Divergence/Vicariance: not completely convinced

And the moment to say something about biogeography came!

What could I say??? I think it is because of the school that I had as undergraduate, I cannot say things from which I'm not completely certain/convinced and I need to have arguments to defend what I'm saying.

Biogeographic History of Apodrosus looks to me as too pretentious:

- I'm not sure if we (I?) now know ALL Apodrosus species and how extensive the distributions are. Several species are represented by individuals collected at the same and unique event.

- I was impeded to talk about Bio-geography also because I don't really know about the ecological requirements and limitations for each species; I only know about Puerto Rican species because I've been here collecting them and I now know where I can found which one (there are only 3).

- Now History? please! I don't have (yet) the Caribbean geologic history in my head to try to explain diversification patterns within and among islands... At last, i was in psychological negation to use such a sumptuous title.

Well, what I do know and what I can handle without feel I'm promising too much?

- I have 13 recognizable (and named jejeje) species.

- I have distribution data for all the specimens, that can be traced on a map.

My advisor (Dr. Nico Franz - UPRM) gave me a useful and simple guide of how to do a Divergence-Vicariance analysis without too much to think. At first I just thought "ok, let's do what he said", but the more I advanced in the exercise, the more sense it acquired.

First, for the 20 species I had 17 areas of distribution: the analyses didn't run!

The next logical (?) step was to reduce the number of areas by fusing sectors: I had then 8 areas of distribution that results in 9 dispersion events BUT, not always the sequence of the "dispersion" had a "simple" explanation (which I could handle without thinking in vicariance and extinction). So, fuse areas again!

At the third attempt I had 5 areas (which couldn't be amalgamated in a merely geographic sense without appear arbitrary). The analysis resulted in 5 dispersion events, that are understandable without too much history involved (overall taking into account I had no time to learn about Caribbean geological history at that moment).

This is an image of the results:

- A map (courtesy of Google maps) with the five defined areas :

- Central America - Hispaniola - Puerto Rico

- The Turks and Caicos Islands - The Bahamas

- A taxon/area cladogram in which the branches correspond to species and colors to areas.

- An area cladogram without geological time incorporated, just to show the dispersions.

If we incorporate geological history, the cladogram will tell if the current distribution is explained for vicariance, dispersals, extinctions... that would be really informative!