Supplant. I expect that natural evolution will be suppressed, since unplanned alterations will simply be edited out.
You mean as opposed to tattoos and tongue piercing ? Social tastes change, and I find it implausible that over thousands of years there will never be any subculture interested in radical experiments.
For that matter, there are, I think, quite a few people right now who would change themselves pretty radically if they could. Eventually they’ll be able to do so; and once they become a subculture ( a bunch of people who prefer having four arms and a prehensile tail, or hermaphrodites, for example ) they’ll regard themselves as normal, and no doubt try to alter their children to fit.
Someone, somewhere, somewhen will do it; and I find it unlikely than every culture everywhere will always sterilize or kill the results. And if they don’t - those altered people will be there, breeding like the rest of us. And once one altered group of quasihumans exist, people will get used to the idea and more will be made.
Of course, all this assumes we won’t go the cybernetic/nanotech route and give up flesh and genetics altogether.
Good grief. Where do I start? I’m sorry Dr. PoopiePants but you have understood pretty much every fundamental point of evolutionary theory.
What you totally fail to understand is that species that adapted in an alternate fashion and more quickly still became extinct as a species because they evolved into new species. Australopithecus afarensis is extinct, yet we know many individuals evolved extremely rapidly in a variety of directions. Yet the species is still extinct. The descendants of some individuals that evolve rapidly enough and in the right direction are now the most numerous large mammal on the planet but the specie itself is extinct.
There is simply no justification or even logic in your claim that the majority of extinct species would not have become extinct had they adapted in an alternate fashion. They would still be just as extinct. The only difference is they would have left descendants.
You entirely miss the point. The point of the NZ black duck example is that a population can be well suited to its environment and not require any modification necessary for survival yet still be overwhelmed by a modification advantageous to survival. Whether that advantageous modification comes from an external species or form an internal modification is irrelevant.
Your claim that speciation can only occur if modification are necessary is proved false by that example and countless others. Speciation can and does occur if a modification arises that is simply beneficial. That is equally true whether the modification arises form species hybridisation or from an internal mutation.
I think this is the major point you fail to understand. Any advantageous mutation that arises through mutation or as a result of environmental change has just as much potential to lead to speciation as a necessary mutation.
And as I pointed out with my example of the NZ black duck, the conditions that you outlined in post #20 are not in any way barriers to speciation. If you believe they are then please present references that state that they are.
Nonsense. Please provide a reference that states that any crocodile species has not speciated for “many millions of years”. You totally fail to understand that crocodiles speciate just as fast as hominids or ducks or any other group.
Please provide a reference indicating that reflex responsiveness between non-impaired individuals of comparative age is less variable than sprinting speed between non-impaired individuals of comparative age. I think this is total nonsense made up off the top of your head to try to support your case.
So freakin’ what? All that means is that any benefit of a ‘crash survival gene’ will be higher than that of a ‘tiger survival gene’ because it also confers a direct advantage to related individuals.
You are arguing our case for us.
That’s right. And there are multiple significant factors that may increase survivability of tiger predation– I don’t consider good sprinting ability to be even one of the more significant ones. The chances of a human outrunning a tiger are nil. Personally, I would choose good luck first and sprinting away last. Tigers won’t discriminate between me and an Olympic sprinter- we are both considered to be standing still.
The fact that nobody on the history of the world has ever managed to outrun a tiger suggests that you are completely wrong. When you can provide any evidence at all to support that claim you will have an argument. Until then all you’ve got is an opinion based on an assertion in conflict with the observations. The arguments you construct from that basis can be ignored pending the provision of some actual facts.
First thing you have to do is provide some evidence that the old adage is true. From the POV of a tiger humans simply can’t run at all. We might just as well walk. Your suggestion that an extra 2km/hr makes any difference at all to a predator capable of exceeding 60km/hr seems extremely dubious. You will need to provide evidence before you can use such an assertion in this debate.
You still haven’t answered the questions posed by Lemur866 above. You need to explain how it can not ‘spur’ us to evolving better reflexes.
