Evolution

RudyGarmisch

RudyGarmisch

Active member
Staff member
Ok, I've been reading this book by Richard Dawkins called The Ancestors Tale, and its one of the most thought provoking books I've ever read. Great book, even for non-biologists, I'd recommend everyone read a few chapters. He traces humanity back through generations and talks about species that join up as he takes us back through our lineage. Anyways, I digress.

One really cool idea I just came across: Gulls in the UK. There are two separate gull species that nest there, one with black wings, the other mostly white. They dont interbreed, and scientists have given them two different species names. One species proliferates westward, the other eastward. However, if you start sampling the gulls in either direction, the further you get away from the islands, the more grey they become... until around halfway across the globe, the two separate species both look very very similar, and in fact interbreed. Its like a spectrum, where each individual is able to interbreed in say, a westward direction... and it wraps around so far that by the time you reach the end of the spectrum, the individuals are separate species. Freaking crazy.

This can be applied to a broader range however. We really dont have separate species... ever. Its just that the 'links' between species have died out. For example, if some of the ancestoral apes that walked africa still existed, its reasonable to believe that members of our species could breed with them, and those could breed with others... until there was a chain of interbreeding that directly linked chimps to us. Humans and chimps could never interbreed, but through all the intermediates, we would cease to be separate species....

This is back to another idea as well. In the fossil record, we never really have distinct species. All we see are snapshots of an ever changing morphology. In fact, its good that we have gaps in our fossil record... if we didnt, and had the bones of every single species that ever lived, we would never see distinct species, just transitional forms. A cool analogy would be to think of evolution like a tea kettle. Theres never a point in the water where it goes from 'cold' to 'hot', yet it still boils. People need to stop thinking of evolution or speciation on the whole as specific and distinct.

Anyways, cool rant. Richard Dawkins is a great author, really thought provoking stuff. Check it out!
 
nice post Rowen, I've never heard of that book. I read The Selfish Gene by Dawkins, it was super interesting. It was all about evolution and how its centered around the survival of the genes, not the individual, species, or any other group. He also tied in game theory in his explanations of animal behavior. All of his explanations are really thorough and detailed. I want to read his book The God Delusion, that also sounds really interesting. I had a crazy excerpt from it that explained and tied together altruistic behavior and evolutionary misfirings, but I think I deleted it. I still sort of remember the part about evolutionary misfirings though. Consider sex. Its purpose is reproduction, and since this is a good thing that aids the survival of our genes, its programmed to be extremely pleasurable. But what about protected sex? It doesn't affect the survival of our genes at all, but since sex is programmed to be pleasurable, people do it alot. Thats an evolutionary misfiring, where one trait designed to help the survival of an animal's genes also aids another unintended behavior.
 
I actually had a guy come to my house the other day. Ring the door bell, and ask if he could come in and talk to me for a little while. So I said fuck no what are you selling and he told me that he was selling nothing but opening my mind.

So I am not really doing anything so I let him go on about his speel about intelligent design and all this bull shit about how the dinosaurs lived with humans and shit.

So I waited till he was done and then unloaded just about every shred of scientific proven evidence I could dig out of my brain thus crushing all of his points.

So I thought at least he would think about it for a bit but he come right back at me with "The bible says..." So I was like the bible is a book. And closed the door.

I hate that shit, has anyone seen that museum that opened in Kansas or some shit that has an exhibit of humans and dinosaurs hanging out. It is madness. If these people knew anything about evolution or carbon dating or anything. God delusion is right its the most powerful drug out there.
 
to some degree you are right, but i would have to disagre with you and most of it.

a species is a population of specimens that inhabit the same region and mate with each other.

I will use your example with the gulls. What happens to them when they get farther away from each other is called divergency, wich is a procces of separation of their distinguishing features. in other words the third gulls you are talking about are a third species and have a similar, but diffrent evolutinary path than the other two.

