Posted on 05/20/2006 6:02:56 PM PDT by Al Simmons
Fetus' Feet Show Fish, Reptile Vestiges By Jennifer Viegas, Discovery News
May 18, 2006 — The feet of human embryos taking shape in the womb reveal links to prehistoric fish and reptiles, a new study finds.
Human feet may not look reptilian once babies emerge from the womb, but during development the appendages appear similar to prehistoric fish and reptiles. The finding supports the theory that mammalian feet evolved from ancient mammal-like reptiles that, in turn, evolved from fish.
It also suggests that evolution -- whether that of a species over time or the developmental course of a single organism -- follows distinct patterns.
In this case, the evolution of mammalian feet from fish fins to four-legged reptiles to four-limbed mammals to human feet appears to roughly mirror what happens to a maturing human embryo.
"Undoubtedly there are clear parallels between the mammal-like reptilian foot and the human foot," said Albert Isidro, an anthropologist at the Autonomous University of Barcelona, Spain and lead author of the study, which appeared in the journal The Foot.
Isidro and colleague Teresa Vazquez made the determination after analyzing fossils of a number of mammal-like reptiles that lived from 75 to 360 million years ago. The scientists also studied fossils of osteolepiform fish, which appear to be half fish and half reptilian. These fish lived 400 million years ago and had lungs, nostrils and four fins located where limbs would later be found in four-footed reptiles and mammals.
In 33-day-old human embryos, the scientists observed "the outline of a lower extremity in the form of a fin, similar to that seen in osteolepiform fishes." As the embryo continued to develop, the researchers focused their attention on two foot bones: the calcaneous, or heel bone, and the talus, which sits between the heel and the lower leg.
At 54 days of gestation, these two bones sit next to each other as they did within the reptile herbivore Bauria cynops, which lived around 260 million years ago. This ancient reptile had flat, crushing teeth and mammalian features.
At eight and a half weeks of gestation, the researchers found the two embryonic foot bones resemble those seen in the Diademodon vegetarian dinosaur, which lived around 230 million years ago.
"We can tell that the embryo is half way between the reptiles and the mammals (at this stage)," Isidro told Discovery News.
The two foot bones continue to develop until, at nine weeks, they resemble that of placental mammals as they emerged 80 million years ago.
This development of feet in the human embryo mirrors how the foot evolved over millions of years beginning with fish and ending with early mammals, according to the scientists.
Supporting the fish/foot link was the discovery last month of a new species, Tiktaalik roseae, which lived 375 million years ago. It had fish fins and scales, but also limb parts found in four-legged animals.
"Tiktaalik blurs the boundary between fish and land-living animals both in terms of its anatomy and its way of life," said Neil Shubin, professor and chairman of organismal biology at the University of Chicago and co-author of a related paper in the journal Nature.
H. Richard Lane, director of sedimentary geology and paleobiology at the National Science Foundation, said, "These exciting discoveries are providing fossil ‘Rosetta Stones’ for a deeper understanding of this evolutionary milestone: fish to land-roaming tetrapods (four limbed animals)."
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Actually, it kind of shows that they all have the same common ancestor.
YEC INTREP - shades of Haeckel
On what basis do you declare the similarities superficial?
Makes you fairly question an evolutionist's inherent powers of observation -- or lack thereof -- when one is blinded so by their own foolish pre-suppositions and an anti-science agenda.
Rehashing the same old failed play book. Kinda reminds you of the Democrats, doesn't it?
Evo's speak with about the same amount of credibility -- not to mention the same smarmy bile -- as Ward Churchill does, and have more in common with Democrats, than they'll ever admit here on FR.
Since the Creationists are the only honest scientists in these debates, we can just remain content to remind Evo-dem Dweepers of that and watch them all just slink off for the darker places from whence they came.
You left off the satire tag.
(I know its satire because nobody in their right mind would believe what you wrote.)
<< You left off the satire tag. >>
Well -- if it ain't satire, then it is a strong candidate for the "This is your brain on creationism" list. It's got almost everything it needs, except for the Nazis and the connection to Islamic terrorists.
Sometimes I think they sit around trying to think up things to say to make that list, on purpose. It's a badge of honor.
LOL What a hoot. Some evolutionists will strain at anything in order to bolster their flagging faith in their chosen 'religion'.
