Article View: sci.bio
Article #2789Re: Brainsize - the great brain race
From: w.p.coyne
Date: Tue, 05 Jan 1993 16:01
Date: Tue, 05 Jan 1993 16:01
23 lines
1524 bytes
1524 bytes
Another bit of trivial but possibly interesting information from the
article, which I forgot to include, so I'm doing it now, is:-
WhY did brain size remain unchanging for 150 million years?
Mammal brain size barely changed between 200Ma (when mammals evolved)
until 65 Ma. Why?
A possible answer comes from some studies conducted on modern birds.
It was found that songbirds which stored food had a much bigger
hippocampus than in non-storers. Birds most active at twilight have
larger olfactory bulbs than other species.
The strange thing is that for all these birds the total brain
size is about the same. Enlargement of one area is always accompanied
by a reduction in size of one or more other areas. This indicates that
there might be constraints on total size.
Whatever the solution of this is, it might explain why entire classes
of animals have approximately the same brain size. It would then raise
the importance of those special times (200 Ma and 65 Ma for mammals and
2.5Ma for humans) during which groups of species broke out of their
contraints on brain size.
Technical Details
Message-ID:
<C0E1tq.14w@newcastle.ac.uk>Path:
arc1-ca.pugleaf.net!sparky!uunet!pipex!bnr.co.uk!uknet!newcastle.ac.uk!newsShow Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!sparky!uunet!pipex!bnr.co.uk!uknet!newcastle.ac.uk!news From: w.p.coyne@newcastle.ac.uk Newsgroups: sci.bio Subject: Re: Brainsize - the great brain race Message-ID: <C0E1tq.14w@newcastle.ac.uk> Date: 5 Jan 93 16:01:02 GMT Reply-To: w.p.coyne@newcastle.ac.uk Organization: Chemical & Process Engineering Dept, University of Newcastle, UK. Lines: 23 Nntp-Posting-Host: erui