Look it’s quite simple. I can provide countless references that state quite clearly that any trait that results in greater survival is likely to become widespread. You need to explain why that doesn’t apply to the trait of increased reflexes and the ability to survive car accidents.
You’re the one challenging scientific consensus here. You need to provide evidence or reasoning showing why you did so.
All you have done is restate your original claim. You still haven’t explained how it is possible or provided any supporting evidence from actual scientists. Can you do either of those things.
So you are totally unable to provide evidence to support the THE point upon which your entire argument hinges.
That’s it then. You have no argument.
Humans are not wildebeest, nor are we fast or agile compared to almost all other mammals. As such this counts as evidence against your core claim that predation was the major selective pressure on modern humans.
In summary Dr. PoopiePants your entire case rests on “I believe” “I would guess”, a baseless beliefs that crocodiles speciate more slowly than hominids and an unprovable assertion that predation[played a major role in modern human evolution.
Or to summarise the summary: you have no argument, just baseless beliefs.
Of course on the off chance you can provide actual evidence for your numerous claims and beliefs I will happily reconsider, but right now you’ve got nothing but an opinion based on other opinions.
Well, I would not include Australopithecus afarensis on my list of evolutionary dead ends, nor any other species that branched off into other species – they should be considered evolutionary success stories. The point at which we decide to give an evolving, branching species a new name is an arbitrary point of nomenclature. If a species leaves descendants, they really haven’t gone extinct. The only time period that I consider A. afarensis to be dead-ended is the relatively short period of their history in between the last successful branch bifurcation and when the non-branched line finally failed to reproduce. Before the last point of bifurcation, they were successful (particularly those that branched off into A.africanus/H.rudolfensis/H.ergaster…H.sapiens)
On the other hand, numerous evolutionary dead ends have occurred since the spark of life ignited billions of years ago, do you agree? Can you also agree that there have been numerous species who have existed for long stretches of time without branching and who became extinct? I consider these to be the failures of evolution – the species who may have survived had they evolved in an alternate fashion. They are the ones who did not take the “necessary” evolutionary steps for survival.
If they left descendants they became extinct in name only.
I make no such claim, and, in fact, believe no such thing.
I agree, speciation can and does occur if a modification arises that is simply beneficial. However, this declaration should include the following caveat: “…only when conditions are favorable for speciation to occur”. Just because a species has the potential to speciate does not mean that it will do so. Again, can we agree that numerous species have gone long stretches of time without speciating? They had the potential to speciate, but they did not – why? I am simply suggesting that the evolutionary conditions of modern humans (specifically contemporary sexual selection) diminishes the likelihood of speciation occurring now, or in the future. (Your counter-argument should focus more on disaffirming those already stated conditions rather than quibbling over side issue minutia).
The question is how much potential does any particular mutation (beneficial or necessary) really have to lead to speciation under the evolutionary constraints (genetic drift, flow, sexual selection) of contemporary humans?
Better still, take a stand and tell us how and to what degree you feel humans may evolve. You may hesitate, claiming that future environments are an unknown, but use the OP ground rule assumptions as a starting point and give some educated guesses. This is, after all, nothing more than a thought experiment – it will take a million years before we can take away points for wrong answers.
You seem intent on making a bigger deal about crocodiles than I ever intended. My main focus in this thread is human biological evolution. My thesis is that humans will change minimally in a million years. I assumed that some people would find a million years too long a period to expect any species to exist without changing very much or speciating. For those people, I wanted to remind them that some species have gone very long periods while changing very little (so entertaining the thought of human evolutionary stasis would not seem so preposterous by comparison). I could have given other examples, but I used crocodiles for no other reason than I was looking at an alligator out my back window at the time, and they are related to crocs. It was a simple point, minimally germane to the prime topic and hardly worth getting ones panties in a bunch over. Do you not believe some species have gone millions of years without evolving very much? Is your objection specifically with crocodiles? Would you feel better if I used another species as an example? How about the coelacanth or the cockroach, do you feel better about them?
