Posted on 05/07/2008 10:44:35 AM PDT by blam
Platypus genome is as weird as its looks
18:00 07 May 2008
NewScientist.com news service
Emma Young
It's part-reptile, part-mammal, part-bird – and totally unique. Two centuries after European scientists deemed a dead specimen so outlandish it had to be a fake, the bizarre genetic secrets of Australia's platypus has been laid bare.
Platypuses lay eggs and produce venom like some reptiles, but they sport furry coats and feed their young with milk like mammals. The odd creatures are classed as monotremes, with only one close relative – the echidna.
But as primitive mammals that share the same ancestor as humans, a study of the animal's genome can improve biologists' understanding of how mammals evolved, while illuminating the platypus's strange physiology.
Wesley Warren at Washington University in St Louis, Missouri, led the international team that sequenced the platypus genome. As expected, they found an amalgam of some ancestral reptile and some newer mammalian features. But there were also surprises.
Ancient milk
And while the gene that the human sex-determining gene evolved from is present in the platypus genome, it seems to have nothing to do with sex determination. So, that function must have evolved after the platypus split from our common ancestor, about 166 million years ago.
However, by that time, milk production was well-evolved. The platypus has the same repertoire of milk protein genes as a cow or a human. Clearly, milk evolved long before we evolved to give birth to live offspring, says team member Jenny Graves at the Australian National University in Canberra.
The team also investigated the genes for the platypus toxin, which males deliver via a barbed spur on their heel. While the toxin is similar to a snake's – adapted from natural neurotransmitters and other proteins –
(Excerpt) Read more at newscientist.com ...
Not so. The way to tell if 2 different looking animals are the same or different species is to cross-breed them and see if fertile offspring result.
ME: because it has to, dont you get it yet?
YOU:
How does that establish that the platypus and humans “evolved from the same ancestor” as the article claims?
So, you don’t like chemistry and you don’t like phenotypic similarities.
What do you like?
BTW, you’d be surprised at the underlying similarities among domestic dogs. And the chemistry works beautifully.
My particular post #20 doesn’t. That was a reply to an earlier commenter who stated that there were “absolutely no fossil evidence for platypus-like creatures” or something to that effect.
To answer your question, you’d have to look at the larger body of fossil records, and genetic data available.
ME: oh good, please list these uneqivocal ‘transitions’ we creationists agree on, in the fossil record...and the creationists of note, who ‘agree’.
(stifling laffing up my sleeve)
YOU:
There are HUNDREDS of “transitional forms” in the fossil record that meet the definition of the creationists. However, ALL species are transitional species. That’s why there gone and new ones have arissen.
Not one fossil of a platypus-like (but not a platypus) creature has ever been found.
That’s your statement before somebody proved to you that those exact fossils have been found.
Similarity does not prove evolution.
That is an entirely different point than your first. Can you at least acknowledge that you were utterly wrong on point one?
Aye, and if my mother had wheels, she’d be a wagon.
ME:
No, what you mean is we would have to look at the evolutionary INTERPRETATION of the fossils, that allows NO OTHER INTERPRETATION of the fossil record, other than saying ‘see, these are transistions’.
(that’s called a stacked deck)
YOU:
My particular post #20 doesn’t. That was a reply to an earlier commenter who stated that there were “absolutely no fossil evidence for platypus-like creatures” or something to that effect.
To answer your question, you’d have to look at the larger body of fossil records, and genetic data available.
Let's have it your way. Or rather the Chinese mythological way. Prove it wrong.
Sounds like one of those original movies for the SciFi Channel. "Platypus:Duckbill of Destruction!"
You misquote me. I said "meets the definition". I am fully aware that creationists will never accept anything as evidence that contradicts their Bible stories.
What is a transitional fossil?
The term "transitional fossil" is used at least two different ways on talk.origins, often leading to muddled and stalemated arguments. I call these two meanings the "general lineage" and the "species-to-species transition":
"General lineage":
This is a sequence of similar genera or families, linking an older group to a very different younger group. Each step in the sequence consists of some fossils that represent a certain genus or family, and the whole sequence often covers a span of tens of millions of years. A lineage like this shows obvious morphological intermediates for every major structural change, and the fossils occur roughly (but often not exactly) in the expected order. Usually there are still gaps between each of the groups -- few or none of the speciation events are preserved. Sometimes the individual specimens are not thought to be directly ancestral to the next-youngest fossils (i.e., they may be "cousins" or "uncles" rather than "parents"). However, they are assumed to be closely related to the actual ancestor, since they have intermediate morphology compared to the next-oldest and next-youngest "links". The major point of these general lineages is that animals with intermediate morphology existed at the appropriate times, and thus that the transitions from the proposed ancestors are fully plausible. General lineages are known for almost all modern groups of vertebrates, and make up the bulk of this FAQ.
