Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: Kosh on August 25, 2009, 11:00:23 pm
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A real Jurassic Park in the pipeline? (http://www.physorg.com/news170426405.html)
Hans Larsson, the Canada Research Chair in Macro Evolution at Montreal's McGill University, said he aims to develop dinosaur traits that disappeared millions of years ago in birds.
Larsson believes by flipping certain genetic levers during a chicken embryo's development, he can reproduce the dinosaur anatomy, he told AFP in an interview.
Though still in its infancy, the research could eventually lead to hatching live prehistoric animals, but Larsson said there are no plans for that now, for ethical and practical reasons -- a dinosaur hatchery is "too large an enterprise."
"It's a demonstration of evolution," said Larsson, who has studied bird evolution for the last 10 years.
"If I can demonstrate clearly that the potential for dinosaur anatomical development exists in birds, then it again proves that birds are direct descendants of dinosaurs."
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Hans Larsson, the Canada Research Chair in Macro Evolution at Montreal's McGill University, said he aims to develop dinosaur traits that disappeared millions of years ago in birds.
I half expected that to continue...
"And now, he is Pterodactyl Man! Forever watchful with his mutant reptilian eyes for evildoers!"
Other than that, interesting stuff :)
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Okay. Hang on.
Evolution is not directional. Defined at its simplest, evolution is simply a change in allele frequency in a population over time (if I recall correctly.) This is something a lot of people (including most of the anti-evolution blowhards) don't understand: evolution does not imply 'progress', it does not imply motion in a particular direction. What this guy is doing is more of...genetic archaeology?
There's got to be a better term for this.
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Agreed, even scientists fall into that particular trap occasionally, of thinking of Evolution as 'ongoing improvement', rather than 'ongoing adaptation', it because of a perfectly natural tendency, even in science, to place ourselves as the ultimate outcome of it, even though we are not the newest species on the planet.
I suppose, from a presentation point of view, it's an accurate description of what he is doing, he's attempting to re-activate genetic traits that were active in our past, however, that doesn't mean they'll never active again in the future, so possibly even genetic archaeology might be misleading, I suppose, if I were to be anal about it, the most accurate description would be something like Latent Gene Investigation.
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Quite a bit of this kid of work has already been done in the lab. Chickens with teeth, birds with scales instead of feathers etc.
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I have my reservations that you could ever get anything that was a 'real' dinosaur out of the research to be honest. some cellular structures will get recombined with others and start performing completely different tasks during the course of evolution, I'm really not sure you could really reset everything to the situation they were in 65 million years ago, some of those 'levers' may well be extremely hard to find.
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Well the one thing they do have going for them is the discovery of soft tissue inside of fossils containing partial DNA from actual dinosaurs. They find enough of that and they would have a blueprint to go by.
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So long as in the post-apocalyptic Wild West I can ride my steel-plated T-Rex into battle wielding a flame thrower, I'm good...
-Thaeris
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Quite a bit of this kid of work has already been done in the lab. Chickens with teeth, birds with scales instead of feathers etc.
Can anyone say "Greasel"? (http://www.youtube.com/watch?v=DIbrQYrXhdI)
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I demand scaly chicken teeth pics :lol:
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I for one welcome our Chickensaurus Rex overlords.
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Okay. Hang on.
Evolution is not directional. Defined at its simplest, evolution is simply a change in allele frequency in a population over time (if I recall correctly.) This is something a lot of people (including most of the anti-evolution blowhards) don't understand: evolution does not imply 'progress', it does not imply motion in a particular direction. What this guy is doing is more of...genetic archaeology?
There's got to be a better term for this.
It's still going in reverse because they are taking something and reverting it BACK to the form it previously evolved from. Personally I think that compared with the Mesazoic, life is quite a bit more boring than it was.
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I do believe there is actually a scientific theory about that Kosh, that the more 'radical' type of life is too fragile to environmental change, so as evolution passes (I recoil from using the word 'progresses') the gene-pool gets cleaned of the edges, so life is more resilient, but not as experimental in nature.
Once again, I'm loathe to personify nature by saying it learns from its mistakes, but there is a natural tendency for this sort of thing to happen in systems, chaos spawns organisation at some point, even if the chaos is still present.