Obviously, there are multiple species of crocodiles (some alive, some extinct), so speciation took place at some point(s) in their history. The consensus seems to be that they speciated early – splitting into the modern lines over 80 million years ago, and they have changed little since that time. Is it safe to assume hominids and ducks have changed more, and speciated more recently, than crocodiles?
Unfortunately, I found valid research on the correlation between human speed and avoidance of grizzly bear disembowelment to be quite sparse. (Apparently they have a difficult time recruiting human subjects for the studies). So, in the absence of proof, sometimes you must simply employ educated guesses. My educated guess on this matter is as follows:
Assumption: Predation played a very minor role in our evolution (not the major role that you claim I asserted). It played a much more important role in the evolution of many other animals of prey, however.
I wholeheartedly agree with Lemur866’s claim that early humans were rarely alone, that they would attempt to avoid predators first and foremost and that when confronted with a predator, their first response would be attempting to scare them away. (And, of course humans have zero% chance of outdistancing any predator). I’m sure that those tactics were successful in keeping many early humans out of more than a few GI tracks. On, the other hand, those first line defense tactics were not always successful. Early humans were killed by predators and they are the ones that I’m concerned with (and this is where I believe our opinions differ).
Who gets killed in a group of humans when defensive measures fail? It could be random chance, but I don’t think that was the case very often.
Scene: Lemur866, Blake, Ekers and Myself in grizzly bear territory.
While foraging for nuts, our quartet gets too close to a huge, foul tempered grizzly bear and he begins to charge. As the bear gallops forth and rears up on his back feet, Blake and Lemur866 begin poking the 9’tall Ursus arctos horribilis with their little sticks. After a moment the blood spattered predator hops over the bodies and turns toward Ekers and me. Normally, in pickles like this, Ekers and I would try to protect one another, but as the bear’s slobber begins to spray us in the face, our “fight” response turns to “flight”. I know I can’t outrun the bear, but I think I can outrun Ekers, and I do. The bear has a choice, he can kill me in 8 steps, or he can kill Ekers in 4. Am I worth the extra 4 steps? I end up in a tree watching the bear use Eker’s clavicle as a toothpick. Later, I go home and impregnate my wife. I think similar situations played out in our past, but obviously not often enough for us to have evolved wildebeest-class speed.
Again, this human v. predator topic is just another side-issue with very little relevance to future human evolution. I suggest staying closer to the main topic.
But if your sole point is that in 1 million years time our descendants will be as different from us as we are from A. afraensis then you are perfectly correct. Nobody here will argue that pint with you.
We all appear to be in total agreement.
Ahem “As opposed to other species (and ours, in the past), we are no longer at the mercy of the environment to quite the same degree - at least not to a degree necessitating more than minimal biological adaptation.”
You said outright that moderate or maximal biological adaptation (ie speciation) can only occur if the environment makes such changes necessary. Don’t try to weasel out of our claim now please.
Good, and since we can prove that faster reflexes are beneficial we can discount your entire nonsenicla argument that such processes can not lead to speciation.
And we are all pointing out that there is no reason whatsoever to believe this.
We have been pointing out that you fundamentally misunderstand evolutionary biology. Nothing whatsover to do with minutiae. You quite clearly don’t grasp the very basics.
Good, then find one. Please name one species that has gone a million years without speciating.
That’s nice. Provide a reference that says that. None of the references you provided support such a claim. Not one of them names species of crocodile that existed for over 1 million years. Your claim to the contrary simply shows once again that misunderstand completely the fundamentals of evolutionary biology.
Of course if your sole point is that in 1 million years time our descendants could very probably be as different from us as Crocidilus niloticus is from Eusuchia then everyone here agrees with you.
No, of course it bloody isn’t. That was my whole point. That’s why I asked for a reference for your ridiculous claim to that effect.
