families as biotic units?

[Les Kaufman]

Allan, the biological significance of taxonomic families varies all over
the map.  In general, they are probably not units of selection.  However,
in tightly knit groups like some of the Dipterocarpaceae, the tenets of
species selection might apply.  In other words, if an environment is
dominated by a group of organisms with a common ancestor and shared
vulnerabilities, they might tend to respond to strong selective forces in
similar ways, thus behaving as if they comprised a unit of selection.

Les Kaufman
Boston University Marine Program
lesk at bio.bu.edu
617-353-5560 office
617-353-6965 lab
617-353-6340 fax


On Sun, 28 Feb 1999, Allan Shanfield wrote:

> Dear Taxacomers,
>
> Please forgive the simplistically broad scope of my question but I am
> interested in: Do families act as biological units? - especially in
> terms of competition both current and in the paleo record.
>
> To wit: Witness the broad success of Dipteerocarpace and its numerous
> guilds within as demonstrated by M. Ashton- perhaps at expense of other
> families. It has been attributed that there is a mycorrhizal component or
> who that arrives at a place first stays but still..
>
> And the success of some laurasian/arcto-tertiary families that ovveran
> tropical montane highlands, perhaps at expense of more Neotropical (and
> maybe mostly Gondwanan families).
>
> If anyone has any references in this regard I would greatly appreciate
> this (perhaps best directy email me for this may diverge too far from
> Taxacom's mission). If desired, I can cite my references either personaly
> or via personal email.
>
> Was/is there competition at the family level, has this been tested or
> no...from my vantage point there does seem to be evidence that some
> familes are more vigorous than others. If so, then have certain
> characteristics been evaluated (the question is "what" of course).
>
> Thank you very much.
>
> Sincererly,
>
> Allan Shanfield
>
>
> 1 Shields Ave.
> Dept. of Environmental Horticulture
> UC Davis, CA 95616
>