Cheetahs are a nice exmaple because it looks like they evolved themselves into a corner. They basically got as fast as they can be by shedding everything, I can’t see where they might go if they “wanted” to go faster, which is their thing, or if stronger they’d certainly lose speed.
No, they don’t. They have pharyngeal pouches but these don’t develop into anything like gills in human embryos. Recapitulation theory is bunk. This isn’t to deny that the pouches’ prescence shows common descent, because it does, but don’t call them gill slits.
Here’s a page Human embryos don’t have gill slits on EvoWiki where people are arguing both for and against the term “gill slits”. The first response is particularly relevent:
I’m not going to argue semantics. You can call them what you like, but don’t say I’m wrong when I’m using a common term.
[QUOTE=seriously, I just answered that]
invagination /0ɪnˌvadʒɪˈneɪʃ(ə)n/ noun. M17.
[ORIGIN Modern Latin invaginatio(n-), formed as in-² + vagina: see -ation.]
Orig., the action of sheathing something; esp. intussusception. Now usu., the folding in of a surface or membrane to form a hollow cavity or pouch; the cavity so formed.
[/QUOTE]
You quote part, and ignore all the places where it says “**resembling **gill slits” and “gill-like slits”. By the time we get to your quote, I think there’s been sufficient qualification to indicate that the bare-bones phrase you bolded is not, in fact, the whole truth.
I’m familiar with that page and the talk.origins discussion as well. - the relevant logical fallacy you’re going for there being “argumentum ad populum.” Suffice to say you and they are wrong - they aren’t gill slits because they never connect to any gills. This is not just pedantry: calling them “gill slits” just puts ammunition in the hands of IDers who can easily point to the proven made-up recapitulation diagrams and accuse us of another scientific fraud a-la Piltdown, and does nothing to indicate that we now know recapitulation theory is wrong. Which it absolutely is.
:rolleyes: Presumably we are supposed to think that Wittgenstein is the smart one here (and no doubt Anscombe, as one of his most faithful acolytes, thought so too). However, he ain’t. This is really just a demonstration of Wittgenstein’s literalism, and his tin ear for (and ignorance of) the historical.
Mr. Dibble, I already told you I’m not interested in arguing semantics with you. You don’t like their usage of the term, that’s a problem you have with that community. And note that that is a community page, not just the general population. As long as they are using that term, I am allowed to as well.
Get your own house in order. Don’t come to me to complain about it.
It’s not semantics. The features are not correctly called gill slits, regardless if they are called that colloquially in some contexts. Neither Wikipedia or EvoWiki are authoritative sites. Mr. Dibble was quite correct to clarify your use of the term. Just because other people are misusing the term elsewhere doesn’t justify your misusing it here.
It’s an incorrect and ignorant usage that contributes to the misunderstanding of evolution, and so should best be avoided. Mr. Dibble’s clarification was entirely on target. I am not sure why you are continuing to defend the term.
Is recapitulation theory dead? I thought it had been scaled back, refined and reformed, brought up to date with advancing data, but that the basic principle is still sort of right. Fetal development goes through certain stages that resemble broad phases of evolutionary history.
In the past, the theory was taken much too far, and used to try to make predictions and discoveries. Okay, that part is wrong. But isn’t there some validity remaining?
It’s your own fault if you insist on using a term that is incorrect after it has been pointed out. In any case, Wikipedia and EvoWiki are not “my house.” My house is GQ on the Straight Dope, and I’m trying to put it in order.
Haekel’s Recapitulation Theory, in which organisms go through embryonic stages that represent adult stages of ancestors, and which is often characterized as “ontogeny recapitulates phylogeny,” is defunct and discredited. However, there are similarities between embryonic stages of related organisms. This has been stated as “ontogeny recapitulates ontogeny.”
