Slashdot Mirror
Fish with Limbs
kpogoda writes "American scientists have unearthed the world's oldest arm bone, a 365-million-year-old fossil that provides key evidence that fish used limbs in water well before animals used them to climb up on land."
← Back to Stories (view on slashdot.org)
After all, it says in the article that the upper arm bone they found was "humerus"!
One of the typical arguments by creationists is how can evolution make these jumps from legs to fully functional wings. The latest thinking is that there's wasn't a giant leap, but rather a series of gradual steps between limbs that didn't impart flying, but still had some use.
For example, chickens don't fly very well, but have you ever tried to catch a chicken? Those "vestigial" wings sure impart bursts of speed and the ability to leap over obstacles.
It's neat to see the discovery of similar intermediaries between swimming and walking limbs. Evolution is an amazing and beautiful thing.
I love the standard creationist line that eyes couldn't have evolved - they must have been planned.
I once read an excellent rebuttal of that which described how to get from a photosensitive cell to a full eye while each stage had a noticable survival benefit... and then followed up by mentioning that it's happened on multiple seperate occasions in evolutionary history.
Heh.
fish used limbs in water well before animals used them to climb up on land.
Such a positive and evolutionary interpretation. It is far more likely that they used the arms to slug other fish.
Don't blame Durga. I voted for Centauri.
Hi. I'm Troy McClure. You might remember me from such fish-arm films as "Hugged by a Halibut" and "Atlantis Arm-Wrestling 2003"
an aquatic, salamander-like creature that would have pushed its arms downward to move through shallow rivers, and used them to prop itself up while waiting for prey or to get air.
sounds like a fish to me!If you get nervous, just remember that there are a few billion other people who don't really give a damn.
Evolution is NOT planned. It has nothing to do with intention. Suppose we lived in a world with increasingly intense sunlight (for whatever reason), so that the darker and thicker your skin/hair pigmentation, the more you resist exposure in the wild. If you have sensitive light skin, you'll get burns everywhere, which may perhaps develop into cancer. In 1000 years, when sunlight is extremely intense, most of the pale sensitive-skinned people are dead, while most of the dark tough-skinned are alive. Did anyone plan this? No. Did dark skinned people think "hey! I'm gonna start developing darker skin to survive better"? No. But the population has just "evolved" darker and tougher sun-resistant skin, like it or not, because the ones that didn't have it died off. It's as simple as that.
People only talk about evolution as a "shaping force" figuratively. It's in fact nothing but an observation about consequence. It's not some insidious super-power you can will.
"...multiple seperate occasions..."
Not just that, but _differently_ in each of the major eye types. There's no "animal eye", there are at least 3. (I forget exactly how they're categorised, but they're roughly vertibrate, cephalopod, and creepy-crawly.)
In particular, our retinas are 'back to front'. It's an flawed design, and that's why we have blind spots -- it's where the nerves leave the inside of the eyeball. If our eyes came about through _design_ then it was _crap_ design.
God-freaks can take the soft cheese out of their ears now.
THL.
Keeping
the epaulette shark:
p ro files/orectolobiformes.htm
http://www.elasmo-research.org/education/shark_
(scroll down)
It uses its limbs to "walk" around, and will even "walk" away when threatened rather than swimming (which would be faster, one thinks).
Corruptissima re publica plurimae leges.
As someone with eyes rated in the -2.25 diopter range, I'm kind of anxious for the day when you take a pill and grow new & improved eyes... when that day comes, I want the damn retina to plug in at the back.
Now it's fish with limbs.
Next they'll keep changing the channel and mucking with the volume.
kulakovich
OK, I shouldn't, but I'll bite. First, mutation is not the only (or even, necessarily, the most important) source of genetic change. Bear in mind that each individual has unique DNA. Normal variation is enough to drive a certain amount of evolution.
Second, your question about whether living on land is beneficial is incorrectly framed. It's not a question of "benefit". The question is, "Will this mutation give the individual's descendants a reproductive edge, however slight?" In the case of moving into a new ecological niche, the answer might well be, "Yes."