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Well, highly specialized species end up struggling when their specifically suitable environment changes. Of course this holds true for all species - change equals strife and the fastest adapting species will flourish - but for species that are so dependant on some feature of their environment, changes can be all that much more swift in ending the species.
Good example would be polar bears as opposed to normal bears. Polar bears have adapted to life at polar maritime regions in a way that requires perennial sea ice. If that changes, polar bears go bye bye unless the change happens very, very gradually and some polar bears simply change their ways so that they can produce offspring without sea ice coverage.
Another historical example would be wool mammoth, although controversy exists as to whether it was hunted to extinction or if it simply didn't have time to adapt to the warming climate.
Yet another example of very likely irreversible evolutionary path would be the cetaceans. They started as quadruped land animals and ended up with behemoths almost completely adapted to living in oceans, and for them to become capable of land life again they would need to first of all develope a mutation that makes their hind legs grow back, then reduce their size and go through some immense skeletal and morphologic changes for them to step away from water. It's very difficult to see that happening within normal evolution.
Besides regarding feathers and dinosaurian/avian features, isn't it at least a very credible possibility that part or even majority of dinosaurs were feathered to begin with? Making scaly birds sounds more like kickback to reptilian ancestry rather than dinosaurian. Now, make me an ostritch that has teeth, tail and arms that it can use to grab stuff... and I'll say it is a dinosaur.
Of course, I consider all avian species to be higly specialized branch of dinosaurs and only named differently due to historical reasons...
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I suppose, at least with Cetaceans, water is a pretty safe medium to make that kind of evolutionary commitment in, evidence suggests atmosphere and land masses change far more frequently and profoundly than the composition of the Ocean. It's certainly had the same level of salinity for an extreme long time.
I'm still not sold entirely on the feathered dinosaur idea, I can accept that certain branches of the family developed feathers, and that branch was better adapted to surviving the post dinosaur environment (possibly because of the extra warmth provided by the feathers?) and developed into birds, but I suspect they were more the exception than the rule at the time.
Problem is, when looking back 97 million years, it's kind of uncertain we will ever know for absolute certainty. I know certain amber-trapped specimens etc have suggested feathered dinosaurs, but from what I understand the finds seem to be centred in China, whereas European and American dinosaurs show far fewer bird-like qualities?
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I heard from Paul Serrano, a fairly big archaeologist, that he believes all dinosaurs were feathered - but I think it was just a hunch.
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I know there have been fossil impressions of scaly dinosaur skin, so I'd say it's a safe bet that at least some of them looked like the pop-culture imagery.
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I do recall, some years ago, that there was experimentation into the pigmentation of Dinosaur skin and it was suggested that there was a strong possibility they were much more brightly coloured than the traditional greys and greens, with markings more akin to tigers or the more colourful lizards.
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Of course, I consider all avian species to be higly specialized branch of dinosaurs and only named differently due to historical reasons...
That's what I was taught in college: That birds are considered to be living dinosaurs. I remember it was confusing because there were the ornithischians, meaning "bird-hipped," and the saurischians, meaning "lizard-hipped," but birds actually evolved from the latter group.
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I suppose, at least with Cetaceans, water is a pretty safe medium to make that kind of evolutionary commitment in, evidence suggests atmosphere and land masses change far more frequently and profoundly than the composition of the Ocean.
Megalodon might have something to say about that.......
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Well, the Megalodon is only about 1.5 Millions years extinct and were mostly killed off by geographic change cutting off its food supply, as well as climactic upheaval nowhere is totally secure, and larger creatures are dependent on sea temperature to a higher degree, that's why the largest sea-creature in the modern world regulates its own heat, because it's a lot better at coping with temperature changes.
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And here I thought this was about urbanization and people doing more work in sitting position :lol:
As a thought experiment, if current development towards sitting work continued, what would be the most likely adaptive step human body would take? Weaker lower limbs? Curved back? Smaller frame? Decreased brain volume?
