Adaptation in Alien Species
The small population size of these populations should limit their adaptive potential. However, lizards of both French and Italian origin have taken a small step towards viviparity since their introduction to England. This reduces the time needed to complete embryogenesis in the nest. Non-native embryos also develop faster at low temperature than native embryos. These adaptive responses allow lizards to hatch before autumn despite the cool soil temperature in England, and help populations persist north of their natural range.
The evolution of prolonged egg retention and faster developmental rate in non-native populations of both French and Italian origin provide opportunities to study the developmental basis of convergent evolution. By profiling gene expression in early embryos, we have revealed that populations of French and Italian origin have recruited different genes to speed up development, but that the function of these genes are broadly similar. We are now interested in asking what the underlying mechanisms are, if these are similar to those underlying climatic adaptation during natural range expansion, and if maternal effects can facilitate rapid adaptation.
If you want to know more
Feiner, N., Rago, A., While, G.M. & Uller, T. 2017. Signatures of selection in embryonic transcriptomes of lizards adapting in parallel to cool climate. Evolution, in press DOI: 10.1111/evo.13397
Michaelides, S., While, G.M., Zajac, N., Aubret, F., Calsbeek, B., Sacchi, R., Zuffi, M.A.L. & Uller, T. 2016. Loss of genetic diversity and increased embryonic mortality in non-native lizards. Molecular Ecology 15: 4113–4125
While, G.M., Williamson, J., Prescott, G., Horvathova, T., Fresnillo, B., Beeton, N.J., Halliwell, B., Michaelides, S. & Uller, T. 2015. Adaptive responses to cool climate promotes persistence of a non-native lizard. Proceedings of the Royal Society of London B 282: 20142638
Michaelides, S., While, G.M., Zajac, N. & Uller, T. 2015. Widespread primary, but geographically restricted secondary, human introductions of wall lizards, Podarcis muralis. Molecular Ecology 24: 2702-2717