Hi Birdo's
This is the openning of a can of worms my friends. One problem is that there
are confilicting opinions on what constitutes a species: Is it a population
which recognises others within the group as breeding partners (what about
hybridisation? What about Clines and Races? Where does that blurry line cut
off one group from another?), Is it shared morphology? Evolutionary
concepts, or one of several other factors over which the arguments rage.
Crikeys, if it's a breeding population, where does that lead many of the
species of life which which breed asexually, etc., for a start?
Other concepts pay no homage to the realities which birds as species within
their various ecologies actually move. All species are constantly changing
with gene flow and selective forces constantly working with and against each
other, sometimes throwing up new species, but always refining. To fall into
the malaise of constancy in a continually chaning environment may well lead
to extinction. Each bird cares not one jot for our philosophical or
scientific maunderings, it just eats, sleeps, defends its turf and does
whatever is required to attract a mate. The mates will recognise each other
(how this is done could be the subject of a very long email) and so life
goes on. What owl ever cared about an intricate Cladogram (speciation
chart), for instance? He or she is just getting on with it.
Until species concepts are resolved, problems with classification are going
to continue and that means our Field Guides are going to vary a little or
maybe a lot (a growing number of Systematists wish to invoke a
classification system which will see a doubling in species, and this
system - based on the Phylogenetic Species Concept - has a great deal of
merit indeed). My guess is that, for birds - and possibly fishes, where this
debate is also raging - we are going to eventually realise that we need to
apply more than one system somehow or other: one system which recognises the
organism's viewpoint in terms of our need to understand avian ecology (the
Biological Species Concept, for example) and another which works on
evolutionary/phylogenetic concepts in terms of understanding the bigger
picture of Birds as a Class. I just don't think that one model is going to
fulfil all of our purposes at all times and especially that of the birds as
contributors to and beneficiaries of ecologies in which they reside. This is
not an area where we can make too many mistakes, as outcomes of studies and
the future of species will rely on our understandings in this matter.
Sorry if this seems a little confusing, but putting even part of this matter
into a short email is a real problem in itself.
Regards - Ricki
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