Why are our supposed ancestors extinct?

[Improvision]

Note title

[insane_alien]

because they died.

[Improvision]

because they died.

How did they die?

[insane_alien]

various reasons i'd imagine. much like humans today dies of various reasons.

 

predators, old-age, disease etc etc.

[Mokele]

Luck, basically. Remember, 99.99% of all things that ever lived have died, and true phylogenetic trees of life are littered with dead branches.

 

Hominins (defined as organisms closer to humans than chimps, encompasing what most would call "pre-humans") are a relatively small lineage of a relatively small family in a small order of mammals that only really inhabited a relatively limited area (aside from a few expansions). We're also fairly large organisms, which means we need more food and area to survive, and warm-blooded, which means we need still more food and area, meaning a given area of land can only support a few of us. We're also highly versatile, not prone to specialization, making competition likely. Taken together, you'd expect any lineage with this combination of characters to show a relatively limited diversity of extant members, including being a single-member subfamily.

 

It's also worth noting that the times there were more than one hominin are when hominins violated some of the above, chiefly by migrating out of Africa to new regions.

[Improvision]

various reasons i'd imagine. much like humans today dies of various reasons.

 

predators, old-age, disease etc etc.

That doesn't explain why a species would stop reproducing more of its own.

 

There is no evidence explaining why cro-magnuns or neanderthals are gone. Nothing to explain why the dinosaurs are gone.

[insane_alien]

That doesn't explain why a species would stop reproducing more of its own.

 

they didn't, the death rate was greater than the birth rate untill there weren't enough left to give birth to more.

 

There is no evidence explaining why cro-magnuns or neanderthals are gone. Nothing to explain why the dinosaurs are gone.

 

there's plenty, we killed neanderthals and a big meteorite wiped out the food that supported the dinosaurs.

[Improvision]

Luck, basically. Remember, 99.99% of all things that ever lived have died, and true phylogenetic trees of life are littered with dead branches.

 

Hominins (defined as organisms closer to humans than chimps, encompasing what most would call "pre-humans") are a relatively small lineage of a relatively small family in a small order of mammals that only really inhabited a relatively limited area (aside from a few expansions). We're also fairly large organisms, which means we need more food and area to survive, and warm-blooded, which means we need still more food and area, meaning a given area of land can only support a few of us. We're also highly versatile, not prone to specialization, making competition likely. Taken together, you'd expect any lineage with this combination of characters to show a relatively limited diversity of extant members, including being a single-member subfamily.

 

It's also worth noting that the times there were more than one hominin are when hominins violated some of the above, chiefly by migrating out of Africa to new regions.

That doesn't explain why they died out.

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they didn't, the death rate was greater than the birth rate untill there weren't enough left to give birth to more.

 

 

 

there's plenty, we killed neanderthals and a big meteorite wiped out the food that supported the dinosaurs.

How do you know what the death rate was?

 

How do you know we killed the neanderthals?

 

They haven't found evidence of a meteorite being responsible for the mass extinction of dinosaurs.

[insane_alien]

How do you know what the death rate was?

 

we know it was greater than birth rate because we find less skeletons later on in their history indicating a declining population

 

How do you know we killed the neanderthals?

 

we know what weapons were used to kill them from the marks on their bones. usually more advanced weaponry than the neanderthals had.

 

They haven't found evidence of a meteorite being responsible for the mass extinction of dinosaurs.

 

a 100 mile diameter crater isn't evidence?

[Phi for All]

That doesn't explain why a species would stop reproducing more of its own.

Predators who are more successful in the same niche would.

 

There is no evidence explaining why cro-magnuns or neanderthals are gone. Nothing to explain why the dinosaurs are gone.

What kind of evidence are you looking for? If we didn't have historical documentation, what kind of evidence would be left behind to tell what killed the Dodo?

[Improvision]

we know it was greater than birth rate because we find less skeletons later on in their history indicating a declining population

 

 

 

we know what weapons were used to kill them from the marks on their bones. usually more advanced weaponry than the neanderthals had.

 

 

 

a 100 mile diameter crater isn't evidence?

Fewer skeletons is not evidence of more deaths, it is simply showing fewer of that species. Nothing is showing how the decline was occurring.

 

ALL of them show evidence that they were "killed"?

