Re: Two new FAQs: Everything You Wanted To Know About Cladistics

[Mike Taylor <mike@tecc.co.uk>]

People,

Pat Norton raised an interesting point on my ``cladistics dumbed
down'' FAQ:

> Date: Wed, 22 Aug 2001 13:17:23 -0400
> From: "" <ptnorton@msn.com>
> 
> First, isn't it true that a fourth tree (shown below) could be added
> to your example?
> 
>      A  B  C
>       \ | /
>        \|/
> 
> This certainly wouldn't affect your conclusion of the most
> parsimonious tree, but it seems to be as viable an option for review
> as the other three and it wasn't obvious to me why it was excluded.

On mature reflection, it's not obvious to me either :-)

Could someone please briefly explain why we avoid polychotomies?  Is
the truthful answer just that life is easier if we don't bother
thinking about them?  :-)

BTW., I was expecting a flood of emails explaining why my trivial
"worked example" with _Apatosaurus_, _Brachiosaurus_ and
_Camarasaurus_ is nonsense -- but, to my surprise, no-one seems to
have criticised that bit yet.  Have I got away with it?

Thanks,

 _/|_    _______________________________________________________________
/o ) \/  Mike Taylor | <mike@miketaylor.org.uk> | www.miketaylor.org.uk
)_v__/\  "Don't give me that, you snotty-faced heap of parrot
         droppings" -- Monty Python.