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I'd say, in general, an increase of Intelligence and Dexterity, but you'll probably lose some Strength and Endurance points. ;)
In truth, it's difficult to say because mankind does such a vast variety of things, sitting in a chair all day won't really do much to affect evolution on a global scale, because somewhere there's a guy wrestling sharks. I think an increase in brain size is likely, and an increase in Dexterity, those two aspects together are the real tools we've used to make every other tool, and, coontrary to popular belief, we as a race enjoy exercising our minds, and our ability to create, to degrees far beyond any other species. However, our concept of laws and social structures that go against our own primal 'conditioning' means that for humanity, natural selection doesn't really apply in the same way.
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If it doesn't affect reproductive fitness, it's not likely to cause any changes.
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That's the thing, our way of laying out society means that our reproductive fitness is increased, in a way, almost every male/female in the species gets an opportunity to reproduce, there's no mentality as there is with many pack-forming animals of a single dominant male who gets the mating rights. So because that structure changes the variables somewhat, it makes it a lot harder to make any kind of guess as to our evolutionary path.
Edit: Basically, we've removed to a large degree, natures way of removing genes that are not advantageous at the time, whether that's a good or a bad thing is something only time will tell, I guess.
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Oddly, sexual selection in evolution is generally driven by female choice; male power is the exception, not the rule. (Just an interesting note.)
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Oddly, sexual selection in evolution is generally driven by female choice; male power is the exception, not the rule. (Just an interesting note.)
That's why I think we could learn an awful lot from Bonobo monkeys, not only do they have a Matriarchal structure, but they also employ similar breeding philosophies to humans some ways, there is far more diversity in their mating habits and choices, which is a trait that very few species share with humans. I think they'd give us some good clues to the path we took at the very least.
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I've only heard of 2 human traits that can be proven to be evolving since humans started the whole civilization thing.
1. Men are getting bigger, the average ancient male Egyptian mummy was 5'2" compared to today the average has got to be close to 5'10"?
2. Women are getting thinner and more attractive. I recently heard of a study that shows women who are considered attractive are more likely to have multiple children and more likely to have baby girls, opposed to baby boys, who will be more likely to grow into attractive women and continue the cycle. The thinner thing can be explained partially by cultural pressure, but its a pressure thats been around for a few generations and seems to be catching on in a genetic way.
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Don't...think that's true. Notions of attractiveness change considerably with time, much more than phenotype does. The Rubenesque woman used to be considered the ideal.
Men do prefer a specific waist-to-hip ratio in women which I believe has remained fairly constant.
Men and women are getting taller, but that's up to better nutrition, in no small part. Don't know how much of that is genetic. Would want MP-Ryan to comment.
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When I said attractive I wasn't talking about size. There certain facial features, body shapes, lack of hair in certain areas, skin health and symmetry that have always been part of female attractivness. I qualified my statement about size.
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Symmetry, a point-seven waist-to-hip ratio, and skin health are evaluated in sexual selection - two of those traits for men and women. I see no reason why women would be getting more attractive any more than men would, though. Data?
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http://www.timesonline.co.uk/tol/news/uk/science/article6727710.ece (http://www.timesonline.co.uk/tol/news/uk/science/article6727710.ece)
not the particular story that read about the study but all the major points are there.
Basically says men only want a hotty while women consider more factors when choosing a mate.
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There's a lot of junk reporting and oversimplification in that article.
Even he, however, might have been surprised by the subtlety of the effects now being detected by researchers looking into human mating.
This, for instance, is garbage; Darwin wrote about sex selection quite extensively.
Moreover, the article fails to make the fundamental tenet of sex selection clear. People are not becoming more beautiful because beautiful people have more children; people are beautiful because they're genetically inclined to have more children. What we perceive as 'beauty' is a set of phenotypic signposts for reproductive potential and good health.
Reading that article, one might conclude that the beautiful people are getting more action and having more babies, but the opposite is (sorta) true; people who have healthy children tend to appear beautiful.
And this quote in the last paragraph
“For women, looks are much less important in a man than his ability to look after her when she is pregnant and nursing, periods when women are vulnerable to predators. Historically this has meant rich men tend to have more wives and many children. So the pressure is on men to be successful.”
is unsubstantiated evopsych bull****. There are no testable predictions in that statement; it's an evolutionary just-so story.
In short, be deeply suspicious of articles like this in popular outlets. Although they do often get at some interesting points, they're generally misrepresented, oversimplified, and sexed up, giving credence to a lot of the crap postulates that evolutionary psychology has produced.
