reply to post by ReturnofTheSonOfNothing
Fruit Bats (aka Flying Foxes, genus Pteropus) are not marsupials.
Oops. I plead guilty, yer 'onor. That was indeed a serious mistake.
However, your defense of winofiend's post, while good intentioned I'm sure, is just hiding his mistakes which were more than just 'technically
I am addressing this to you, ReturnofTheSonOfNothing (RoTSON) because you tried to explain what winofiend's point was. I appologize to you winofiend
if it sounds like I am talking to about you behind your back, I don't mean it that way, I just couldn't figure out what point you were trying to
make, and what I considered your badly misunderstood description of the thylacine almost made me think you were trying to deny evolution somehow. I
just couldn't work it out; sorry.
The thylacine for example, a marsupial, with all the characteristics of a canine. Evolved entirely separate from all other animal life, in a
completely different environment.
Yet had markedly similar characteristics to mammalian evolution.
The thylacine did not evolve separate from all other animal life, in any way shape or form. It was (is?) a carnivore. How could it evolve as a
carnivore if there was no animal life around? It it meant that it evolved 'differently' from all other animal life, winofiend was even more wrong.
There are lots of animals, all over the world that fill a similar ecological niche. Winofiend mentioned dogs, for example, and I mentioned the
Furthermore, winofiend correctly identifies the thylacine as a marsupial. Marsupials are mammals, of course they have "markedly similar
characteristics to mammalian evolution". What point is made by telling us that water is wet?
Not only but also, a thylacine may have looked superficially like some dogs look, but they did not behave like dogs. For a start, they were not hunt
in packs (though we don't know enough about them to say that as an absolute; there are apparently reports they might have hunted in small groups but
that may have been parents teaching their young). There are other animals superficially similar to dogs that are not dogs, for example the hyena.
Finally on that thought, marsupials evolved on Gondawanaland, as you say, and when the split occured, marsupials who happened to be 'caught' on
Australia/New Guinea continued to evolve as did those in America. They did not arise separately on Australia and America, they were just
geographically isolated some time later. In modern times, the thylacine was a 'relict', the isolated remnate of a larger population that died out on
the mainland (Tasmania was joined to the Australian mainland until the sea rise after the last glacial period about 10,000 years ago).
The fact that there are marsupials in America and Australia are not examples of 'convergent evolution'. The fact that there are thylacines, dogs,
and hyenas in different parts of the world are examples of "convergent evolution".
winofiend goes on to say:
Does this give any credibility to evolution working as it should,
In what way does that 'question' make sense? Evolution works the way evolution works. There isn't any right way for it to work; nor is there any
wrong way for it to work. There is just the way it does work.
winofiend tries to clarify what is meant by that question:
where the environment helps to shape the outcome of the life it contains?
This at least is an interesting question, albeit in my opinion more philosophical than scientific. Leaving aside that there is no 'working as it
should', does the environment 'actively' participate in evolution or does it 'passively' provide opportunities for exploitation. I vote for
passive, but perhaps others have different views.
Where it is not required, life will remain unchanged. Where it is an effervescent and volatile environment, life will be varied and different. There
is no requirement for things to change where there is no need to change.
This is a fundamental misunderstanding of evolution, I think. Life always changes. Even though some animals appear to continue in the same form for
many millions of years, they are never the less changing with every generation. For example, crocodiles were long considered to be 'living fossils',
but it has been shown that they are indeed actively evolving.
Why would life need to duplicate a spine? The structure exists as it does without need to improve in life that has evolved with it, and in other life,
it is completely missing, and replaced by an exoskeleton.
I just don't know where this comment came from. I can't find any reference to anybody asking about the spine in the thread. To whom is winofiend
conversing here, and what is the point being made?
There are several 'organs' that have evolved that do the same sort of thing in different animals. The eye has evolved at least 3 times (squid,
mammal, jellyfish); wings 2 (birds, bats).
I don't know about convergent evolution of spines, I haven't thought about it, but the divergence of vertebrates and invertebrates was very early
on. I don't know of any evidence that the spine evolved more than once, but I don't know of any absolute assertion that it didn't either. How would
we know? A fossil of a fish on one side of the world may or may not be the exact first individual that ever had a spine, but how would be know that or
distinguish it from the fossil of a fish on the opposite side of the world? How would we know that the spine was evolved separately or one was a
relative of the other?
I appologise again winofiend for talking away from you, I don't mean to offend, it's just the way my thoughts came together that I was addressing