Evolution on Repeat
Naturalists that travelled the Mediterranean in the 19th century were struck by the wall lizards‘ color patterns, which seemingly varied without any geographic structure. We are still trying to map this “chaos of variation”, but it is now clear that one reason for the confusion is that the same phenotypes have evolved again and again.
One example is the so-called ‘nigriventris syndrome’: large, stout and aggressive lizards with striking green backs, large blue spots on their flanks and black bellies. In the common wall lizards, we have uncovered the origin of this syndrome and followed its introgressive spread, and we are currently expanding this research into two main directions. One is taking a comparative approach to study similarities in the evolution of the syndrome across species, and the other is a developmental approach trying to understand why colour, morphology and behaviour co-evolve.
If you want to know more:
Feiner, N., Yang, W., Bunikis, I., While, G.M. & Uller, T. 2024. Adaptive introgression reveals the genetic basis of a sexually selected syndrome in wall lizards. Science Advances 10:14
Yang, W., Feiner, N., Pinho, C., While, G.M., Kaliontzopoulou, A., Harris, D.J., Salvi, D. & Uller, T. 2021. Extensive introgression and mosaic genomes of Mediterranean endemic lizards. Nature Communications 12:2762
Ruiz Miñano, M., While, G.M., Yang, W., Burridge, C.P., Sacchi, R., Zuffi, M., Scali, R., Salvi, D., Uller, T. 2021. Climate shapes the geographic distribution and introgressive spread of colour ornamentation in common wall lizards. The American Naturalist 198:379-393
Yang, W., Feiner, N., Laakkonen, H., Sacchi, R., Zuffi, M.A.L., Scali, S., While, G.M., Uller, T. 2020. Spatial variation in gene flow across a hybrid zone reveals causes of reproductive isolation and asymmetric introgression in wall lizards. Evolution 74:1289-1300