About the fossils, how can they not be distinct species, acording to you theory the t-rex and the terodactil are one species, wich by every criteria is wrong. Morphologicalty they are diffrent, physiologicaly they are diffrent and so on. all this proves your third thoery wrong. they may both come from the same single celled liveing being, but through evolution they have become diffrent species. and Just because there isn't (to my knowledge) a great diffrence between the last neanderthal and the first homo sapien, dosen't mean that they are the same species. we don't have sientific proof that they wern't Morphologicalty diffrent. maybe what we now think to be fossils of two diffrent species are really the bones of mother and child.

sorry if my terminology isn't that great. i have biology as a profiled class, but not in english.
 
Ah, ok, maybe think about the gulls like so.

Each gull has a certain 'ring' or an area and nearby population in which it can mate. If it goes outside the ring, it cannot mate with the other ones, as the difference are to great. However, the rings of many of these gulls overlap, and the small changes continue around the globe, and go until you have two distinct species that cannot breed with each other (which is a main feature that delineates a species from another, ability to produce viable offspring). Through all the intermediates, which do breed with each other, they are essentially linked... its just that the two ends of the spectrum are so morphologically different they have become separate species.

AS for the dinosaur thing, I was probably unclear. I'm saying a few things. First, there are no distinct species. All of the fossils we have found are transitional creatures. We just find individual species at certain points in time which look different from other fossils, so we call those species. While you do have relatively sudden changes possible with evolution, theres no reason to think that all of the "t-rex" skeletons we will find will be absolutely similar. They will undoubtably have small morphological changes depending on their age and location. Basically, what I'm trying to encompass is that there was never a point where a dinosaur stopped being a primitive carnivore and suddenly became a T-rex. Its just that we have that individual slide out of a sorta greyscale of that lineages evolutionary history. Thus, its a good thing we have gaps, and they are to be expected, unlike many creationists suppose.

As for the Neandertal and Homo Sapien, the jury is still out on whether they could breed viable offspring or not. However, the point I'm trying to make is that the same thing I was saying about gulls can apply to humans and chimps. If all of the intermediate forms of ancestral humans that walked the plains of africa survived, you could feasibly still have a spectrum from humans to chimps, just like the gulls. If you have enough transitional species, they could still breed with those closely related to them, and you could form an unbroken chain linking two separate 'species' to each other.

Maybe another approach to this idea is needed. Say I go and pick up a pigeon. I take it in my time machine and go back 1000 years, where I find one of its great great grandparents with my pigeon-locater and snag him. Now, the two pigeons would be close enough genetically to breed and produce viable offspring. I go back another 1000 years and pick up another great grandparent of the original pigeon. Though this one cannot produce a viable offspring with that original pigeon, it can breed with the ancestor from 1000 years earlier. If I keep going back, which will take a while, probably more time than I have in my lifespan, I could set up a chain of ancestors. Each ancestor could breed and make viable offspring with its 1000 year old ancestor and its 1000 year old descendant, but no other. Even 5 forms away, the lineage would start to look very very different. Eventually, I'd be picking up reptilian ancestors, which are clearly not the same species, even family of life form. but they're still 'linked' together through their ability to interbreed with those around them.

My point is that evolution doesnt produce distinct species. It never does. Its always a spectrum of different life forms, both across the present array of life (we're just missing all the intermediates) and into the past. Gaps are to be expected, indeed, they even support the idea of evolution.
 
i feel like dying. i wasted a good 10min writing an answer, and when i pressed reply i got

The following errors were found in your submission:

(dot) Your post's body can not be empty!

 fuck this.

simply put in as little detail.

Species in the same genus can mate. your theory can be aplied as long as the species you choose to mate stay in the same genus.

example. diffrent types of pigions can mate because they are in the same genus. a pigion and an ostrich can't, because they aren't in the same genus, even though they are in the same family.

i'm gotta take a shit,

fuck this. my original raply was so good and detailed.

