Well, in some cases, by knowing again something about the phylogenetic relationships of organisms that are found in the same place, we can look at how different components of their color patterns may have evolved. These are three different species of nudibranchs that were found within a few meters of each other in one dive site in the Philippines. The two that are more closely related to each other than to the third are these two species here, although this species and this species certainly have greater similarities in terms of their color patterns of having a sort of purplish body with opaque white and dark spots. One of the things that you notice between these two species is that they have three broad color bands whereas this third species has a whole series of white lines. Although these appear more similar to the eye, there are certain evolutionary components of the color pattern that these two have derived from their common ancestor. These are sister species of each other and the third is in fact a member of that genus Hypselodoris that we've been looking at for much of the rest of the time.

So, basically by knowing something about the environment in which these organisms live, the fact that they are all sympatric together, living in a very similar microhabitat provides important context for understanding the importance of their color patterns. Certain components, again, being these three stripes, are inherited from the common ancestor. The similarities here are due to convergent evolution. So we can piece together some fairly interesting evolutionary stories about how these different color patterns came into being and how they persist or are modified.

I wanted to show you another group that I'm working on with my other graduate student Shireen Fahey. This is a group of organisms that is characterized by having a series of brightly colored ridges on their body's surface. We find that there is tremendous variation in the kinds of color patterns that you see in members of this group. Some of them are incredibly complex and elaborate. And then there is a group that has a series of sort of rounded tubercles, little bumps, with orange spots. All of the members of this group have black spots on the chemosensory organs and on the gills. Another representative, does not have the orange lines between the tubercles but otherwise their color patterns are very similar.

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