"Species-to-species transition":
This is a set of numerous individual fossils that show a change between one species and another. It's a very fine-grained sequence documenting the actual speciation event, usually covering less than a million years. These species-to-species transitions are unmistakable when they are found. Throughout successive strata you see the population averages of teeth, feet, vertebrae, etc., changing from what is typical of the first species to what is typical of the next species. Sometimes, these sequences occur only in a limited geographic area (the place where the speciation actually occurred), with analyses from any other area showing an apparently "sudden" change. Other times, though, the transition can be seen over a very wide geological area. Many "species-to-species transitions" are known, mostly for marine invertebrates and recent mammals (both those groups tend to have good fossil records), though they are not as abundant as the general lineages (see below for why this is so). Part 2 lists numerous species-to-species transitions from the mammals.
Transitions to New Higher Taxa As you'll see throughout this FAQ, both types of transitions often result in a new "higher taxon" (a new genus, family, order, etc.) from a species belonging to a different, older taxon. There is nothing magical about this. The first members of the new group are not bizarre, chimeric animals; they are simply a new, slightly different species, barely different from the parent species. Eventually they give rise to a more different species, which in turn gives rise to a still more different species, and so on, until the descendents are radically different from the original parent stock. For example, the Order Perissodactyla (horses, etc.) and the Order Cetacea (whales) can both be traced back to early Eocene animals that looked only marginally different from each other, and didn't look at all like horses or whales. (They looked rather like small, dumb foxes with raccoon-like feet and simple teeth.) But over the following tens of millions of years, the descendents of those animals became more and more different, and now we call them two different orders.
There are now several known cases of species-to-species transitions that resulted in the first members of new higher taxa"
http://www.talkorigins.org/faqs/faq-transitional/part1a.html#tran
Yes, site talkorigins, the well known anti christian, pro atheism site...
“meets the definition”?????
you mean, MEETS THE EVOLUTIONISTS DEFINITION not a creationist definition.
You folks see what you want to see.
An easy rule when discussing this with folks like you is:
if it ‘prove’ evolutionism, then it proves it.
if it doesnt prove or provide evidence for evolutionism, then IT STILL PROVES IT.
anything we say and do PROVES EVOLUTIONISM, and all others ideas are ruled out as non science and those who disagree are too stupid and ‘dont understand how science works’.
I was flummoxed when I read this, as it is reported with a straight face and no commentary, although...
It illustrates perfectly the dilemma that the doofuses who attack the movie "Expelled" without having seen it must face, sooner or later:
In their universe, that original statement makes no sense; that a biological feature will evolve, to satisfy a need thousands, perhaps millions of years later.
Move right along folks, nothing to see here...
Rather than getting angry, just give me YOUR definition of a transitional fossil
The platypus is proof positive that God has a sense of humor.
Okay then. I take it that you're one of those who disagree. Don't buy evolution. I suppose you've bought into the Biblical "explanation".
Provide the logical arguments in the said "explanation" that won you over.
No, the platypus is a transitional form between reptiles and mammals. No transitional forms between mammals and birds ever existed, as both of those classes evolved ultimately and independently from reptiles.
The "duck bill" is something that has arisen independently in mammals, birds, and fish (e.g., the paddlefish), much as flight arose independently in multiple groups (e.g., birds, insects, mammals, etc).
The following transitions clearly describe the evolution of the horse: Hyracotherium --> Orohippus --> Mesohippus --> Miohippus --> Kalobatippus --> Parahippus --> Merychippus --> Hipparion --> Pliohippus --> Dinohippus --> Plesippus --> Equus.
The following fossils similarly identify the lineage for whales: Archaeocetes --> Pakicetus --> Ambulocetus --> Rhodocetus --> Basilosaurus.
You might want to reconsider your thoughts on this. The platypus lays eggs. The egg serves as an external uterus that provides for the fetus until birth. Milk is used for sustenance of the infant AFTER birth, so the method of birth is irrelevant to the value of milk to offspring,
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