Comments to Cladistics/Eclecticism, part 3
releech at TELUSPLANET.NET
Fri Feb 8 22:26:25 CST 2002
I agree with Susanne and I disagree with you. There can be physiological
differences that create real species - i.e., sexual species that are
morphologically indistinguishable (with today's methods!) that do not breed
with one another. We call them cryptospecies, and a few other names.
Perhaps one of the best examples is the crickets which breed and chirp at
different times of the year, and when last I read, they were morphologically
indistinguishable. A barrier does not have to be an eye-ball (or
microscope) observable physical difference. Not all physiological
differences are expressed by an observable physical difference.
----- Original Message -----
From: "Gurcharan Singh" <singhg at SATYAM.NET.IN>
To: <TAXACOM at USOBI.ORG>
Sent: Friday, February 08, 2002 9:53 PM
Subject: Re: Comments to Cladistics/Eclecticism, part 3
> Susanne Schulmeister writes:
> >6. Speciation backwards?
> >We had this example with some humans flying to Mars.
> >If these guys come back after some time and they are
> >still able to interbreed with the humans on Earth, it
> >is obviously still the same species. If they have been
> >completely isolated from us, with no exchange of
> >genetic material, long enough, there might develop a
> >reproductive barrier. If the humans from Mars then
> >come back and they cannot have fertile offspring with
> >the humans on Earth, the Martians and Earthlings must
> >be considered different species.
> Well yes they should have also developed some morphological differences
> along to go with reproductive barriers otherwise it will be futile. The
> purpose of systematics is defeated if the species recognised are not
> identifiable (for which we need some morphological features), should
> maintain these features through generations (should produce similar
> offsprings true and not interbreed with other species in nature). We have
> first to identify Martians and Earthlings before you can call them
> >You circumscribed this as: "Species A budds off
> >species B."
> >This thinking is based on a morphological species
> >concept, which sees species as morphologically
> >distinguishable entities. As I said above, this
> >concept is incompatible with Cladistics and, by the
> >way, is completely outdated.
> I think we are going back to the same bebate when Experimental
> during the middle of last century thought they are much superior to
> taxonomists. The problems arise when one category of workers start feeling
> themselves superior. To me there is no conflict between Morphological
> species concept and others particularly those based on reproductive
> barriers. To me almost all (with a minuscule number of exceptions) species
> recognised on morphological basis by Linnaeus, his predesors and followers
> and which exhibit sexual reproduction are still recognisable distinct
> species because they have also developed reproductive barriers with other
> It is time we started respecting those practicing other approaches of
> identify areas of understanding and find solutions to critical problems,
> I am sure they are few (like vicariants, sibling species, microspecies).
> Gurcharan Singh
> Dr. Gurcharan Singh
> Department of Botany
> 932 Anand Kunj
> Sri Guru Tegh Bahadur Khalsa College Vikas Puri
> University of Delhi , Delhi-110 007, INDIA New
> Email: singhg at satyam.net.in; singhkg at id.eth.net
> Phone: 5531534 Cell: 9810359089
More information about the Taxacom