Re: [Gecko] interspecific breeding

[Racodactylus]

Several factors contribute to prevention of hybrids in nature.

The most notable are the "prezygotic" reproductive isolating mechainisms.  These include geographical (potential mates are isolated by geographic boundries), ecological (potential mates occupy different habitats-- terriestrial vs. arboreal), behavoral (potential mates find each other, but have no clue what to do), and mechainical (the reproductive organs differ in a way that makes fertilization impossible-- like  Spharoedactylus male attempting to mate with a Rhacodactylus leachianus female).

There are also "post zygotic" mechainisms as well.  Gameate fatality normally occurs after a sucessful mating.  An embryoe might manage to develope, but at a certain stage it can no longer survive.  The chromosomal differences are dramtic later stages in development where distinguishing, and conflicting, features begin to develope.  For instance, a human embryoe a lizard embryoe look very similar at early stages, and then distinguish themselves.  If a hyrbid manages to completely develope, more often than not they lack the fitness needed to survive.  Unable to compete, they die.  They are also normally infertile, so do not manage to reproduce.  Sometimes, they are parthenogenetic, which means they can reproduce and start populations.  However, parthenogenesis has dire effects on the continued existance of the species.

This isn't always the case.  Hybrids have the potential to get the best genes from both parents.  If Lepidodactylus did indeed develope from the interspecific breeding of L. moestus and a species awaiting description, then L. lugubris is a excellent example of this.  They are more mite resistant than their parents, and have colonized just about every tropical location I can think off.  How often is L. moestus encountered?  Or the L. ssp?

Parthenogenesis prohibits animals from adapting to changing enviroments because it lacks the potential to sufficiently mutate.  If the enviroment changes, they die.  Makes you wonder how many parthenogenetic geckoes there have been.

I'm not aware of any Uroplatus hybrids, but there are some in Rhacodactylus.  R. chaohoua has been crossed with R. cilliatus.  I think they look pretty cool.

--Daniel