 

A crater is evidence of an impact. It does not show what has happened during and after the impact.

Edited July 25, 2009 by Improvision

[insane_alien]

if you can tell me how there can be fewer of a species later on without the death rate being higher than the birth rate, please let me know. i'd be very interested to know how this can happen.

[Improvision]

Predators who are more successful in the same niche would.

 

What kind of evidence are you looking for? If we didn't have historical documentation, what kind of evidence would be left behind to tell what killed the Dodo?

Nope...

 

Evidence that can show what happened.

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if you can tell me how there can be fewer of a species later on without the death rate being higher than the birth rate, please let me know. i'd be very interested to know how this can happen.

It would make sense that a higher number of dying members of a species than the number of births would lead to the species becoming extinct. There has to be some reason as to why they are dying and are not reproducing.I have not seen the reasonable cause of this effect. Edited July 25, 2009 by Improvision
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[Sisyphus]

Maybe you could give an example of the kind of thing you're looking for? Are you asking why a species becomes extinct? That depends on the species. Less food, more predators, conditions changing faster than the species can evolve - all result in more deaths and fewer surviving offspring, so the population shrinks. If it shrinks too much, it goes extinct. The dinosaurs, for example, probably mostly died off because a large meteor impact radically altered the global climate in a short period of time, and most couldn't survive the new conditions.

 

Of course, the more literal answer to the question in the title, why did our ancestors go extinct, is that they didn't. They evolved into us.

[Improvision]

Maybe you could give an example of the kind of thing you're looking for? Are you asking why a species becomes extinct? That depends on the species. Less food, more predators, conditions changing faster than the species can evolve - all result in more deaths and fewer surviving offspring, so the population shrinks. If it shrinks too much, it goes extinct. The dinosaurs, for example, probably mostly died off because a large meteor impact radically altered the global climate in a short period of time, and most couldn't survive the new conditions.

 

Of course, the more literal answer to the question in the title, why did our ancestors go extinct, is that they didn't. They evolved into us.

We don't know anything about the conditions they were living in.

 

I assume you mean one species is transit another species.

 

I saw a tv program a while ago where foxes were being bred in captivity. Outside of their natural habitat, each successive generation of pups were less and less aggressive towards people and they started to have less of a camouflage pattern in their fur. It seemed as if somehow there was an inner consciousness in the animals that had become aware of the environment they were in and influenced the DNA and change in the physical and mental traits in their offspring.

 

I see myself being aware of my thoughts and being able to control them. I choose what I want to think about and I choose hoow I am going to act.

 

I was having sex a few years ago with women I didn't even care for. It felt dirty. I decided that I want to stop and find a real relationship. I have sexual urges, but they don't control me anymore and I feel better about it. I don't know exactly why, but I feel my existence in this world is not limited to what is physically attached to me (brain included). I feel that "I" am just attached to my physical existence. Just have to try and find out who I am.

Edited July 25, 2009 by Improvision

[Phi for All]

Nope...

 

Evidence that can show what happened.

You don't think a predator superior to Cro-magnon and Neanderthal could have wiped them out, leaving evidence of superior weaponry marks on their crushed bones and skulls? Do you have a better answer than, "Nope"?

 

It was mentioned before and you ignored it. There *is* evidence that Cro-magnons and Neanderthals were often killed by superior weapons, so it's not unlikely they were killed by superior Homo Sapiens.

 

It would make sense that a higher number of dying members of a species than the number of births would lead to the species becoming extinct.

Yes, it would.

There has to be some reason as to why they are dying and are not reproducing.I have not seen the reasonable cause of this effect.

You said it yourself, it wasn't that they didn't reproduce, they just died at a faster rate than they reproduced. Their have been studies that show that more modern humans killed them.

[Improvision]

You don't think a predator superior to Cro-magnon and Neanderthal could have wiped them out, leaving evidence of superior weaponry marks on their crushed bones and skulls? Do you have a better answer than, "Nope"?

 

It was mentioned before and you ignored it. There *is* evidence that Cro-magnons and Neanderthals were often killed by superior weapons, so it's not unlikely they were killed by superior Homo Sapiens.

 

Yes, it would. You said it yourself, it wasn't that they didn't reproduce, they just died at a faster rate than they reproduced. Their have been studies that show that more modern humans killed them.