(This is not to say that the science of attractiveness is invalid. There are dozens of studies that objectively measure what people find attractive, and it tends to focus on symmetry and certain proportions. However, to assert that people are more attractive now than they were fifty, a hundred, or five hundred years ago is a deeply dubious assertion, because there's little way to untangle the genetic changes from all the changes in health and nutrition that have occurred.)
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you could test it to see if it's predictions are true. like rich men having more children and poor men having fewer.
oh, wait...
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Well, that creativeness has allowed us access to contraceptives etc, so it's difficult to do a direct comparison.
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you could test it to see if it's predictions are true. like rich men having more children and poor men having fewer.
oh, wait...
Funnily enough, that leads to an interesting thought - since it's the poor people in this world who tend to have the most children as well as endure the most evolutionary pressure, does this mean that the poor sections of society will continue to evolve while the rich people's gene pool stagnates? (Assuming that scientists don't figure out in the near future how to modify genes on demand and take over from natural selection, which would cause the rich gene pool to change rather rapidly.)
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I realize this is anecdotal but... I see PLENTY of ugly people around here having kids... ;)
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you could test it to see if it's predictions are true. like rich men having more children and poor men having fewer.
oh, wait...
Funnily enough, that leads to an interesting thought - since it's the poor people in this world who tend to have the most children as well as endure the most evolutionary pressure, does this mean that the poor sections of society will continue to evolve while the rich people's gene pool stagnates? (Assuming that scientists don't figure out in the near future how to modify genes on demand and take over from natural selection, which would cause the rich gene pool to change rather rapidly.)
On the other hand life expectancy is significantly lower, and only child mortality is obscenely high, at least in the poor countries.
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you could test it to see if it's predictions are true. like rich men having more children and poor men having fewer.
oh, wait...
Funnily enough, that leads to an interesting thought - since it's the poor people in this world who tend to have the most children as well as endure the most evolutionary pressure, does this mean that the poor sections of society will continue to evolve while the rich people's gene pool stagnates? (Assuming that scientists don't figure out in the near future how to modify genes on demand and take over from natural selection, which would cause the rich gene pool to change rather rapidly.)
The idea that humankind has stopped evolving is a bit silly. Allele change is actually proceeding more rapidly than ever due to a lot of 'interracial breeding' (races don't exist on the biological level). So to say that some will 'continue to evolve' while others won't is a bit odd, since access to a wider pool of mates is making the human population evolve faster than ever.
Whether natural selection is at work is another matter entirely, however.
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Assuming the more active humans among us succeed in breeding more by getting up off our butts, going out and meeting women and generally keeping trim. Doesn't that negate the withered leg avenue?
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The idea that humankind has stopped evolving is a bit silly. Allele change is actually proceeding more rapidly than ever due to a lot of 'interracial breeding' (races don't exist on the biological level). So to say that some will 'continue to evolve' while others won't is a bit odd, since access to a wider pool of mates is making the human population evolve faster than ever.
Whether natural selection is at work is another matter entirely, however.
Your last sentence is the key, though. For evolution to occur there has to be an overall genetic drift at the species level. Without natural selection (or artificial selection) people will keep mixing up alleles, but the frequency with which alleles occur will not change significantly. All I meant in my previous post was that selection seems to be more prevalent among poorer nations and neighborhoods, and when combined with the fact that these poorer people also tend to have the most children (some developed countries barely produce enough children to replace the previous generation), this suggests that evolution could proceed more rapidly there.
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No, you're misunderstanding. The frequency of alleles in the human population as a whole is changing more rapidly than it has in the past (not merely 'mixing about'). This is the definition of evolution. Ergo, our species is evolving faster than it ever has.
The selection issue is a dubious one and I've seen no data that really studies it. The idea that poor people would somehow 'evolve faster' than the 1st World rich suggests a belief that 'evolving' is a good thing that makes people more attractive and intelligent. If anything, selection pressure in those countries would favor resistance towards disease and the ability to survive on a restricted diet. We're not likely to see Homo Superior suddenly popping up in Somalia or whatnot. Evolution is adaptive, not directional.
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Reverse evolution?
(http://hydrodictyon.eeb.uconn.edu/courses/EEB210/evolution.jpg)
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Surely devolution is a more appropriate term.
