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Further proof of Evolution? 4-finned dolphin....

  • Thread starter Clint
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Clint

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A dolphin was found with 4 fins. Scientist believe it could be ancestral dna.

4-finned dolphin
 
We have already observed vestigal bones in fins. In whales, which are presumed to have come from land animals, we can see the vetigal remnants of bones much like the structure of our hands. This is an interesting article, however. Thanks for posting.
 
The article says fossil evidence points to a common ancestor between porposises and deer, but I was previously under the impression that porposises were closer to the felines in descent. Anybody know which possibility has more clout?
~Joe
 
Hehe, I made sure to put a question mark in an attempt to not start a flame war. I learned that trick from CNN.

I can hear it now..

"CNN has a liberal bias and only tells half the story blah blah blah!!! "
 
This doesnt prove evolution, but it showes that theirs chance for mutation, theirs alot of gaps in Evolution, but theirs alot of gaps in every thing...
 
Yeah yeah, I know. But it does help strengthen the theory.

What they are saying isn't that this is a mutation. They are saying that fossils show dolphin/whale like animals with 4 fins, and this live animal shows that perhaps the dolphin could have evolved from them. I know they did because Evolution makes perfect sense to me.

When I was a christian i thought that evolution was gods way of making everything and the genesis story was a metaphor.
 
[b said:
Quote[/b] ]The article says fossil evidence points to a common ancestor between porposises and deer, but I was previously under the impression that porposises were closer to the felines in descent. Anybody know which possibility has more clout?

Well...it's complicated. They did evolve from an ancient land carnivore, but not from a member of order Carnivora. Way back when, there was a group called the Mesonychids, which evolved from ungulates such as deer, but were carnivorous. Some were roughly wolf-sized, with more elongated skulls and cat-like tails, while the largest, Andrewsarchus, was significantly larger than a kodiak bear, with a skull well over 4 feet long.

In recent decades, the fossil record of whale evolution has become much clearer, with literally dozens of steps between mesonychids and modern whales and dolphins being discovered. Wikipedia has a good layman's version, with more detail (but still at the public level) in Carl Zimmer's book At the Water's Edge. Whale evolution on wikipedia.

The link between whales and mesonychids is pretty much solid at this point, though there's some quibbling about whether it might have been a poorly-know sister group to the mesonychids, IIRC. It wouldn't be paleontology without quibbling.

[b said:
Quote[/b] ]This doesnt prove evolution, but it showes that theirs chance for mutation, theirs alot of gaps in Evolution, but theirs alot of gaps in every thing...

Nope, it doesn't; we've proven evolution long ago. This is just another drop in the ocean of evidence.

[b said:
Quote[/b] ]What they are saying isn't that this is a mutation. They are saying that fossils show dolphin/whale like animals with 4 fins, and this live animal shows that perhaps the dolphin could have evolved from them.

Well, it's complicated (just about every answer in science involves that phrase).

Genes don't just make structural protiens; they also control the expression of other genes, which may in turn control the expression of yet more genes, and so on and so forth. It is entirely possible to lose a structural trait, such as limbs, not by loss of the limb genes, but by the loss or change in activity of the genes that turned those genes on in the first place.

What I suspect happened in this case is that this dolphin had a mutation to the genes which controled limb development, activating limb genes that had really been there the whole time but where never activated in other dolphins. This has happened multiple times in whales as well, and we recently managed to get chickens to grow teeth by the same mechanism: restoring the signal that activated the tooth genes hidden the whole time. In what should be totally unsurprising, the chicken teeth formed in a manner seen in only one other group: archosaurian reptiles (a group including modern crocs and the extinct dinosaurs).

I'm really unsurprised, but I think it's *very* interesting for another reason: Gray's paradox. The first scientist to study animal locomotion, Gray found a simple scaling in how much drag fish are subjected to, but when he did experiments on a mock-porpoise, he got turbulent flow, massively increasing the drag. We know from data on how fast dolphins swim that they *must* have a method of laminarizing the flow around them, and this has been extensively studied. But here we have a dolphin with two protrustions that would *seriously* disrupt flow around the body. I want to see how fast this thing can swim, and what the flow looks like. It's possible that hind-limb loss in dolphins may be their solution to Gray's paradox, and that this individual can prove that by showing that limbed dolphins generate turbulence.

