[Taxacom] The Reality (or not) of Species (again!)`

Richard Pyle deepreef at bishopmuseum.org
Sun Sep 14 06:17:06 CDT 2008


> Curse you Pyle!  (again!)  After months of blessed abstinence 
> from this abominable topic, I felt that sight was 
> returning...  but alas, it is obviously not to be... :)

If my message did nothing else other than prompt you to write your very
good, and very enjoyable post, then I will go to bed tonight knowing that it
was well worth it!

Good, and enjoyable though it was, you know damn well I can't stop myself
from commenting ... at least a *little* bit! :)

Namely:

- The Language analogy is excellent, and I've used it as well.  In the same
way that we define words, and those definitions of words change over time
and across communties; so too do we define species, which are subject to
similar dynamics of imprecision.

- Ultmately, nothing is a spectrum or a continuum (quantum physics, and
all).  It's all an issue of scale.  And the scale of individual generations
of organisms is several orders of magnitude finer than the scale of what
most of us think of as "species".  So, in the context of chopping up the
world into units of species; viewing the history of life on Earth at the
scale of individual reproductive events is effectively a continuum.

- The puff of smoke image is not intended as a "model" for the evolutionary
process; but rather a stylistic representation of the fact that, over the
scale of living history implied by a typical cladogram, the actual chain of
reproductive events of the organisms are as fine as the particles of smoke;
and thus from that scale *appear* as though they are a continuum. It serves
to remind us that the seemingly real, seemingly discrete clusters we
conveniently call "distinct species", came to be via a process that occurred
at much, much higher resolution than "speciation events".

> Is this characterization of alpha vs phylo perspectives of species an
> example of an incipient speciation event in itself?   Similarities and
> differences vs descent of the shared and derived?  Defined vs 
> discovered?  Fuzziness vs rectilinear?  The Little Endians of 
> Lilliput vs the Big Endians of Blefuscu?

Don't forget the leprechauns.

>  Whatever - it is still a damned egg...  :)   ...and it came *after*
> the chicken...

As my wife likes to point out to her high-school biology students:  Eggs
existed on this planet LONG before chickens did.

> "Species are "real" only in the sense that at any given 
> moment of time, the derivitives of evolution (i.e., 
> organisms) form a clumpy pattern, rather
> than smooth continuum."   We need to discuss this sentence too.  Not
> "only" the word "only", but about whether it is the organisms, the
> species or the character is the derivative of evolution.   

It depends on what your meaning of the word 'is' is.

g'night...

Rich






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