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Well, that creativeness has allowed us access to contraceptives etc, so it's difficult to do a direct comparison.
True, but humans have been using contraceptives for thousands of years. 3000 years ago ancient egyptians used crocodile dung as spermicide.
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Well, that creativeness has allowed us access to contraceptives etc, so it's difficult to do a direct comparison.
True, but humans have been using contraceptives for thousands of years. 3000 years ago ancient egyptians used crocodile dung as spermicide.
Dear lord no
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Well, that creativeness has allowed us access to contraceptives etc, so it's difficult to do a direct comparison.
True, but humans have been using contraceptives for thousands of years. 3000 years ago ancient egyptians used crocodile dung as spermicide.
Dear lord no
How does someone come up with that? "Oh wow, when i smear croc **** on my dong, I don't have kids!"?
How do you even get any woman in any time period to even approach you when there's reptile feces on your wiener?!
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Well, that creativeness has allowed us access to contraceptives etc, so it's difficult to do a direct comparison.
True, but humans have been using contraceptives for thousands of years. 3000 years ago ancient egyptians used crocodile dung as spermicide.
Dear lord no
How does someone come up with that? "Oh wow, when i smear croc **** on my dong, I don't have kids!"?
How do you even get any woman in any time period to even approach you when there's reptile feces on your wiener?!
Do we know thats how it worked? :P
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Maybe they jammed it up there afterwards......
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Well, that creativeness has allowed us access to contraceptives etc, so it's difficult to do a direct comparison.
True, but humans have been using contraceptives for thousands of years. 3000 years ago ancient egyptians used crocodile dung as spermicide.
Dear lord no
How does someone come up with that? "Oh wow, when i smear croc **** on my dong, I don't have kids!"?
How do you even get any woman in any time period to even approach you when there's reptile feces on your wiener?!
Do we know thats how it worked? :P
You have a good point there. It'd probably be a killer contraceptive, because no woman would want to be in the same room as you if you used it. :D
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You guys have it backwards; they were apparently used in pessary form. The women inserted them.
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You guys have it backwards; they were apparently used in pessary form. The women inserted them.
Again, i must ask, what was the first woman thinking who decided it was a good idea to shove gator poo in her cooter
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Probably the ancestor of a certain tub-related girl. But enough about that, enough about Gator poop.
More about the odds of us evolving into Morlocks :yes:
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For that, we'd need hundreds of generations of selective breeding and/or genetic engineering.
Wasn't this thread about tricking bird DNA into expressing old unused bits of genetic code, causing them to display dinosaur characteristics?
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Yas......
(http://farm4.static.flickr.com/3167/2742531590_4d4b0ef746.jpg?v=1218142758)
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Well chickens and other birds legs are already scaly and their feet have the same general look of some
dinosaurs(T-rex).
edit: My question is how much will a chickenosaurus cosst as a pet?
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No the real question is will it taste like chicken?
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Colonol Dekker said:
Assuming the more active humans among us succeed in breeding more by getting up off our butts, going out and meeting women and generally keeping trim. Doesn't that negate the withered leg avenue?
But is it enough to overcome the dwindling averages? Some statistics show people are actually moving and having any sort of physical activity less and less. While there are people who still exercise a lot, I find the number of them is relatively small compared to general population.
Also, what thing would support that human would become more dexterious?
As a general question, what kind of adaption in the human spine would need to happen in order that the sitting position would not stress it so much? I guess that's where we would be heading.
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DO THE ROOSTERSAURUS REX HAVE LARGE TALONS?!!
(http://i28.tinypic.com/2ypkz61.jpg)
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DO THE ROOSTERSAURUS REX HAVE LARGE TALONS?!!
(http://i28.tinypic.com/2ypkz61.jpg)
LOL that's funny, but it appears to have 5 limbs?? Two legs, two wings and one arm???
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I believe that 'arm' is the other leg, curled up.
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Doh! Of course, it just looked too far up the body at first to be the leg.
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... Then where did you get the second leg from?
