Platypuses (Ornithorhynchus anatinus) are excellent examples of primitive mammals that retain some reptilian features – such as egg laying. But, for some reason creationists seem to claim the platypus is a problem foe evolution. I often get this link thrown at me as if it proves that platypuses are a mosaic that contain parts from reptiles, mammals and birds, and therefore could not have evolved.
Let’s look at some of the creationist claims and expose more lies and misrepresentation.
1. It has a bird’s bill.
No it doesn’t! A bird’s bill is mainly made of the protein keratin. A platypus’s is leathery, flexible and contains numerous sensory pits
2. It lays eggs like a bird.
It may lay eggs, but they have leathery shells like reptile eggs. They are not surrounded by a shell like those of birds. This is what you would expect with the evolution of mammals: egg laying “reptiles” becoming egg laying mammals, which become live birth giving mammals. So, where is the problem?
3. It has a spur on its hind limb that produces a toxin similar to that found in reptiles.
Again, so what? That is what you would expect if they evolved from reptiles. In the link above, the author is also misleading. The platypus toxin actually evolved independently of the reptile venom. Both evolved from beta-defensin genes, but different classes of them , so although they are similar, there is no claim that one is descended from the other – that is creationists being naughty trying to play up the mosaic idea. The plan is to say Ha! Look they are almost identical to reptiles, but wait, they have genes found in birds too. Therefore evolution is wrong.
4. They contain genes for the egg protein vitellogenin. As the article claims, these genes are also found in fish and birds.
Again, we have some more naughtiness by omission. As the article is read, there is no mention of amphibians and reptiles. So, if it is not present in these groups, that would be a problem. Being a scientist, I’m not scared to make a testable prediction. I predict these groups contain vitellogenin genes (why don’t creationists make testable predictions? Answers on a post card). So, lets search the best database for finding peer reviewed scientific research publications (try it yourself). Let’s search for vitellogenin and amphibians. Well, no surprise there, 398 articles containing those key words, and plenty of papers on African clawed frogs (Xenopus laevis). What about searching for vitellogenin and reptile? This time, we get 62 publications describing its occurrence in snakes, crocodilians, iguanas and turtles. So, the evolutionary scenario of fish to amphibians to reptiles; which split into birds and mammals (via egg laying mammals) stays intact.
5. They contain ZPAX genes that are found in birds, amphibians and fish.
Let’s look at some of the creationist claims and expose more lies and misrepresentation.
1. It has a bird’s bill.
No it doesn’t! A bird’s bill is mainly made of the protein keratin. A platypus’s is leathery, flexible and contains numerous sensory pits
2. It lays eggs like a bird.
It may lay eggs, but they have leathery shells like reptile eggs. They are not surrounded by a shell like those of birds. This is what you would expect with the evolution of mammals: egg laying “reptiles” becoming egg laying mammals, which become live birth giving mammals. So, where is the problem?
3. It has a spur on its hind limb that produces a toxin similar to that found in reptiles.
Again, so what? That is what you would expect if they evolved from reptiles. In the link above, the author is also misleading. The platypus toxin actually evolved independently of the reptile venom. Both evolved from beta-defensin genes, but different classes of them , so although they are similar, there is no claim that one is descended from the other – that is creationists being naughty trying to play up the mosaic idea. The plan is to say Ha! Look they are almost identical to reptiles, but wait, they have genes found in birds too. Therefore evolution is wrong.
4. They contain genes for the egg protein vitellogenin. As the article claims, these genes are also found in fish and birds.
Again, we have some more naughtiness by omission. As the article is read, there is no mention of amphibians and reptiles. So, if it is not present in these groups, that would be a problem. Being a scientist, I’m not scared to make a testable prediction. I predict these groups contain vitellogenin genes (why don’t creationists make testable predictions? Answers on a post card). So, lets search the best database for finding peer reviewed scientific research publications (try it yourself). Let’s search for vitellogenin and amphibians. Well, no surprise there, 398 articles containing those key words, and plenty of papers on African clawed frogs (Xenopus laevis). What about searching for vitellogenin and reptile? This time, we get 62 publications describing its occurrence in snakes, crocodilians, iguanas and turtles. So, the evolutionary scenario of fish to amphibians to reptiles; which split into birds and mammals (via egg laying mammals) stays intact.
