Research

Genomics and Speciation

The diversity of life on our planet is generated by the process of speciation, the splitting of a population into two divergent groups that can coexist in a state of nature. What changes at the genomic level cause speciation are still obscure. This is a time to jettison preconceived ideas, and to absorb what new data can tell us.

Today, these data will frequently include whole genome sequences. Heliconius melpomene is the first butterfly species to have had its genome both sequenced and mapped to chromosomes...
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Natural selection, mimicry and speciation

Heliconius are famous for the extraordinary diversity of colour patterns within and between species. All of the heliconiine and ithomiine species are distasteful to predators, and their bright "aposematic" coloration is used to warn enemies. I have long been interested in mimicry, and newer genomics work is at last leading to an understanding of the regulatory genetic switches involved in mimicry. ...
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Hybridization and introgression

Many species hybridize with other species, and this can lead to wholesale transfer of variation important in adaptive evolution. In some cases, this sudden acquisition of recombined adaptive traits can lead to the origins of new species, or "hybrid speciation." Our group, working with Heliconius, ithomiines, and other insects, has been at the forefront of this recent research. ...
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Species concepts and the Taxome Project

The newer understanding we have reached about the genomic nature of species and hybridization is leading to a re-examination of what we mean by the term "species." For instance, the argument that species are "reproductively isolated" seems to lose its power when over 40% of the genome has undergone admixture between the sympatric pair Heliconius cydno and Heliconius melpomene. ...
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History of science

Interest in hybridization and revised species concepts led to a fascination with why others had held different views in the past ...
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