:(

another 15 mins wasted on NS, atleast i rememberd some of my biology.
 
Yeah, but the point I'm making is that 'species' can break this if transitional forms exist that can interbreed. If all of the transitional forms between an ostrich and a pigeon did not die out and continued to somehow survive, you could theoretically trace from pigeon to ostrich between these transitional 'greyscale' forms. Species are only species because these intermediary forms have died out.

And that sucks about NS being a bitch, its done that to me many a time.
 


A big point of evolution is that some species will survive while some will die out due to genetic reasons, thus survival of the fittest holds true. So I dont get the point of this thread.
 
Oh, I completely agree. I guess the point of this thread is that we need to stop thinking of species as species, and instead as just small snippets of a wider spectrum, much of which has died out.
 
evolutionpq6.png


Here. In this example I just whipped up, think of every circle to be a individual bird lets say. And the color like their wing color. Now, say the red one lives alongside the green one, at opposite ends. However, the red one can breed with the circle next to it viable. That individual can breed with the one next to it, and so on. At one point, a red one will be morphologically distant enough from the pure red one and similar enough to a dark red one that they'll be able to viably breed. If this continues out, you can see how the green and red ones would technicaly be both different and same species - they cannot breed, but through thier indistinguishable intermediate forms, they are the same. Thus, species is more of a misnomer than anything, and its incorrect to believe it to this extent.

Also note the black lines I made, which represent lineages of the individuals. In the past, there was interbreeding as well between some lines. Its fair to assume this too with human populations: there probably never was "one" ancestral mother that diverged from Austropithecaus, or any other ape, but rather a large interbreeding group that slowly went its own way from that lineage. All of those lineage lines you see in family trees arent just one lineage; its many of thousands of interbreeding individuals.
 
thats exactly what hte evolution tree is and it has always been viewed that way since Darwin.

The whole spectrume is life itself, Then you just divid it up into catagories (animals, plants and mushroom), then subcatagories, and keep dividing until you get to the main unit of microevolution - the individual species.
 
Oh, I agree with that. But what I found fascinating to think about is that if species did not delineate into separate forms and if all the transitional species remained alive, we wouldnt have a tree with lots of pointed ends signifying species... we'd have a veritable spectrum of organisms that would all be transitional forms between each other. In that respect, you could trace from human to bacteria through these transitional species that would not be separate species if viewed side by side...

Again, kinda hearkening back to the whole water going from hot to cold. If you measure just between a few molecules near the top of the column or bottom, you wont see much change and you could call them nearly the same temperature. But take a sample from the water near the hot iron and the water near the top thats still cold and you'll see a radical difference. Its in this same respect we see individual species.
 
but the far green cannot breed with the far red right?, doesn't this just show how species with a geological divide come to be, and that there is never any exact moment of change between ancestors to their branching species?

ie evolution takes time, give it time and the green and red will eventually be truly different species?
 
1st. the red one and the green one are differnt species in the same genus, therefor they can breed. the red one is created by divergency. in this case divergency would be migration of part of the population of the species. after migrating they adapt to their new inviorment and change if the region is diffrent. those that adapt- survie, those that don't-die, thus creating a new species of birds. and from there the black lines are incorrect becasue the red bird is a direct decendant of the green bird.

evolution occures when there is a change to the enviorment. the natural pick eliminates all bad adaptaions and saves all the usefull adaptaions.

mankind originated in africa. After millions of years of evolution (or adapting to the constant changes in the enviorment) the monkey evolved into the homo erektus (i think thats how it would be spelled in english, Rowen, correct my spelling if its wrong), wich then migrated into asia ond europe. after migrating it came into contact with new climates, thus begining the creation of new races.

the diffrent footsteps in the human evolution never really mated, because those who didn't adapt to their changing surroundings died off (survival of the fittest) and couldn't mate, while the next step in the evolutionary cain were adapted and continued to make babies.