5. They contain ZPAX genes that are found in birds, amphibians and fish.
Note, there is no mention of reptiles here. That’s because they have not been looked for in reptiles – you won’t find it in pubmed. Here is another prediction for creationists, reptiles possess these genes – wait and see. The organisms that it has been studied in show a definite evolutionary relationship between groups, based on gene similarity see here.
6. Some of the sex chromosomes are like those of birds.
Platypuses have an unusual arrangement of sex chromosomes - there are 10 of them. They do follow the basic mammalian X Y sex determination pattern, with all X causing females and Xs and Ys together causing males. If they have evolved from reptiles, we would expect some similarities to reptilian sex chromosomes. Reptiles form 2 main groups when it comes to sex determination. Those were environmental factors determine sex and those where sex is determined by sex chromosomes (Z and W for female and two Zs for male). This is the system that birds have inherited. In the platypus, the Y chromosome seems to have evolved independently, with the X chromosome alone showing some similarity to both the reptilian and avian Z chromosome – from which it evolved.
7. They contain some avian like micro RNAs.
Guess what; at least one of the X chromosomes encodes some micro RNAs (see above).
Creationism has no evidence of its own and relies on dishonest misrepresentations and straw men concerning evolution.
I’m off to put some brights cards under the wipers of cars that have “you make Jesus cry” (puke-arama) stickers on them – again!
9 comments:
That was really interesting... I like the little platypus, they are great – look stupid, but great – they swim pretty quickly as well... I probably have around 30 odd pictures that do NOT contain a platypus I took at a zoo once... I got a foot in one, and a bit of a head in another I think. Rubbish really.
Anyway - goes to show, the creationist will try and mislead - if you don't know your stuff it could sound convincing... it would have buggered me - apart from I would be wise enough to ask someone who knows more (like yourself) who could not only point me to further research - but point out the errors in the argument.
(Though am I just trusting you because of your position of authority? – Nope, I am trusting science to keep you in check.)
Lee
They are cool aren't they.
Nope, I am trusting science to keep you in check.
Indeed, it is self critical and self correcting.
Also, if someone refutes evolution with good scientific evidence, they will get a well deserved nobel prize in my book - cant see it happening though - too much to explain away.
Billy: Also, if someone refutes evolution with good scientific evidence, they will get a well deserved nobel prize in my book - cant see it happening though - too much to explain away.
Yup. Fame, fortune and possible vindication of their faith await those who refute evolution.
Given the supposed shaky status of the theory of evolution, I wonder why it hasn't happened yet? ;-)
ps. Thanks for the lesson Billy. Kind of wish I'd done some biology back in the dark ages when I was in school :-)
Kind of wish I'd done some biology back in the dark ages when I was in school :-)
I kind of wish creationists had too
Billy: I kind of wish creationists had too
But that would ruin all the fun, wouldn't it :-)
"Creationism has no evidence of its own and relies on dishonest misrepresentations and straw men concerning evolution."
That was a bold statement. You proved no such thing in your little rant. I have never heard this argument about the platypus, but I still believe in creationism. Therefore, your claim that you disproved creationism is arrogant and ignorant. It's similar to me saying
"Nobody has ever seen a monkey turn into a human, therefore evolution has no basis in fact."
Bob Bowser: You proved no such thing in your little rant.
He did show that, when it comes to the typical creationist arguments against evolution using the platyus, that "Creationism has no evidence of its own and relies on dishonest misrepresentations and straw men concerning evolution."
Besides, it's not up to Billy to "disprove" creationism.
You're a creationist, you're making the positive assertion, it's up to you to show creationism fits the data, and is better (more parsimonious) than the current scientific theory of evolution.
A Nobel prize awaits you for doing so, though excuse me if I don't hold my breath :-)
Rian,
It does not surprise me that a creationist would jump to a conclusion other than the one I intended. I suppose it comes with quote mining all the time. How you jump from a dishonest tactic to claiming that I think I have suddenly disproved every creationist argument there is is a truely creationist quality.
I don't hold much hope that he will return with something meaty
Bob,
I think I have quite clearly shown in this case creationists lie. You may want to see the Ambulocetus post for a further lie regarding the pelvic girdle.
So, where is your evidence?
If you do have any evidence for creationism, we would genuinely like to hear it.
You proved no such thing in your little rant.
Apparently, producing facts to destroy a creationist "argument" is ranting. let's take the first claim - it is a fact that it's bill is structurally unlike that of a birds'. Do you call it a rant because you just dont like creationists being refuted?
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