Overall, though, it's not really surprising. These sorts of things are commonplace, just not in species that are cute and fuzzy and therefore get major media attention.

On a similar note, horses born with 3 toes, like their ancestors, are actually also well known. It's said that Alexander the Great rode one, believing it to be good luck.

Mokele
 
We have PROVEN evolution? How? When?

Where was I? (don't say it!)
 
yea I dont know when they proved it, thats like saying something dasterdly obsured like nepenthes suck!

(lol just kidding)
 
  • #10
[b said:
Quote[/b] ]Hehe, I made sure to put a question mark in an attempt to not start a flame war. I learned that trick from CNN.

Judging by the following post, it looks like maybe you should have added in a few extra question marks.
smile_n_32.gif
 
  • #11
I am with Mokele.  I believe evolution has been proven for a long time.  Those indeviduals that feel they are too good to be decendant from apes or ape like creatures just irritate me.  We have found the missing link that apes and humans decended from a common ancestor.  The aminal split up into 3 different branches of the family tree.  One going to the apes, one going to neadertal, and one going to homo erectus.  (I hope I got those right)  Then further down the tree erectus and neadertal hybridized and became one group again.  The neadertal(sp) features are seen in some indeviduals today.  The protruding forhead and eyebrows to be one of them that comes to mind.  I know someone with those features.  It makes sence that the neadertals didn't die out like previously expected.  They were stronger and taller than other humanoids of the time, and just as smart.  There brain sizes and the fact that they also used tools points to that.  It never made sence that they would have just died out.  According to a show on cavemen scientist now believe they didn't die out, but intigrated with homo erectus ( I sure hope that was the correct species.  Anyway I think you get the jist of what I am saying)

So I stand firmly that evolution has been prooven beyond a reasonable doubt to be True.  The "Faithful" that believe they were the begining of the blodlines have no proof to stand there ground.  Inteligent design holds no water either.  It is not as simple as reverse engineering the cilia motor of a bacteria to prove inteligent design.  Evolution can have many intermediate steps that are unseen or it can make leaps from one stage to the other rather drasticly with major mutations.  You cannot say that the cilia motor of a bacteria is too complicated to be designed by evolution.  There argument is that if you remove one component of the motor it does not work so if evolution slowly adds one peice to the motor every mutation and the motor is useless without all the parts then it had to be designed that way because natural selection would not have kept the motor around long enough for it to have been finished by evolution.  That is why I say evolution can happen in leaps.

Since we do not know the full workings of how DNA functions, we cannot fully understand the minute workings on evolution.  Like Mokele said manipulating one gene can affect manydifferent things.  Since one singel gene can affect expression on one or more different genes, and different combinations can affect many different aspects of developement.  So realy all a mutaion had to do was change one gene and Bam everything falls into place for the cilia motor to be formed.  Then that gene is kept because it helps the species like natural selection says.

Then you also have to look at this.  Evolution does not always keep the good trates over bad ones.  Sometimes undesireable trates are kept or conditions change making the kept evolutionary changes obsolete.
 
  • #12
Well,if we evolved from apes/ape like creatures why would apes/monkeys still exist?It would seem that they would have evolved to.Just my 2 cents.


Jerry
 
  • #13
That's what people don't understand. We shared a common ancestor, not that we evolved directly from apes. They branched off from this ancestor, which has long ago died.

-ben
 
  • #14
Jerry you are correct they did evolve.  They evolved into the current day apes we know of.  It is like coming to a fork in the road.  Part of out ancestors down one fork turning eventualy into humans and the others went the other way turning slowly into current modernday apes.  Each path on the evolutionary trail leads to different evolutionary changes.

Are you also aware that all dogs came from a singel ancestral bloodline?  All the different breeds of dogs we have today came from selective breeding to get the different breeds.  So now they all look different.  That is the same things that happened with our ape ancestors.  Some stayed in the trees and others evolved into man.

ALso there is a difference between apes and monkeys too.  Just FYI  We are not related to the spider monkey and other monkeys.  We are related to the great apes like erangatang(sp) and gorrillas.  They just took a different road on the evolutionary path.
 
