalling process and transcriptional regulation gene ontology terms and actin filament and lipid metabolism gene sets. Ninety-two orthogroups were under diversifying/positive selection. These were enriched for signal transduction, transmembrane transport, and pyruvate metabolism gene ontology terms and often contained genes involved in transcriptional regulation and development. Several orthogroups showed signs of multiple types of selection. For example, orthogroups under relaxed and diversifying selection contained genes such as ap1m2, involved in immunity and development, and slc6a8, playing an important role in muscle and brain creatine uptake. Orthogroups under intensified and diversifying selection were also found, such as genes syn3, with a role in neural processes, and ctsk, involved in bone remodelling.

Conclusions
Our approach pinpointed relevant genomic targets by distinguishing among different kinds of selection. We found that relaxed, intensified, and diversifying selection affect orthogroups and gene functions of ecological relevance in salmonids. Because they were found consistently and robustly across charr and whitefish and not other salmonid lineages, we propose these genes have a potential role in the replicated ecological diversifications.

New paper: telomere lengths differ between parity modes

We have a new collaborative paper out with Pat Monaghan and the telomeres lab. The dynamics of telomeres in lizards are really poorly understood. Here we brought together an evolutionary perspective, genetic and pedigree information, and an analysis of telomeres. Also cover image, a beautiful oviparous female and her clutch.

McLennan, D., Recknagel, H., Elmer, K.R. and Monaghan, P., 2019. Distinct telomere differences within a reproductively bimodal common lizard population. Functional Ecology, 33(10), pp.1917-1927.

Open access full article here 

ABSTRACT
Different strategies of reproductive mode, either oviparity (egg‐laying) or viviparity (live‐bearing), will be associated with a range of other life‐history differences that are expected to affect patterns of ageing and longevity. It is usually difficult to compare the effects of alternative reproductive modes because of evolutionary and ecological divergence. However, the very rare exemplars of reproductive bimodality, in which different modes exist within a single species, offer an opportunity for robust and controlled comparisons.One trait of interest that could be associated with life history, ageing and longevity is the length of the telomeres, which form protective caps at the chromosome ends and are generally considered a good indicator of cellular health. The shortening of these telomeres has been linked to stressful conditions; therefore, it is possible that differing reproductive costs will influence patterns of telomere loss. This is important because a number of studies have linked a shorter telomere length to reduced survival. Here, we have studied maternal and offspring telomere dynamics in the common lizard (Zootoca vivipara). Our study has focused on a population where oviparous and viviparous individuals co‐occur in the same habitat and occasionally interbreed to form admixed individuals. While viviparity confers many advantages for offspring, it might also incur substantial costs for the mother, for example require more energy. Therefore, we predicted that viviparous mothers would have relatively shorter telomeres than oviparous mothers, with admixed mothers having intermediate telomere lengths. There is thought to be a heritable component to telomere length; therefore, we also hypothesized that offspring would follow the same pattern as the mothers. Contrary to our predictions, the viviparous mothers and offspring had the longest telomeres, and the oviparous mothers and offspring had the shortest telomeres. The differing telomere lengths may have evolved as an effect of the life‐history divergence between the reproductive modes, for example due to the increased growth rate that viviparous individuals may undergo to reach a similar size at reproduction.

fully funded PhD position available in charr population genomics

A competitive fully-funded PhD studentship is be available to studyadaptation and population genomics of Scotland's most variable fishthe Arctic charr -- with Colin Adams and Kathryn Elmer at the Universityof Glasgow, Scotland. We are looking for an enthusiastic evolutionarybiologist to join our team!
Project: The lake-dwelling salmonid fish, the Arctic charr (Salvelinusalpinus) is highly diverse both in phenotype and genotype. This takesthe form of substantial variation within and between lakes; in someplaces the latter being expressed as eco-morphologically distinctand reproductively isolated sympatric polymorphisms. In addition thespecies is of high conservation value in the UK. This project willuse high-resolution population genomic techniques to resolve questionsabout the phylogenetic similarities between allopatric and sympatricpopulations to inform the taxonomic position of the species and to helpidentify units that may require conservation protection. Samples from a wide range of populations from across Scotland andoutgroups are already available, and there may be the opportunity tocollect more.
The project is supported in part by Scottish Natural Heritage and theoutcomes of this PhD will have direct relevance for national freshwaterconservation and management.
Funding: The project is fully funded for 3 years: stipend (salary)of pounds 14,500 per year, university fees at UK/EU rate, and consumablescosts. **Anyone from the EU/UK is eligible for the full funding**

The successful candidate for this project is likely to be someone with astrong theoretical background in evolution and/or population genetics andwho can show evidence of practical laboratory and analytical experiencein an appropriate field.

You will join a collegial and motivated research team with PhDstudents, postdocs and technician support studying evolution andadaptation in natural environments, especially with a focus on fishesand herps. Prof. Adams studies fish biology and trophic ecology and isDirector of the Scottish Centre for Ecology and the Natural Environment(SCENE) on Loch Lomond. Dr. Elmer is interested in the genetics ofbiodiversity and ecological diversification and based in the EvolutionaryAnalysis Group. Both faculty are in the Institute of Biodiversity,Animal Health & Comparative Medicine, which is part of the College ofMedical, Veterinary and Life Sciences at the University of Glasgow,Scotland. You can find more about our activities and interests here:https://www.gla.ac.uk/researchinstitutes/bahcm/staff/kathrynelmer/http://elmerlab.blogspot.comhttps://www.gla.ac.uk/researchinstitutes/bahcm/staff/colinadams/ 
The project is also co-supervised by Colin Bean (Scottish Natural Heritage)and will work closely with collaborators in Ireland (P. Prodohl) The University of Glasgow ranks in the world's top 100 universities andIBAHCM is an outstanding research institution with many opportunitiesfor collaboration and discussion in a supportive and productiveenvironment. Glasgow is a lively cultural city on the doorstep of thebeautifully rugged Scottish Highlands.

Deadline for applications is 14 August 2019All applications must be made through the website strictly by the deadline.

start date 1 Oct 2019

Please find more details and the application herehttps://www.findaphd.com/phds/project/the-adaptive-diversity-of-arctic-charr-salvelinus-alpinus-in-scotland/?p110955

Informal inquiries to Kathryn Elmer or Colin Adams in advance of the deadline are welcome.