Thanks Kayla- nice coverage of character displacement.

I'd like to add one thing to that too:
Schluter focuses a lot on character displacement between closely related taxa...
However, character displacement can occur between distantly related taxa as well, it just seems to be less studied. For example, certainly the presence of other competing lizards NOT closely related to Sceloporus undulatus in New Mexico will cause them to use a smaller portion of their available resources.

Consider S. undulatus in surrounding dark soils habitat; there are several other competing lizards (such as Uta stansburiana pictured above), that may reduce the available niche space for Sceloporus. There are several potentially competing lizard species in the dark soils surrounding White Sands... but in White Sands itself, there are only three lizard species. Does this then mean that Sceloporus (and other White Sands inhabitants) are able to use a greater proportion of their habitat than members of their ancestral populations in dark soils? In other words, is something... the opposite... of character displacement occurring in White Sands?

We'll talk more about ecological opportunity and ecological release next week.

And I'm burnt out so... perhaps a little more later.