[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: bauplan convergence



Rob Gay wrote:
>
> So the question is, what drove this to happen in birds and not in the other
> tree-dwelling predators? 
> ... SNIP

Don't always look for nice neat logical answers. Sometimes things aren't
"driven" at all. Plain old dumb luck can play a major role in the
evolutionary process. 

Didn't I read somewhere that the gene that allows some humans to
tolerate lactose was once a gene for doing something completely
different? If so, then of all the random mutations that could have had
little effect on the original gene, or which could have rendered the
gene useless, one just happened to occur that turned it into something
different AND useful. Now humans can tolerate high levels of lactose
into adulthood, and therefore use the milk of other species as a food
source.

I've pretty much given up speculating on the origin of bird flight.
There are just too many possible variables and too little direct
evidence. You might as well ask how turtles developed shells: it
requires the scapulae to somehow end up on the inside of the rib cage.
How the heck did that ever happen? Sometimes I think logic is entirely
the wrong approach to studying evolution.

-- 
____________________________________________
        Dann Pigdon
        GIS Archaeologist
        Melbourne, Australia

        Australian Dinosaurs:
        http://home.alphalink.com.au/~dannj
        http://www.geocities.com/dannj.geo
____________________________________________