Re: emu history

[Ronald Orenstein <ornstn@rogers.com>]

At 11:57 PM 1/13/2004, Nancy Cavanaugh wrote:

> Hmmm... that's interesting. Nothing I've read to date (and I've only been
> researching this for a couple of months, and 98% of that research has been 
> done
> online as books about emus, at least in the public sector, in the US are rare
> to non-existent) said anything about the emu being from a common ancestor 
> with
> the cassowaries. Who was the common ancestor? How did they evolve differently?

If you are planning to write a book bout emus - forgive me for saying this 
- you will have to do some research in a library at some point.  I have yet 
to see a book on ornithology that discusses emus that does not point out 
that cassowaries are their closest relatives, so I am a bit alarmed that 
you have missed this!

I realize you may be writing about emu farming rather than their biology, 
but you should still - at the very least - consult such basic books as the 
Handbook of the Birds of the World (Vol 1), The Handbook of Australian, New 
Zealand and Antarctic Birds (Volume 1), and Ratites and Tinamous by Stephen 
Davies, which summarize our knowledge of the birds and provide extensive 
references.


> I had read in several places that it is believed that the emu has evolved 
> very
> little from its earliest form. One would assume, based on that information 
> and
> what you've said, that the cassowaries probably evolved very little from 
> their
> earliest form. Has that been the case?

I really think you should check out some more authoritative sources!  I 
suspect that this is a misreading of the fact that emus (like other ratite 
birds such as ostriches) have a palate structure, called palaeognathous, 
that was once considered to be more "primitive" than the neognathous palate 
of other living birds (I think today there is no certainty that this type 
of palate evolved first or that the neognathous palate evolved from 
it).  Of course as we have no idea what the "earliest form" of the emu 
looked like (and what do you mean by "earliest form" anyway?), we cannot 
say how much it has changed since (of course if by earliest form you mean, 
say, a bacterium or a collection of DNA molecules in a membrane, you could 
argue that it has changed quite a lot!).

> Sorry for the typo on Mr. Cracraft's name. The erroneous spelling is from 
> a few
> websites where I found the information about when the dating of the emu
> happened. When did Mr. Cracraft announce his findings for the dating of the
> emu? Was it '71 or '73?

I think the paper you want to read is:

Cracraft, J. (1974).  Phylogeny and evolution of ratite birds.  Ibis 116: 
494-521.

Otherwise, why not get in touch with Joel and ask him?  He is 
Curator-in-Charge of Ornithology at the American Museum of Natural History 
in New York; see http://research.amnh.org/ornithology/personnel/jlc.htm for 
contact information, etc.


> You forgot about the extinct Tasmanian Emu which is supposed to be a sub-
> species of the "mainland" emu. =) Did they ever live on the mainlanda? How 
> did
> they get to Tasmania?

Presumbly they walked there when the two were connected, as did mammals 
like the Thylacine (though I suppose some sort of transfer over water is 
just possible even though emus are not prone to take a dip in the sea!).  I 
did not forget the Tasmanian Emu, but it is a subspecies, not a full 
species.

--
Ronald I. Orenstein                           Phone: (905) 820-7886
International Wildlife Coalition              Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2          mailto:ornstn@rogers.com