Your next layer of argument (mutation not surviving reproduction) is redundant. You have already eliminated harmful mutations; mutations that impair reproduction are by definition harmful. Nothing to see here except obfuscation; move along.
"The chances keep decreasing"? No, the cumulative effect is INCREASED. We're not talking about the likelihood of specific changes to one descent line; we're talking about changes that propagate laterally through a gene pool over time as new genetic combinations provide a reproductive advantage. The math is quite possible; I wouldn't call yours "impossible", just misapplied.
Finally, by what logic do you assert that the twisted bone or shortened muscle to which you refer does not make the specimen more likely to confer reproductive advantage on its progeny (NOT survival)? Your assertion is groundless and poorly stated. In fact, I can think of several ways this physical change could confer reproductive advantage. Perhaps your imagination is more limited. Regardless, the fossil record is full of species (up to and including our own) that found bone and muscle structures tuned to living on land to be useful.
I'd suggest you read some of Richard Dawkins' excellent writing for a better understanding of how evolution is thought to work. Have a nice day.
Corruptissima re publica plurimae leges.
Eugenics is one possible product of "Darwinism", but not the only possible product. If you consider "fitness" as "the ability to survive", that being the only logical definition in evolutionary terms, then "survival of the fittest" means "survival of those best able to survive". Belonging to a society that increases your chances of survival despite your genetic defects is an effective evolutionary strategy, the equal and opposite of eugenics. As long as the ability to treat and minimise the effects of these defects remains effective, eugenics is unnecessary.
Games Workshop Petition
"Permanent land-living animals took another 30 million years to develop into reptiles, birds and mammals, but what happened during that transition is unclear."
Birds didn't evolve, to our knowledge, for a LOT more than 30 million years after the Devonian. Late Cretaceous, 65 million years or so.
(IANAPaleontologist, but I wanted to be one when I was a kid, heh)
ERROR 144 - REBOOT ?
Not only that but there are at least 65 (yes, 65) phylogenetically distinct eye-forms. Wow - independant evolution 65 times.
see: Weiss, K. (2002). "How the eye got its brain." Evolutionary Anthropology 11: 215-219.
Cheers,
Simon
henry -- the human evolution news relay
Bzzzt! Wrong. I've let myself be trolled twice today, and my mouth is getting sore from the hooks, but I've got to correct your idiotic post.
First, "Darwinism/evolution" has no "natural (racist) conclusion of Eugenics". Evolution, as a theory - and if you can't handle what "theory" really means, go back to school, I don't want to get into it - describes how genomes change over time. Period. Like it or not, it's working on humans just as it works on every other living thing.
Second, scientists generally do NOT "have a hard time accepting" etc. Helping the poor is quite acceptable; they have not demonstrated a genetic disadvantage in reproduction. In fact, if they are reproducing at a greater rate than those who are not poor, they are demonstrating an advantage! Short term, I would think, but still an advantage.
As for birth defects, most are not carried into the next generation, being caused by either prenatal trauma (of one kind or another) or chromosome replication error. Most people with developmental disabilities, believe it or not, will have genetically normal children if they have any at all.
Close hospitals and ban free choice in human reproduction? What on earth makes you think this is part of the theory of evolution? I suppose some deeply twisted individuals might make a logically flawed argument that this is necessary, but I've never heard it advocated. Got a citation from a reliable source?
Now, personally, I'd like to see reproduction controlled, but only because there are too many people around already. However, that's irrelevant to the theory of evolution; we will be acted upon by selection pressure no matter what. It's the way things work. If we exceed our carrying capacity, a bunch of us will die; the survivors will be those whose genes (and memes, if you're into that kind of thing) confer advantage in that situation.
I'd like to see some kind of quote before I believe that Darwin "wholeheartedly believed in this sort of proposition"; I think that's complete hogwash, but I could be wrong. Again, got a citation from a reliable source?
"Rational believers of intelligent design theory"? Sorry, I don't think there IS a scientific theory of "intelligent design". A bunch of stuff promulgated by religious believers, yes, but I'm not aware of a scientific theory of that nature.
