How lizards conquered the world: Three genomic case studies on adaptation and speciation
Name of applicant
Morten Allentoft
Institution
University of Copenhagen
Amount
DKK 4,186,052
Year
2019
Type of grant
Semper Ardens: Accelerate
What?
Lizards! I am an evolutionary biologist and have always been fascinated by reptiles, so this project is a perfect combination of research and hobby. Using powerful DNA sequencing technology, we aim to study hundreds of lizard genomes across three climate zones, to obtain new information on speciation processes. How did highly temperature-sensitive sand lizards adapt to a cold life in Northern Denmark? Why have a population of wall lizards in Croatia evolved different head shapes over just 50 years? Why do we observe a tremendous diversity of peculiar pygmy chameleons in the Eastern Arc Mountains in Tanzania? By answering these evolutionary riddles, we can obtain knowledge on the basic mechanisms that control the formation and distribution of biodiversity on our planet.
Why?
By identifying genetic differences in populations adapted to different environmental conditions, it is possible to pinpoint mutations responsible for the adaptations. This can provide basic new knowledge on natural selection processes and the evolutionary impacts of, for example, ongoing climate changes. This seems particularly pertinent for ectothermic animals like reptiles, whose metabolic processes are highly affected by ambient temperature. Therefore, by studying speciation processes and adaptions to a changing climate and diet, we will be addressing some of the most central and timely themes in evolutionary biology. Moreover, this work will bring attention to an understudied group or organisms that is declining at a global scale.
How?
Because evolutionary forces are expressed as changes in the genetic code over time, large scale genomic data sets are ideal for obtaining detailed insight into speciation processes. But the first step is always to collect tissue samples – in this case we will sample both animals in the wild and museum specimens. This is the fun part that for example involves climbing steep slopes in East African montane rainforests at night to search for chameleons! Next, we will extract the DNA in the lab and use Next Generation Sequencing to assemble complete genomes of many individuals from the species in question. We can then use powerful computers to compare genomes from different species or populations, thereby identifying the exact genes or regions that carry the marks of evolutionary change.