Monday, December 7, 2015

SPONGE (Porifera) ORIGIN

Related Posts

The topic was briefly addressed in the post on April 26, 2015.  A bit about it can be found in posts on June 17 and June 20 in 2013.  More general approach to the topic may be elsewhere but the citation of research critical to placing the sponges in the evolutionary sequence depends heavily upon Kazmierczak, 1984, cited in the July 18, 2013 post.

Neglected research

An otherwise outstanding 2004 paper in Invertebrate Biology, does not agree with the position I take.  Manuel Maldonado, in his paper "Choanoflagellates, choanocytes, and animal multicellularity", pages 1-22 in volume 123, reviews and analyzes an extensive literature but does not include Kazmierczak's report.  A similar comment could be made for the paper that follows, Antonio C. Marques and Allen G. Collins, "Cladistic analysis of Medusozoa and cnidarian evolution", pages 23-42 of the same issue.   They also are handicapped by omitting the Kazmierczak report.

I had the issue on top of a small pile or journals I had retained but not examined very thoroughly.  More concern about it would be appropriate if my peers did not all seem to be misled by not realizing the error in molecular phylogeny noted in my post of May 31, 2013.  Until they recognize that I will not be too concerned about what they have to say.

A note about family trees

Common ancestry could be determined by taking a phylogeny and treating it as a branching string.  By anchoring the most reasonable earliest ancestor and pulling up on the two more recent groups of interest, the most recent common ancestor is where the two lines join.  All others that are not ancestral to those groups will be hanging loosely.  Just as in a computer program to determine relationships, it gives an answer that might change greatly with new information taken into consideration.

The best results will eventually be obtained by combining molecular and classical biology in many cases.

Joseph G. Engemann    Kalamazoo, Michigan    December 7, 2015

Exactly 74 years ago today I was a 13 year old on the ground watching my older brother fly around an airport in northwestern Ionia County.

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