After migrating the diffrent human populations would become isolated from ona another. so they could only breed within their own population.
 
Yeah, far green cannot breed with far red. Technically, this means they are different species... but the transitional forms between each of them render them the same. Its not just geological change, but yes, theres never an exact moment of change, and thus, never exact species.
 
ok, but take the example of melting ice. first all of the ice has to melt into water before it starts warming up. you can't take a bucket of ice, melt half the ice and have the rest of the water become 10 degrees C. first all of the ice must melt, for the water to warm up (or the original species must die, for the new species to be able to mate to the fullest.) things like that occur due to changes in the enviorment.
 
Well, for one, Red and green are like the gulls I mentioned earlier, where they are different species. Time would be on the y axis roughly, but my art sucks, so dont read too much into it.

image001.jpg


This is kinda a cool graphic. I think I can use this to best illustrate my point. Though all these transitional forms between the 'lines' of speciation have died out, you could take the previously mentioned seagull example and apply it here. If the forms never died out via competitive exclusion (lets say a half chimp half human didnt have any selective advantage or disadvantage), then the chart would get filled in... sorta greyed in. Instead of direct lines you would just have a sea or dots, each an individual ancestor. Pick one out between chimps and humans and it would look like a hybrid. It would be able to breed with the dots immediately around it in both the x and y directions, but no other. These 'seas' exist in some populations (like the gulls as mentioned, where the same interbreeding specie can get so spread out that its ends no longer can breed), while in others, like in humans and chimps, the intermediary forms do not exist because way back when, they died out, probably for an assortment of reasons.
 
i'm going to bed, tour theory is only theoreticly possible only if the diffrent species could mate. and all that would happen is a fast forword/rewind effect. and new species in a given genus would be created.

good night rowen, its almost 2 in the mornig here and i have to get up at 6:30.
 
Night dude... I'm not sure I'm getting what you're saying, but by all means, feel free to elaborate tomorrow!
 
This thread is way to core for me. It's summer vacation, I don't have time for this educational bullshit!
 
This topic is right up my alley. I'm actually double majoring in Biology and Physical Anthropology.

I'm actually kind of impartial on Dawkins. His book "The Selfish Gene", is actually a naturalistic fallacy. He's drawing the conclusion that organisms are simply nothing more than vehicles. Vehicles that transport, and do the bidding of genes. While today most modern evolutionary biologists would disagree with him. Because we know that behaviors (especially in humans) are not just simply gene regulated.

For those of you that are unfamiliar with what a naturalistic fallacy is, he's a little read.

http://en.wikipedia.org/wiki/Naturalistic_fallacy

But if that is too confusing... it basically means that Dawkins was basing conclusions on an idea that nature is "good" and "more desirable". Social Darwinism was actually a naturalistic fallacy as well.

But I do agree with Dawkins on the speciation issue. Humans did not simply evolve from other primates overnight. In my anthropology experience, I've seen different skeletons that seem to be quite in between many of the cut and dry human ancestral species we have classified. Technically there really could be an infinite number of species.

I'm tired. I'm done with this right now. Maybe I'll continue tomorrow if i get bored at work.
 
ok, lets say a species evolves from A to E stage in evolution (B to D beig the diffrent steps in evolution)

A -> B -> C-> D -> E

what your original theory is that the diffrence between A and E are to great for them to mate, but D and E could. that would make a new species G for instance.

lets look at this theory mathimaticly

A+B= J

B+C= L

then

J+L would = a third brand new species F for instance.

but the thing is, that most species have a diffrent number of chromosomes and species with diffrent chromosomes can't give a prolific offspring. they can have sex, but being animals they would sense their diffrences and choose not to. And even if they did have an offspring it would be like a mule. Horse and donkey hgive birth, but their offspring can't and die out.

