Re: Genetic Study Shows Snake Evolution

[Michael Habib <mbh3q@virginia.edu>]

I could be wrong, as I am hardly an expert in lizard systematics, but it
seems like the really strange thing about the tree is not the position of
the Serpentes, but the position of Iguania (stuck there into
Scleroglossans).  Thoughts?

--Mike Habib

On 2/4/04 3:06 PM, "David Marjanovic" <david.marjanovic@gmx.at> wrote:

>> "Our results (figure 1)
> 
> This is a sort of consensus tree, if I've understood it, of maximum
> likelihood, maximum parsimony, minimum evolution (isn't that a kind of
> maximum likelihood?) and Bayesian methods. Simplified here:
> 
> +--turtle
> `--+--tuatara
>  `--Squamata
>       |--Dibamidae
>       `--+--Gekkonidae
>          `--+--+--Cordylidae
>             |  `--+--Xantusiidae
>             |     `--Scincidae
>             `--+--+--+--Teiidae
>                |  |  `--Gymnophthalmidae
>                |  `--+--+--Lacertidae
>                |     |  `--Rhineuridae
>                |     `--+--Bipedidae
>                |       `--+--Amphisbaenidae
>                |          `--Trogonophidae
>                `--+--Anguimorpha
>                   |    |--+--Xenosauridae
>                   |    |  `--Varanidae
>                   |    `--+--Helodermatidae
>                   |       `--Anguidae
>                   `--+--Iguania
>                      |    |--Iguanidae
>                      |    `--+--Chamaeleonidae
>                      |       `--Agamidae
>                      `--Serpentes
>                           |--Scolecophidia
>                           `--Alethinophidia
> 
> The topology within snakes looks rather normal -- according to what little I
> know about snake phylogeny. (Iguania + Serpentes) has a bootstrap value from
> maximum parsimony of 59 and a Bayesian posterior probability of 50. The only
> big clades that have both values at 100 are Squamata and Serpentes. The
> basal 3 nodes within Squamata have very low values. In short... don't trust
> that tree. :-)
>