They could have, but we don't know that they did. Lions can kill hyenas, but they generally avoid each other.

 

There is evidence that members have been killed, but no evidence that they all died from being "killed".

[insane_alien]

nobody said they all died from being killed. just more of them.

 

it wasn't as if they vanished overnight, it took millenia for them to die out.

[Phi for All]

They could have, but we don't know that they did. Lions can kill hyenas, but they generally avoid each other.

 

There is evidence that members have been killed, but no evidence that they all died from being "killed".

Why do they *all* have to die the same way? Isn't attrition from various sources, including predatory higher Homo Sapiens, sufficient for extinction? I'm not sure why you are being so picky here. Not all extinctions are as "single-source" as the Dodo.

[Improvision]

Why do they *all* have to die the same way? Isn't attrition from various sources, including predatory higher Homo Sapiens, sufficient for extinction? I'm not sure why you are being so picky here. Not all extinctions are as "single-source" as the Dodo.

I didn't say it was "single source", now did I?

 

I wanted to know what led to the ultimate extinction. No evidence shows a complete killing off. If they all weren't killed, then something else was involved that would keep them from reproducing.

[insane_alien]

nothing kept them from reproducing, they just died more often than they gave birth.

 

if a population has a birth rate of 100 children per thousand population per year and a death rate of 101 deaths per thousand population per year then they are going to die out.

 

you seems to assume thatthey just stopped reproducing rather than had an excessive death rate.

 

to answer your question, you can't reproduce when you're already dead.

[Improvision]

nothing kept them from reproducing, they just died more often than they gave birth.

 

if a population has a birth rate of 100 children per thousand population per year and a death rate of 101 deaths per thousand population per year then they are going to die out.

 

you seems to assume thatthey just stopped reproducing rather than had an excessive death rate.

 

to answer your question, you can't reproduce when you're already dead.

That isn't going to prevent the living from having sex.

[insane_alien]

no, and i already said that it didn't.

[Phi for All]

I didn't say it was "single source", now did I?

You said, "There is evidence that members have been killed, but no evidence that they all died from being 'killed'". You seemed to require a single source. Honestly, I don't know why the several known answers for the Cro-magnon and Neanderthal demise, taken in toto, aren't good enough for you. You seem to have a reason you're not sharing why you think the evidence is wrong.

 

I wanted to know what led to the ultimate extinction.

Extinction doesn't have to be ultimate. There is a male Pinta Island tortoise in the Galapagos that is the last of his kind. When he dies, the species will be extinct.

No evidence shows a complete killing off. If they all weren't killed, then something else was involved that would keep them from reproducing.

Do you understand the fact that if a species has fewer births than deaths, it will die off eventually even if it keeps reproducing? At some point, the last female gives birth and there is no opposite sex to reproduce with, sealing the fate of the species. Now how are we going to have concrete evidence of an event like that? Edited July 25, 2009 by Phi for All
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[Sisyphus]

We don't know anything about the conditions they were living in.

 

Actually, we know a lot about it. But you'd have to ask a paleontologist about that.

 

I assume you mean one species is transit another species.

 

If by "transit another species" you mean evolve into something different, then yes. By definition, our "ancestors" didn't go extinct, because we're still here.

 

I saw a tv program a while ago where foxes were being bred in captivity. Outside of their natural habitat, each successive generation of pups were less and less aggressive towards people and they started to have less of a camouflage pattern in their fur. It seemed as if somehow there was an inner consciousness in the animals that had become aware of the environment they were in and influenced the DNA and change in the physical and mental traits in their offspring.

 

That isn't what happened. It was artificial selection. Only the least aggressive foxes of each generation were permitted to breed. Over many generations, they became naturally much friendlier towards humans. The changes in their appearance were unexpected, the result of genes tied to the ones that made them less aggressive.

 

I see myself being aware of my thoughts and being able to control them. I choose what I want to think about and I choose hoow I am going to act.

 

I was having sex a few years ago with women I didn't even care for. It felt dirty. I decided that I want to stop and find a real relationship. I have sexual urges, but they don't control me anymore and I feel better about it. I don't know exactly why, but I feel my existence in this world is not limited to what is physically attached to me (brain included). I feel that "I" am just attached to my physical existence. Just have to try and find out who I am.

 

I don't see how this is related to the rest of this thread. Please explain.