Evolution is all about adaptation. for B to come into existance, their needs to be some sort of change in the enviorment that A inhabits. And those adaptations would come during the time the the B baby is in the whomb, till it reaches maturety. Once it can mate, it will instinctivly choose to mate with another "evolved" being, because it will sense the diffrence.

simply put, even if every species existed right now (wich is impossible for many reasons) they still wouldn't mate. Would you mate with a hairy neanderthal? i sure as hell wouldn't.

oh, i almost forgot. specimens A to E are in the same family, but diffrent genuses (genus is a subcatagory for family).
 
No, thats not my original point, sorry I wasnt clear. In your example, and we're talking species, not genus, A and E would not be able to breed, but the transitional forms just next to each other, say B and C, could, thereby designating them the same species, as per definition of species. I'm not talking about the offspring evolving into a new species... the offspring merely are there to prove that the two individuals can breed, and thus be classified as a single species.

Back to the gull example. Two different birds in the UK that nest in the same area. Morphologically, they are very close, same family, genus, but they do not produce viable offspring when they reproduce, so by default, they are not the same species.

Yet, they are. The white and black gulls have a short range, and only breed within a few hundred miles. White ones thus breed with other white ones in the westward direction (and accordingly black gulls extend east, with the UK as being the white and blacks only point of confluence). The gull populations ranges can be thought of as 'rings'. Whites with rings that overlap can breed, as do blacks. However, as I mentioned, an interesting phenomenon is seen to occur. As you sample the white gulls as you go westward, their color begins to shift from white to grey. All the gulls you would pick up along your way could all breed with the ones immediately before and after it (eg, gulls within its 100 mile ring). as you continue westward, the color gets darker and darker... until you end up in the UK again, with completely black gulls. Completely black gulls that cannot breed with what is technically its own species, eg, the white ones. Thus, by this chain of linkage, it becomes evident that species really do not exist as such discrete and bounded 'families' as we always think. Its true that in many cases, this effect of a spectrum does not occur... but it does with our ancestors, and the non-present transitional organisms that would exist between species if natural selection had equally favored all types of life (which in effect would negate evolution, and thus is an effect we do not see, except in extremely rare cases like the gulls, where color does not play a significant role and the geographical distribution is large and unbroken enough for this to occur.

Dawkins is an expert on explaining this stuff, I'm really rubbish. All in all, its a fascinating aspect of evolution, and in my opinion, a revolutionary and sensical way of understanding species and ancestry.
 
i think we need to specify the definition of species.

Species (taken from dictionary.com)

Biology. the major subdivision of a genus or subgenus, regarded as the basic category of biological classification, composed of related individuals that resemble one another, are able to breed among themselves, but are not able to breed with members of another species.

Seeing as the gull are metioned aren't morphologicly the same, therefor they are not the same species. another criteria for species is their geographical location. the gulls don't inhabit the same region, therefor they are not the same species. Then their is morphological mutability (i'm pretty sure thats how the term would be in english), wich allows the specimens the change their phenotype, but those changes don't change their genotype, in other words it dosen't affect their offspring.

an example for this is the himalayan rabit. it is normally black at normal tempreture, but if you put a block of ice on its back, the spot where the ice was would turn white. So maybe the gulls changing color is due to their morphological mutability.

bottom line is that there is a very slim diffrence between the diffrent species, but they are diffrent for one reason or another.

And the thoery of infinate species would suggest that me and my mother are diffrent species, wich is not the case. a new species evolves from another once the boarder criteria is crossed.

thats my veiw of this subject, today i almost kicked my biology teacher in the head for being a bitch and giving me an 5 instead of and 6 for the year, fucking bitch. (grades here in bulgaria are from 2 to 6 and no grades inbetween).

 
Yeah, but thats what I'm saying. I agree with your def of species, but the gull color is not just a induced geographical trait. They actually are separate species in the UK; they cannot interbreed, and have enough genetic difference for most biologists to sort them into two sub species. However, as you wrap around the world, that genetic difference begins to lessen, and there is never a point where the gulls 'cease' to be one species.
 
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