Posted by:
cychluraguy
at Thu Jan 21 09:52:06 2010 [ Email Message ] [ Show All Posts by cychluraguy ]
Last night I spent a coupple hours reading about about the geologic history of the carribean and it is pretty interesting. There is more than one theory on this subject mostly about whether cuba was attached to the yucatan or not. This would seem like a possible land bridge from central america except that it was something like 80 million years ago and most of the animals in the carribean are not that old. jamaca has been underwater several times and since it has been above this time around it has had no land bridges to any other islands. Hispanola and puerto rico were once attached and hispanola has been cut in half several times (this could be why it has 2 different cycluras on it?) The lesser antillies has never had a land bridge and most of the islands have never been attached. This seems to be the main reason the carribean has so few mamals because they would have crossed land bridges as well if they were there. Alot of people think that islands have had animals evolve on them and then go extinct amd then have new animals arrive and start evolving again, this could be why there are such variations in cyclura. The bahamas was never attached and it was the last to be colonized and has varied in size alot based on sea levals. Ricordi are probobly the oldest of the cyclura and cyclura could be as much as 30 million years old. Given the close relation of the cychluras in the bahamas and the cuban iguanas the GC and the LC must arrived on there island fairly recently and there has been no land bridges from them to cuba in a least 20 million years so it does seem likely that they would have had to raft there. If the bahamas iguanas were rafted and the jamacan iguana rafted it must have been alot longer time ago than the GC or the LC due to the greater genetic divergence from the animals that founded them. It is interesting to think that there could have been long extinct species of cyclura that were unlike any we have today on these islands that have been recolonized by the modern cyclura we have today.
This is kind of a compelation of info I found and is not necessarly 100% agreed apon.
Rob
[ Hide Replies ]
|
RE: Blue Cyclura Theory - cychluraguy, Thu Jan 21 09:52:06 2010