As far as "intelligent design" as a religious proposition (not scientific theory), I think you'd find that MANY scientists believe it to be quite compatible with evolution... the religious ones, anyhow. They just place the design further back in time - say, about 15 billion years further back.
Evolutionary theory describes a mechanism of great beauty and elegance; it's a shame that people's preconceptions often hide that truth from them. Still, if you can get past your prejudice long enough to read some good books on the subject, you might come away with a bit more appreciation for the subject.
Thanks for playing, have a nice day.
Corruptissima re publica plurimae leges.
What if natural selection does not improve the species? What if all living things were created in their best form, and have been heading downhill since then? Natural selection then plays the role not of improving a species, but of slowing its decline - such that if the power of natural selection was absent, the fall of a species would be hurried. Yet if natural selection was present, the species would still degrade, but at a much slower rate.
I have no idea who you are, so I'll try to be as cordial as possible.
You're completely misreading evolution.
Natural Selection doesn't try to DO anything. It's the name for a simple "phenomenon" - anything that survives 'til the opportunity to reproduce has some of it's genetic material passed down to the next generation.
There's no way anyone could construe Natural Selection in the way you're talking about. There's no "absense" of natural selection possible. If nothing survives, then quite simply, everything was "selected against", that is, it couldn't survive in it's current environment and didn't. End of story. If everything survives, then the current environment is safe until 'Time K', which is some time in the future when the Carrying Capacity [i.e., amount of our species the environment can sustain] of said environment has been reached.
Evolution happens, whether or not it's of divine design. Things were not *created*, they *happened*. DNA isn't that big of a coincidence when you consider the practical infinity of time and the practical infinity of the universe.
Your idea that things might have started off as "better" is bogus. The point of evolution is simple: The thing that survives moves on in the form of the gene.
First of all, you do not understand the theory of evolution AND you use "darwinist" in a way that does not reflect its true meaning.
Darwinist is in opposotion to Lamarckist, who was an evolutionary theory from before Darwin that postulated that the evolution of species was the result of adaptation made by members of the species in their life times (to Lamarck, if giraffes had long necks it was because proto-giraffes had had to stretch their necks to get to high branches and so their descendants had longer necks).
Darwin's theory was that natural selection of mutants was what shaped evolution.
If you assume darwinism, then it would be irrational to suppose that one human race is not inferior or superior to another.
Well, that might be what the grand wizard at your "racial pride" rally told you, but that is completly wrong.
If I take an Inuit and a Massai and switch them, they'll both be fucked. Because one is from a race that has adapted to the artic climate and the other to the savannah. Wich is the inferior one? The one that can survive in a cold hostile land or the one that can survive in a hot hostile land?
Races are not inferior or superior in an absolute sense, they are better adapted to specific situations.
If we are all the product of chance, then there is no good or evil.
Ah, yes, you're the type of person for whom the only reason not to hurt other people is the fear of hell.
So clearly, you do not reject darwinist evolution based on rational arguments, but based on irrational fears. Fear of what people would do if they didn't have the fear of hell in them...
To suppose that Darwinism doesn't lead to racism is the ultimate in willful blindness.
You retard. There was racism before Darwin, there was racism before the theory of evolution.
The bible promotes racism. There are the superior tribes, descendants of angels, and the others are inferior. God commanded the israelites to genocide at jehricho.
Stop trying to discredit things you don't like by linking them to things others don't like.
You absolutely, necessarily, have to be racist to be a Darwinist.
You absolutly, necesserily have to be a racist to believe in god, because god is racist.
You cannot have every group survive, because some must fail.
Again, wrong because you do not understand the theory of evolution and the darwinist theory of survival of the fittest.
As long as there are enough ressources, all groups can survive. There is no magic need for one group to diappear.
The point is that there is no good or evil, and that we can't trust the convictions of our mind if we assume Darwinism.
That's nihilism, not darwinism.
And you should never trust the convictions of your mind.
You can't take the sky from me...