I would comment to you the works of St Augustine, as well as Pope John Paul The Great's statement on the evolution issue...
This the one you mean?
Usually, even a non-Christian knows something about the heavens, and the other elements of the world, about the motion and orbit of the stars and even their size and relative positions, about the predictable eclipses of the sun and the moon, the cycles of the years and the seasons, about the kinds of animals, shrubs, stones, and so forth, and this knowledge he holds to be certain from reason and experience. Now it is a disgraceful and dangerous thing for an infidel to hear a Christian, presumably giving the meaning of Holy Scripture, talking nonsense on these topics; and we should take all means to prevent such an embarrassing situation, in which people show up vast ignorance in a Christian and laugh it to scorn. The shame is not so much that an ignorant individual is derided, but that people outside the household of faith think our sacred writers held such opinions and, to the great loss of those for whose salvation we toil, the writers of our Scripture are criticized and rejected as unlearned men. If they find a Christian mistaken in a field which they themselves know well and they hear him maintaining his foolish opinions about our books, how are they going to believe those books in matters concerning the resurrection of the dead, the hope of eternal life, and the kingdom of heaven, when they think their pages are full of falsehoods on facts which they themselves have learnt from experience and the light of reason? Reckless and incompetent expounders of Holy Scripture bring untold trouble and sorrow on their wiser brethren when they are caught in one of their mischievous false opinions and are taken to task by those who are not bound by the authority of our sacred books. For then, to defend their utterly foolish and obviously untrue statements, they will try to call upon Holy Scripture for proof and even recite from memory many passages which they think support their position, although they understand neither what they say nor the things about which they make confident assertions [quoting 1Ti. 1:7].St. Augustine, The Literal Meaning of Genesis, 1:42-43.
Well, if either one of them said that the appearance of the unborn child's appendages at a particular stage of growth prove evolution, they'd be just as looney as these evolutionists. (Neither one ever said such a silly thing.)
Was Augustine a literalist? Did he believe that a 'day' (evening and morning) in Genesis 1 was a literal day?
<< Well, if either one of them said that the appearance of the unborn child's appendages at a particular stage of growth prove evolution, they'd be just as looney as these evolutionists. (Neither one ever said such a silly thing.) >>
And neither did the article. But don't let that stop you from inserting the rest of your leg into your mouth. Science doesn't "prove" theories -- it either succeeds or fails in "disproving" them.
Augustine was a pretty smart guy.
LOL
Not at all. Please read posts 96 thru 102 above, and then read post 123 and follow the link therein.
So, having gotten up to speed, what's your take on the marsupial eggshells and egg teeth? On the migrating mammalian earbones?
Remember Haeckel hypothesized that embryos resemble the adult stages of their ancestors, so that in some sense we actually are fish, amphibians, reptiles during gestation. This has not been taken seriously since about 1900.
However, the facts that led him to this hypothesis won't go away.
... blinded so by their own foolish pre-suppositions and an anti-science agenda. ... Kinda reminds you of the Democrats, doesn't it? ... Evo's speak with about the same amount of credibility -- not to mention the same smarmy bile -- as Ward Churchill ... more in common with Democrats, than they'll ever admit ... Since the Creationists are the only honest scientists in these debates [wow] ... Evo-dem Dweepers ... slink off for the darker places from whence they came.
Res ipsa loquitur.
Here's a pop quiz: give a reason why the giraffe was designed to have an extra fifteen feet of laryngeal nerve.
That's a theological question then isn't it?
Seems to be what this article is saying:
The feet of human embryos taking shape in the womb reveal links to prehistoric fish and reptiles, a new study finds. Human feet may not look reptilian once babies emerge from the womb, but during development the appendages appear similar to prehistoric fish and reptiles.
That's a theological question then isn't it?
There is a simple and elegant explanation for the nerve in standard biology.
The question is, is there an explanation within creationism or ID. If the hypothetical designer is a god, then it's a theological question. If the hypothetical designer is a space alien, then it's an engineering question.
Compare his hypothesis with von Baer's laws.
This latest research is showing that some parts of the embryo resemble some parts of a reptile (or fish, etc)
As I've said above, there are some really interesting phenomena here, such as the marsupian egg shells and teeth.
The fact that Haeckel's theory is false doesn't make these facts go away, and any theory of biological development has to explain them. The ToE does so, creationism and ID, as usual, have nothing of substance to add.
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