Arlin Stoltzfus wrote:
> > (b) It readily explains why certain characteristics of
> > eukaryotic cells (e.g. components of transcription and
> > translation machinery) are similar to archaebacteria, while
> > others are clearly derived from eubacteria (e.g. ester-
> > linked straight chain membrane lipids, fatty acid
> > synthetase)
>> This pattern does favor a chimaeric model over any other model.
^
NOT
Oops! Please insert the "NOT" above for the intended meaning.
Archaebacterial membrane composition may be a derived condition,
and requires only one event regardless of the tree topology (so
long as archaebacteria are holophyletic); the similarity
of archaebacterial and eukaryotic transcription machinery could
be ancestral regardless of the tree [and could also be a derived
state in the conventional ( eub ( archae, euk ) ) tree]. Where
is the evidence for 'fusion'? How does this contradict simple
common ancestry? If we find that fungi share some features with
plants and others with animals, should we suddenly start questioning
the idea that they are related by a bifurcating tree and start
proposing fusions?
Arlin
--
Arlin Stoltzfus
Department of Biochemistry
Dalhousie University
Halifax, Nova Scotia B3H 4H7 CANADA
(email) arlin at is.dal.ca
(phone) 902-494-3569
(fax) 902-494-1355