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He expected two legs on the ground so he saw two legs o the ground. Same for me. :<
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He expected two legs on the ground so he saw two legs o the ground. Same for me. :<
Yeah, just one of them tricks of the mind, I "saw" the other leg behind the first. Sorry about that Slayer! :nervous:
:sheepish:
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Hmmm. Human mind. Like the fact that you'll be able to read a word if only the first and last letters are in the right position, and the length is correct.
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I look at that and can't help but think of this guy. Surely he is the missing link between dinosaurs and birds!
(http://trilliumcg.com/mattsworld/Images/trogdor.jpg)
...somehow.
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Burninating all the peoples and their THATCH-ROOF COTTAGES!! THATCHED-ROOF COTTAGES!!
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I do believe there is actually a scientific theory about that Kosh, that the more 'radical' type of life is too fragile to environmental change, so as evolution passes (I recoil from using the word 'progresses') the gene-pool gets cleaned of the edges, so life is more resilient, but not as experimental in nature.
That's an oversimplification... some very specialized animals have survived very long periods in the fossil record, and radical change can drive evolution quite quickly if it gives the ability to exploit new niches, or old nieches in new ways. What I think you're trying to describe is the tendency for rapid and often highly unusual speciation into new niches following major extinction events. There's generally a brief delay, followed by a rapid diversification of the survivors into the niches vacated by extinct animals or plants. During this time, interspecies competition is generally fairly low, and so all sorts of relatively poorly adapted animals can survive. As time goes on though, and the vacant niches fill up, the evolutionary arms race starts again and a lot of these less well adapted animals are outcompeted.
Yet another example of very likely irreversible evolutionary path would be the cetaceans. They started as quadruped land animals and ended up with behemoths almost completely adapted to living in oceans, and for them to become capable of land life again they would need to first of all develope a mutation that makes their hind legs grow back, then reduce their size and go through some immense skeletal and morphologic changes for them to step away from water. It's very difficult to see that happening within normal evolution.
Actually, cetaceans with back legs do occur - it's not common, but the fact that they occur at all suggests it's a relatively easy mutation. But you're right that most cetaceans are unlikely to get back onto land, unless there was some sort of land based major mass extinction that left a lot of vacant niches (after all, fish did it, and they were much less well adapted to living on land). However, you'd still (potentially) have seals, turtles and lots of other better adapted animals that'd probably beat the cetaceans onto those land based niches.
Besides regarding feathers and dinosaurian/avian features, isn't it at least a very credible possibility that part or even majority of dinosaurs were feathered to begin with? Making scaly birds sounds more like kickback to reptilian ancestry rather than dinosaurian. Now, make me an ostritch that has teeth, tail and arms that it can use to grab stuff... and I'll say it is a dinosaur.
Of course, I consider all avian species to be higly specialized branch of dinosaurs and only named differently due to historical reasons...
You're basically right that birds are specialized dinosaurs, and we have a really much better idea of the evolution of feathered dinosaurs into birds thanks to fossils out of China over the last 10-20 years. We've actually got some really impressive fossil impressions of both scaly dinosaur skin and feathers - it's generally assumed that feathers were a feature of the theropods, so the majority of other dinosaurs were almost cetainly scaly - it's hard to imagine something like a brachiosaurus or an ankylosaurus needing feathers. In fact, they'd be a physiological detriment to animals that were that big due to their tendency to insulate, which'd be bad in an animal that would probably be relying on gigantothermy to maintain temperature stability.
Evolution is not directional. Defined at its simplest, evolution is simply a change in allele frequency in a population over time (if I recall correctly.) This is something a lot of people (including most of the anti-evolution blowhards) don't understand: evolution does not imply 'progress', it does not imply motion in a particular direction.
No, you're misunderstanding. The frequency of alleles in the human population as a whole is changing more rapidly than it has in the past (not merely 'mixing about'). This is the definition of evolution. Ergo, our species is evolving faster than it ever has.
That's a poor definition of evolution IMO. What you're describing is genetic drift, and while genetic drift can lead to speciation, evolution as its understood today implies natural selection. In that context, I'd say human evolution has definiutely slowed, since there's no real adaptive progress or elimination of less reproductively fit individuals, although we probably are still developing some minor disease resistance (though that too is being prevented by modern medicine keeping people alive). However, we're only talking on a very small scale in geological time... I'm not sure that, with hindsight, anyone would recognize an evolutionary pause here. In fact, given how precarious our position is on the globe (I'm talking about vs major natural disasters like meteor impacts and whatnot) we're likely to have another major catastrophe trigger massive population kill, and potentially speciation before too long. The only question is whether we can get humans off earth before that happens to maintain the species.
