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Original Message by Jaime A. Headden
Saturday, 28 December 2002 18:19
> <"Sympatric" refers to neither nor. Instead it's from Greek syn, together,
> and Latin patria, fatherland -- species that live in the same area are
> Though this may be a more lay definition, the operating definition I had
> was this one:
> "Definition: speciation without spatial separation of a population or
> speciation from within a population."
Ah. This is the definition of "sympatric speciation", not of "sympatric". :o)
> This latter definition has nothing to do with geography,
Sure: "spatial separation"; if a geographical barrier arises "within a
population" then there are 2 populations. :-)
> but refers
> indeed to relationship, or rather that "parent" stock from which two
> lineages might derive. Sympatry is literally "same parentage."
To derive sympatry directly from pater (father) rather than from patria would
produce a conflict with allopatry.
> <*Icaronycteris* has a rather long tail, but very few vertebrae in it.>
> This is the case for many long-tailed rodents, and one reason why murids
> do not have very prehensile tails.
It's more extreme in *I.*. Under 20 vertebrae.
> <-- Primatomorpha, both morphologically and molecularly, includes
> Dermoptera and Primates (and Plesiadapiformes).>
> My structure was that Primates ends before lemuriforms join.
> Primatomorpha being Primates plus Lemuriformes. If you have a definition
> that is based on other sources, tell me.
I have never seen Lemuriformes, or lemurs not being primates. AFAIK even the
relatively new term Euprimates includes lemurs (but not Plesiadapiformes).
> <Molecules don't find Archonta, instead
> |--Eulipotyphla (shrews, moles, hedgehogs)
> This is one molecular tree.
In fact, 2 or 3. I haven't seen the trichotomy as such, but either Euungulata
(Cetartio- + Perissodactyla) or Zooamata (Perissodactyla + Ferae). Apart from
Waddell et al., both papers by Murphy et al. (2001, Nature) find the same.
Madsen et al. (2001, Nature) finds bats in more derived positions within
Laurasiatheria, but with fewer nucleotides and fewer taxa.
> There is a symposium volume out there in
> _Systematic Biology_ (I think) [...] If you will persue the archives, you
> will find some extensive discussion on this matter around late 2000 or so.
http://www.cmnh.org/dinoarch/1999May/msg00287.html mentions a symposium
volume in Systematic Biology. The only changes that have happened since is
that Atlantogenata is now commonly regarded as paraphyletic, and that I've
never seen hedgehogs being basalmost placentals, must have been a long-branch
attraction type of thing. This same e-mail also mentions the classical
morphological McKenna & Bell tree (1997), which has Archonta, as disagreeing
strongly with the molecular evidence.
Well, I'll go and look up the actual volume, which the biology library
but not before January 3rd.
> <The name Scrotifera suggests that there are one or two potential
> morphological synapomorphies... so we can probably wait for a paper with a
> reconciliation, as is _slowly_ happening with Afrotheria.>
> So far, all morphological support I have seen for Afrotheria is based on
> plesiomorphies for placentals in general. Is there more consensus from
> your perspective on actual autapomorphies?
There's not much support. More fossils from the Paleogene of Africa are
sorely needed. There's testicondy (if I remembered the term correctly) in
elephants and tenrecs, don't ask me where else; there's some dental
similarity between the oldest members of Macroscelidea and Proboscidea but
not Glires, and some cranial dissimilarity between basal Hyracoidea and
Perissodactyla. Scroll to the end of
http://www.cmnh.org/dinoarch/2002Oct/msg00124.html and then up to the quote
"Paleontologists doubted Afrotheria too!" -- I cited "thise" from an
abstract. My typo, not theirs, for "those".
- Re: bats
- From: "Jaime A. Headden" <firstname.lastname@example.org>