Pray, what is a species?
This is a very serious question.
Michael Roberts
----- Original Message -----
From: "Jonathan Clarke" <jdac@alphalink.com.au>
Cc: "'ASA List'" <asa@calvin.edu>
Sent: Wednesday, January 31, 2001 7:12 AM
Subject: Re: Examples of new species
> Hi Al
>
> I have specific references for some of them.
>
> Stanley's 1979 book "Macroevolution" on pages 40-47 mentions a number of
examples of recent speciation, including the Hawaiian moths (not fruit
flies, my memory was false) and copepods (not fish) in reservoirs. The
Hawaiian
> moths belong to the endemic genus Hedylepta. Five species (plus others
not described at the time) form a clade of banana-eating moths. Bananas
were introduced by humans about 1,000 years ago. The non bananaiverous
members
> of the genus feed on palms, although will also feed on bananas. These
species must have evolved since humans introduced the plant. The planktonic
copepod Cyclops dimorphus appeared in the Salton Sea about 30 years after it
> formed. Its closest relatives would be riparian species.
>
> The sub-antarctic rodents were mentioned to me by R. J. Berry (editor of
Science and Christian Belief) who did a lot of the basic work on them. Some
have different chromosome numbers to the parental mice. A similar example
> is provided in Stanley by the Faeroe island mouse (Mus musculus
faeroensis) which has, depending on the author, been placed in a separate
sub species or species. It was introduced 250 years ago.
>
> The Australian fruit flies I heard about on an ABC radio program. a friend
who worked for the Queensland museum told me about the adaptation of local
arthropods to Pinus radiata.
>
> A great many observed examples of speciation in the wild and laboratory
can be found at <http://www.talkorigins.org/faqs/faq-speciation.html> and
<http://www.talkorigins.org/faqs/speciation.html>. Examples there include:
>
> The evening primrose (Oenothera lamarckiana), which has a chromosome
number of 2N = 14. Variants have been observed which have a chromosome
number of 2N = 28. These are unable to breed with O. lamarckiana and have
been named
> O. gigas.
>
> The Kew Primrose (Primula kewensis) was produced by artificially crossing
Primula verticillata and P. floribunda to produce a sterile hybrid.
Polyploidization occurred in a few of these plants and produced fertile
offspring.
> The process has been observed to occur spontaneously on a number of
occasions.
>
> The genus Brassica contains several important (though not always popular)
food plants, including kale, cauliflower, broccoli. The different species of
Brassica appear to be the result of artificially selected hybrids, B.
> carinata (n = 17) may be recreated by hybridizing B. nigra (black mustard,
n = 8) and B. oleracea (cabbage), B. juncea (n = 18) may be recreated by
hybridizing B. nigra and B. campestris (turnip, n = 10), and B. napus (n =
> 19) may be recreated by hybridizing B. oleracea (cabbage) and B.
campestris.
>
> Hope this helps
>
> Jonathan
>
> Mccarrick Alan D CRPH wrote:
>
> > Jonathan Clark wrote:
> >
> > >JC. This is understating the evidence, which goes far beyond toxin
resistance or even industrial melanism.
> > >Speciation has been observed in historic times when new ecological
niches have been created. Example I
> > >recall include as introduced rodents in sub-Antarctic islands,
appearance of indigenous arthropods to feed on >introduced plants in
Australia, similar appearance of fruit flies to feed on bananas in Hawaii,
and speciation
> > >events of fish adapted to flowing waters to tranquil waters. The
changes involved in these examples included
> > >in feeding strategies, limb and jaw morphology, and chromosome number.
> >
> > Jonathan:
> >
> > Could you give some references for these items.
> >
> > Al McCarrick
>
>
>
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