Certainly, we're not going to evolve anything like Mika suggested ("Weaker lower limbs? Curved back? Smaller frame? Decreased brain volume?") due to office work. That's Lamarckian. We'll only evolve along sexually selective lines, which are being badly muddied by modern medicine and whatnot, so it's extremely difficult to predict. I'd suspect we're just going to drift along until the next big catastrophe.
As for the actual topic of the thread, I very much doubt this guy is intending to replicate a T-Rex with a chicken. He's probably talking about getting the individual features of saurian anatomy out of a modern bird, like a toothy jaw, a long tail, clawed wings, scaly skin etc. Some things will be easier than others - scaly skin, dor example, is probably triggerable by turning off a very basic, very old gene that triggers feather development. By contrast, wings would be much harder to turn into limbs because of the (likely) many genes working in conceret to produce them - it'd be difficult if not impossible to find a single gene that could revert them back.
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The basic definition of evolution given in most textbooks and classes is the change in allele frequency over time in a population. That's it. Additional components like natural selection, speciation, sexual selection, genetic drift, etcetera are plugged in to flesh out the full theory of evolution, but they're not part of the core definition per se.
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Natural selection was a key part of Darwin's original theory, not something that was added on later.
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I didn't say anything about what was or wasn't present in Darwin's original theory of evolution. I just defined what the core of the theory was.
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The basic definition of evolution given in most textbooks and classes is the change in allele frequency over time in a population. That's it. Additional components like natural selection, speciation, sexual selection, genetic drift, etcetera are plugged in to flesh out the full theory of evolution, but they're not part of the core definition per se.
That's pretty close to the way I was taught it. Natural selection, etc. are the mechanisms by which the change occurs. That doesn't mean they are unimportant, simply that they aren't part of the definition.
An analogy would be the definition of a power station (A building where a fuel is converted to make electrical energy). Coal, gas, nuclear, etc are the fuel. Very important parts of the system but in no way necessary for the definition.
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Precisely!
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I have to disagree with the idea that evolution's core is simply the "change in allele frequency over time in a population". That same phrase is consistent with intelligent design, for instance. Darwinian evolution is a specific mechanism by which that frequency change occurs; change in allele frequency over time in a population is a tautology. It's the difference between a mathematical equation and a scientific theory, and evolution is an example of the latter.
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Somebody here doesn't work with population genetics.
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I have to disagree with the idea that evolution's core is simply the "change in allele frequency over time in a population". That same phrase is consistent with intelligent design, for instance. Darwinian evolution is a specific mechanism by which that frequency change occurs; change in allele frequency over time in a population is a tautology. It's the difference between a mathematical equation and a scientific theory, and evolution is an example of the latter.
Read again:
The basic definition of evolution given in most textbooks and classes is the change in allele frequency over time in a population. That's it. Additional components like natural selection, speciation, sexual selection, genetic drift, etcetera are plugged in to flesh out the full theory of evolution, but they're not part of the core definition per se.
I didn't say anything about what was or wasn't present in Darwin's original theory of evolution. I just defined what the core of the theory was.
That is the basic definition given in most textbooks and classes. Now, the entirety of evolutionary theory is far more complex, but that's what evolution is, in the same way that 'gravity' is defined very simply whereas a theory of gravity is tremendously complex.
And it's silly to say that 'the same phrase is consistent with intelligent design' because a) intelligent design is not a scientific theory, it is an ideology, and b) as in the above example, so what? A simple definition of gravity is consistent with Flat Earth 'theory', but that doesn't make the definition itself any less valid.
You yourself pointed out that Darwinian evolution is a mechanism by which evolution occurs. That's precisely correct. You defined what you were trying to say, which is in complete accordance with the statement you're attempting to contradict. Nonetheless, evolution is simply a change in allele frequency in a population; that's the definition.
And Ace is correct. In many fields you don't need to bring in all the components of evolutionary theory to see 'evolution' occuring. Simple equations and observations about allele change still demonstrate evolution.