One of the things that we investigate when we look at these things is variation in the color pattern of an individual species. And there is very little variation. As a strategy, if you were going to have a color pattern that is uniformly recognized by predators who try to feed on you, Then natural selection is going to select out variants from that general color pattern. So you would expect them to have fairly uniform color patterns for each species. This is one of the things that you commonly find. The major color pattern differences that you see between these individuals are characteristic for the entire species. So this is what the sister species of ghiselini looks like. This is called lapislazuli and it's found only in the Galapagos Islands.

Now, the sister species of those two also has a very similar color pattern and a dark blue color with bright yellow spots. Then if we go one node lower in that evolutionary tree and look at the sister species to all three, it has this color pattern. So we then try to go one node lower and say, "What does the color pattern of the sister species to the four look like?" We don't have a good enough resolution in the phylogeny but we know that it has to be one of those species that's found in the Atlantic. And all of the ones in the Atlantic, as indicated in the slide that you saw, those three species in the Strait of Gibraltar, have a light blue color pattern.

This suggests to us that the most plausible explanation of the evolution of the color pattern in this eastern Pacific subclade of this genus is that the common ancestor of them had dark blue pigment with yellow spots. And obviously there are other variations in the color patterns. The fact that this one has interrupted bands, those are differences between those individual members of that clade but that the most possible explanation of their color patterns, their general color pattern is that their common ancestor had all of those color pattern attributes rather than each one of them evolving independently.

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