Families can be..

[Kipling Will]

Greetings  to all,


I don't think it is a good idea to confuse the category "Family", which is a level in a hierarchy and so a construct of the human mind that has no reality beyond this, and the "group" (=clade) that is defined by characters such that an individual organism either is or is not a member. A clade has (or we hope it has) some reality (history and future) or extension beyond our ability to perceive it. Only sister clades can
be compared in any strict sense as they are equal by definition. I don't think this precludes us from discussing various categories in terms of generalities. But caution is required.

In beetles, counting or comparing families or subfamilial groups is often problematic. For instance the groups designated as tribes by many (?most) current workers in Carabidae (ground beetles) are generally equal to the subfamilies of B.P. Moore (1965) and families of Jeannel (1942). If we make comparisons of the families of Adephaga (suborder including Carabidae) what should we use? Think how the choice of category
might alter our interpretations. A real example may be the recent publication on the relationship of diversity in phytophagus beetle and host plants (I don't have the reference here, perhaps someone can offer it to the group). How did the choice of the generic level effect this study?

have a great  day
kip




Francis Dov Por wrote:

> I basically agree that in many cases families are real biological units if they are well characterized by common morphology,physiology and behaviour and of course are monophyletic. Think for example of the Argulidae (carp lice) , ectoparasites of freshwater fishes, or Spongillidae, freshwater sponges, or Rhizophoracea, red mangrove or even Ocypodidae, littoral sand-living crabs. "Real" families tend to be worldwide.
> Indeed the "reality" of higher taxa becomes even more evident at the order and class level. In this sense , families or same level units (sub-super-, tribes) are the most problematic taxa.
> Dov Por

--

In short, variety is a great and most beautiful law of Nature; it is that which distinguishes her productions from those of art, and it is that which man often exerts his highest efforts in vain to imitate.

H.E. Strickland

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Kipling Will
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Dept. of Entomology
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