  • #15
@Cool85k5

Not true. Different groups of apes have been subjected to different selection pressures. Some are subject to competition via different other species, leading to certain groups having some, extreme, or no character displacement, yadda yadda.

I agree with Mokele too...evolution (especially through mutation) was proven a looooong time ago.
 
  • #16
What I find many people do not understand is that the things here today are not the same as they were back when the road split. So everything does evolve at the same time. The current version of apes are just related to us. They are not us. There ancestors are the same as ours, and those have long since been extinct. I find that many people think we evolved from current day apes and that is false. We evolved from past day apes. The same apes that the current day apes evolved from.

I was lucky to have had a professor that also tought a class in evolution when I took BIO.
 
  • #17
Evolution does exist and it must for the survival of life on our continuously changing Earth. However evolutionists get confuzzled between what is evolution and what is creation. In order for something to evolve it must first exist (or be created). Correct me if I'm wrong but when a species evolves, the specie that doesn't dies off. Survival of the fittest if you will.

Sure we might have similar DNA to [insert monkey specie here] but you're jumping way too many conclusions if you believe we came from a monkey. It is also pretty far fetched if you believe all life on Earth evolved from a one celled thing in the ocean billions of years ago. Perhaps if all life were some type of plant or fish with little variances the theory that we all evolved from something would satisfy. But the fact of the matter is in my logical opinion and beliefs all species were created (however which way you believe), I believe God created everything. Evolution is just another phenomenon God created in order to sustain life on Earth.
 
  • #18
[b said:
Quote[/b] ]We have PROVEN evolution? How? When?

Oh, years and years ago, long before any of us were even born.

Evolution = change in allele frequency over time. This has been observed many, many, many times in the lab and in the wild, to the point that doubting it occurs is just stupid.

Natural selection = unequal propagation of genotypes. Once again, this has been observed so many times that claiming it does not exist is ridiculous.

Speciation = the separation of gene pools. Not as frequently observed, but still common; scientific discoveries of new species evoling from existing ones are now so common they're relegated to 3rd rate journals. It's so common it's boring.

Adaptation (noun) = a variant of a trait which confers a fitness advantage over alternative forms of the trait. Again, so common as to be dull.

Adaptation (verb) = the spread of an adaptation by natural selection. Again, dirt common.

What all of this boils down to is Gould's famous elaboration that evolution is both a fact and theory.

The fact of evolution is the process we see going on around us in nature and in the lab. The theory of evolution is the mechanisms we use to explain what we see (heritable fitness variations spreading through a population). The fact of evolution is "The allele for such-and-such disease resistance has spread through frog population A...", while the theory is "...because the allele conferred a heritable fitness benefit and thus was acted upon by natural selection".

It's like gravity. There's the fact of gravity (I drop things and they fall according to certain equations) and then there's the *theory* of gravity (gravity is caused by deformations in the space-time continuum / by gravitons / by superstrings). One is the fact, the observable occurence, the other is the explanation, why that occurence happens in the first place.

I would like to note, with no small degree of satisfaction, that due to the failure to produce a Unified Field Theory and the impending demise of M-theory, we actually have a better understanding of the theory of evolution than we do the theory of gravity.

To repeat: we are more sure of the mechanisms by which species evolve than we are of the mechanisms that keep you from simply floating away.

[b said:
Quote[/b] ]Since we do not know the full workings of how DNA functions, we cannot fully understand the minute workings on evolution. Like Mokele said manipulating one gene can affect manydifferent things. Since one singel gene can affect expression on one or more different genes, and different combinations can affect many different aspects of developement. So realy all a mutaion had to do was change one gene and Bam everything falls into place for the cilia motor to be formed. Then that gene is kept because it helps the species like natural selection says.

While that is possible, actual empirical evidence points to a different mechanism: exaptation.

Exaptation is the process by which a trait, formerly selected for one reason, becomes 'co-opted' into a new task and is selected and modifed to those ends.

The bacterial flagella is actually an excellent example of that: we have an intermediate, and it's not a flagella - it's a toxin-injecting device. These devices are built with *mostly* the same genes, in *mostly* the same pattern as the bacterial flagella, but serve a totally different purpose, boring into other cells to kill them, so the bacteria may feast on the remains. there are numerous stages of this toxin pump. It appears that what happened was that bacteria evolved a boring needle, but then mutations allowed it to become a propulsion device.