You have fundamentally ,misunderstood evolutionary biology. Crocodilians as a clade have along history. Antrhropoids as a clade have along history. Aves as a clade have a long history. Individual groups of crocodilians speciate neither faster nor slower than birds or hominids.
Yes, but we’ve already pointed out at length why that ‘educated’ guess is incorrect. Thats’ why we asked for independent evidence to confirm what you stated so boldly was fact. That you can’t support it with any evidence proves that it is not based on education either.
The main topic was resolved in the first 3 posts. Since then we have simply been pointing out why your argument to the contrary makes no sense and is based on ignorance of or best and totally misunderstanding the facts.
The main point is that we’ve asked for evidence for the numerous ‘facts’ that you have based your position on and you have been unable to find any. I’m sure your position would make a neat sci-fi story but this is GD, not Café Society, and it;’s lousy science and lousier reasoning.
Hardly. Unless by “all” you mean your id, ego and superego.
You refer to yourself in the plural “all” quite a bit. Are you referring to the general scientific community or the other posters to this thread? Indeed, most posters to this thread agree that humans will evolve in 1-million years, but most are not speculating as to the direction or degree of change we are likely to experience, citing the quite valid reason of not knowing what conditions we will face in the future. You, on the other hand seem to be one of the few to imply that humans will definitely biologically change a great deal and most assuredly speciate (posts bringing genetic engineering into the formula don’t count). You posture your position as being in alliance with the general scientific community and all the other posters who have not taken the extreme position that you have. I take an opposing position (i.e. humans will evolve minimally in 1-million years) and you vilify me as being ignorant of science. You nit-pick, fabricate and polarize (see below). Normally, I would be entertained by such antics if you added something productive to the thread (well, there was that duck blurb :rolleyes: ), but if I wanted to engage in this type of debate, I would just argue with my wife. (Hmmm, Blake = my wife…naw, it couldn’t be)
I believe that I made it clear that I don’t profess to be an expert in this field; so frankly, I would be quite surprised if I didn’t make a few mistakes. When those mistakes are pointed out in a productive and civilized manner, I welcome the enlightenment (like when Lemur866 pointed out my erroneous belief about human heterogeneity…although, I would like to discuss that further). Lemur866 et al contributed some well thought out, productive posts, but as I understand them, they have not completely closed the door on the concept of minimal human evolution. I would like to further discuss the likely effects of natural selection (particularly sexual selection)on the evolution of contemporary humans in future posts - once we get past this hijack to the land of minutia and irrelevancy.
So, you’re saying that “we are no longer at the mercy of the environment to quite the same degree - at least not to a degree necessitating more than minimal biological adaptation.”=“moderate or maximal biological adaptation (i.e. speciation) can only occur if the environment makes such changes necessary”? I beg to differ.
Don’t try to weasel in words like “only” in order to polarize my statements, please.
If you’re going to fabricate/alter other peoples statements, why not cut out the middle man – start up a new SD screen-name account and debate yourself? (but please, give your new persona a spell-checker)
While your at it, please provide evidence to support this [del]opinion[/del] scientific fact of yours:
But will it lead to speciation? The question becomes, what percentage of the population is killed by car crash because of poor reflexes and is that percentage high enough create appreciable biological change?
Let me oversimplify the situation:
U.S. population: ~300,000,000
Annual car crash deaths: ~42,000
Adjust to represent 1 generation: 42,000 x 30yrs = 1,260,000
% killed as a result of slow reflexes: Unknown. Can we agree on a very generous 20%? If yes:
1 generation car crash deaths due to slow reflexes: 252,000
0.084% of 1 generation is killed by car crash due to slow reflexes.
Is a 0.084% selection bias enough to lead to speciation, or at least
Lemur866 suggests that a 1% selection bias makes a huge difference over many generations, so what sort of change can we expect a 0.084% bias create – small change or no change (genetic drift drives the fast reflex allele to extinction)?
If you answer small change, or no change, I agree. If this assumption is correct, then I’d like to re-visit my original hypothesis:
I believe that contemporary human sexual selection may create similarly low percentage selection biases in most other alleles, the result being minimal biological evolution for humans. Debating that particular point would be productive.
