My name is Adriana Briscoe,
and I'm a professor in
the Department of Ecology and Evolutionary Biology
at the University of California, Irvine.
I'm going to be talking to you today about an evolutionary case-study:
the genomics of speciation in Heliconius butterflies.
Before I do that, I'm going to say a word about the work we study in my lab.
We're interested in the evolution of color vision and coloration in butterflies.
You're going to hear a lot more about coloration in butterflies, as
this topic has proven to be a model system for studies of speciation.
Before we get to that, here are images of butterfly eyeshine
which illustrate the diverse coloration in living butterfly eyes.
It's worth noting that coloration on butterfly wings evolved as the result of
both natural and sexual selection, mediated by
both visual predators (such as birds) and by the butterflies themselves.
Heliconius butterflies illustrate both of these principles.
These butterflies are found in the tropics, and they played an important role
in supporting Charles Darwin's theory of evolution by natural selection.
Specifically, natural historians like Fritz Müller
(who collected and described butterflies in Brazil in the 1800s)
recognized that the bright coloration of the wings of Heliconius butterflies
functioned as a signal to birds that these butterflies are unpalatable.
As a consequence of birds learning to associate these color patterns with a bad taste,
unrelated species of butterflies living in
the same geographical locality evolved similar wing patterns.
This kind of mimicry is known today as 'Müllerian mimicry'.
An important aspect of Heliconius biology is that different species of