[b said:
Quote[/b] ] It makes sence that the neadertals didn't die out like previously expected. They were stronger and taller than other humanoids of the time, and just as smart. There brain sizes and the fact that they also used tools points to that. It never made sence that they would have just died out. According to a show on cavemen scientist now believe they didn't die out, but intigrated with homo erectus ( I sure hope that was the correct species. Anyway I think you get the jist of what I am saying)

Actually, it's throught they merged with our own species, Homo sapiens. Also, their intelligence is still up for debate: the total brain volume was larger, but they had a smaller frontal lobe (thinking) and larger occipital lobe (vision). Better hunters, perhaps, but unlikely much smarter.

[b said:
Quote[/b] ]ALso there is a difference between apes and monkeys too. Just FYI We are not related to the spider monkey and other monkeys. We are related to the great apes like erangatang(sp) and gorrillas. They just took a different road on the evolutionary path.

Technically speaking, all life on earth is related; it's just a matter of how closely. But you're mostly right.

Humans are most closely related to chimps & bonobos, then next gorillas, then orangutans, then gibbons (the 'lesser' apes). The apes as a whole, including us, are most closely related to Old-World monkeys, and the combined group of Apes & Old World monkeys is most closely related to New-World monkeys. From there on it's the various prosimians such as lemurs, aye-ayes, potos, and that lot.

That was annoying to type; one of these days, I'll invent some sort of Java code or something that can automatically generate phylogenetic trees that can be posted in this manner.



Anyhow, if you want to prove evolution yourself, send away for two sets of fruit flies; white eyed and red-eyed. Start with an equal mix. Every generation, kill half the red-eyes. After many generations (which, in fruit-fly terms, is about 2-3 months), you'll have only white-eyed flies. Even if you start with 100 red-eyes to 1 white-eye, the result will be the same, though it'll take longer. That's all evolution is; the animals with genes that promote survival (or avoid death) breed more, and become an every-increasing part of the population.

Mokele
 
  • #19
Sir read my post I did not say we came from a monkey we came from APES. There is a big difference!

I would beleive that IF we all were made from different building blocks, but that is not the case. We are all made from the same building block of amino protiens and molecules.

Your also must not have a grasp of how long billions of years is. Humans have only been here for a speck on the time line of how long the earth has been here. There has been plenty of time for a colony of single celled organism to evolve into the diversity of life we have on earth now.

Evolution happens in leaps at time remember? Therefor it is possible for (one) single celled organism that devides by celular devision to mutate as it devides giving you two different cells. (because of the mutation) then those two different cells devide giving you two distinct single celled organisms. Then one of those mutates and the variation becomes exponetial. Leading to multicelled organisme that further mutate over millions of years. Even a million years is a drop in the bucket when you compair to billions of years.

I find that those people who are religous and believe in creation use an excuse like this.
[b said:
Quote[/b] ]I believe God created everything. Evolution is just another phenomenon God created in order to sustain life on Earth.

It used to be thought that when a bad person got sick it was Gods will that that person was sick. Then Doctors came along and now it is Gods will that the medical professionals save that person. Sorry I don't buy it. It is my opinion the excuse "it is Gods will" is the voice of ignorance that does not have the answers and it give people a way to explain what cannot be explained at this time. Instead of trying ti figure it out, many people are duped into believing an adiquated explination.
 
  • #20
Yeah, the pressures at one point probably caused some distant ancestor of the dolphin and some other mammal (which became land dwelling 4 legged-s) to split. Evolution could have been due to climate change, geographical/ habitual/ sexual isolation that causes the genes of ancestors to progress along differently in their new habitat. Evidence lies in as far back as organisms go. That is probably why apes aren't changing into humans (that old story...) today, because the selective factors don't require them to. They're doing just fine in the trees.

There are many basic homologous structures in our ancestors which have adapted (adaptive radiation?) to form the fins of dolphins, leg of a man, hind leg of a horse etc etc. What you are seeing in there is probably a repressed gene coming out because of some weird external factor. Like some of the others have said it would be interesting to see how it fairs in the wild.

J
 
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