You claim humans will speciate in 1-million years or less; I hypothesize that they won’t.
According to you, I’m engaging in “lousy science and lousier reasoning.” Well, here is another guy who engages in “lousy science and lousier reasoning.” http://www.open2.net/truthwillout/evolution/article/evolution_hurst.htm
Apparently, the professor believes that speciation is unlikely, but if it occurs it will take well over a million years. Why don’t you nit-pick with him?
I’ll be off this thread for a couple of days to attend a seminar*.
Another fellow who assumes the nonexistence of genetic engineering. Suppose the people in the US genetically engineer themselves one way ( say an improvement to the immune system and so on ), and the people of France do so differently, and the Chinese choose a third. It won’t take massive changes before the various groups can no longer interbreed without technological aid, which either makes them different species or requires a redefinition of the term.
IMHO, we’ll see new human-derived species ( or their functional equivalent ) within a hundred years or less, not millions of years. People may redefine the word “species” because of this, which is why I added “functional equivalent”.
Der Trihs: I agree that genetic engineering (GE) will bring about greater change in the future human genome than natural selection (NS) and GE may even act as an anticatalyst to NS, however, we disagree as to the magnitude of change that GE is likely to have on our species.
The following link is to a site that seems to be in alignment with Der Trihs’ position (correct me if I’m wrong): http://www.human-evolution.org/genetic.php . Though obviously a pop-science forum, I agree to some degree with the role that this site predicts GE will have in the realm of future human evolution with regard to disease elimination, longevity, capacity and even fashion, but I don’t accept the predictions made with respect to GE’s role in human adaptability/pantropy.
The following are a couple of points that, IMO, dampen the effect of GE on human speciation:
Bioethics: I think most people today agree that limited human biological enhancement is acceptable, but transmogrification and speciation is not. I propose that there is an innate repugnancy to the latter, and it will always be viewed as such. And, as such, wide-scale human species alterations will be restricted. The same restrictions will probably not apply to how we engineer non-human species and may not apply to how future non-earthbound humans are engineered (pantropy may be necessary for their survival).
Genetic Drift and Gene Flow: Isolated pockets of humans are rare and becoming rarer as time goes on. Your example of the people of France and China being genetically engineered so uniquely as to lead to speciation is simply not a likely scenario. It’s really a numbers game in the end: for mutations to fixate in a large, unobstructed population, a significant number of those particular mutations must be present. Speciation may be easy to accomplish in small or isolated populations, but that is not what we have on earth today or likely to have in the future. Rogue scientists may genetically engineer ghastly human monstrosities, but their numbers will never be sufficient to affect the human population at large. Again, future human extra-terrestrial colonizers present a different situation: they will be small, isolated populations susceptible to the effects of even minor mutations. Given enough time, they may very well evolve quite differently from their earth-bound brethren.
Most people, today. It’s not a universal opinion, and I simply see no reason to believe no future culture or subculture will never, ever decide to make major alterations. And once those new people exist, they will continue to do so and breed and evolve on their own; unless killed, of course.
Why do you think people will care if their children have a few extra internal organs, if those children are faster or stronger or longer lived ?
Why not ? Unless some sort of Genetic Empire is set up to impose genetic standardization all all nations for all time, different nations will choose to make different alterations. Even small alterations will cause speciation if they cause genetic incompatibilites. I’d be very surprised if that doesn’t happen.
Which is something genetic engineering can easily accomplish.
Physically isolated, no, but diverging genetic engineering plans between cultures can ( and I think will ) produce genetically seperate/isolated groups.
And how do you know everyone in the future will consider major alterations “monstrosities” ? And how do you know that the “monstrosities” won’t genetically outcompete us, like Cro-Magnon did Neanderthals ? With genetic engineering available, they wouldn’t even need to kill anyone, just convince mainstream humanity over the generations that they are a better design.
