Why are our supposed ancestors extinct?

[CharonY]

The thing with science based discussion is that they should be based on established facts. What you consider as a matter of semantics is in fact a severe misunderstanding of some of the basic concepts of evolution.

So in closing what I’m trying to say is: yes environment and evolution do have a relationship (influence on each other) but still stand alone indifferent of each other.

 

This, for instance, is clearly wrong. As others pointed out, evolution does not happen in a vacuum. It is the result of the interaction of a population (or individuals thereof) with a given environment. Where you go wrong is thinking that the environment directly tinkers the genome of the individuals. This is not the case and it is not merely a matter of semantics. However, depending on the environment, certain individuals will propagate more efficiently than others. This is the very core of natural selection. If there was no influence of the environment there would essentially only be sexual selection, which, as already pointed out, is merely one of a number of mechanisms.

 

We encourage everyone to educate themselves, or to ask specific questions on a given subject. But we will not encourage wrong assumptions. You are entitled to make statements, but we will point out errors. In the end, this is how one learn things. I am sorry, but science is not an opinion.

[Edtharan]

in their ability to live, to maintain their life, to stay alive.

 

i.e. the amount of sweat evolution put into them, as survival is evolution's handiwork.

 

 

IMHO, this is a fallacy, these two metrics are the same.

 

Q:

why has coordination been introduced, if not to be well adapted?

 

intellectual capacity is the finest form of evolution, of "adaptation", and the holder of such trait can be considered to be the most advanced and ccomplex.

 

because intelligence is able to replace any other traits missed out, that is why humans are dominating the earth, not monkeys, and it is monkeys who are in zoos, not humans, and if a meteor was going to strike the earth, humans can go into space or under water like fish and dolphins, not monkeys.

 

humans, with their intelligence, are the most able to adapt.

 

they are the most complex and advanced.

 

a black belt karate master is nothing in front of an old lady with an AK-47.

that is an analogy, for the AK-47 can be useless in other situations where karate is more useful.

intelligence is not, it is a master key, evolution's finest.

 

as i said, intelligence i\fits all enviornments, even those not intended for life(like space).

 

but i'm interested in hearing of the environment that made intelligence a must, instead of climbing trees.

(not to mention that for those who climbing trees is a necessity for, they only need the first 6 to 7 years of their life to develop such ability, the human brain and body is capable of feats close or similar to those of many animals. climbing trees like monkeys, running fast like four legged animals, staying underneath water for so long nearly like some underwater mammles, relatively spaeking of course.)

Your entire post can be summed up as Homo centralism. That is the world revolved around us, that we are the pinnacle of evolution. Wee, what will be the pinnacle of evolution 1,000,000 years from now? It won't be the same as us, that is for sure. So we are not the pinnacle of evolution. But, if we are not the pinnacle of evolution, then what is?

 

Answer: nothing.

 

Evolution is NOT a directed activity. There is NO universal scale that measures how better all things are in relation to all other organisms.

 

Let me put it to you like this: If Humans are the pinnacle of evolution, then why do we still die from infections? Surely, being so well evolved, and having such a great intellect, we should be able to survive any attack from "Lesser" organisms.

 

So then, why do we die from infections? Is it because we are the pinnacle of evolution? Or is it that there is no such thing as the pinnacle of evolution?

 

Ahh, "But!" you might say, our intellect has enabled us to eradicate infections, like Small Pox. Well, no.

 

Small Pox still exists, and we have not eliminated a single species that infects us. In fact, all our attempts to eradicate these organisms have actually made them tougher and they ahve evolved defences against all the products of our (so called) "Intellectual" might.

 

In terms of survival, we are about on par with any infectious agent, and loosing ground rapidly.

 

So, if our "Intellect" is such a huge advantage that it makes us the "Best", then why are we having so much trouble fighting off the (least evolved) single celled organisms.

 

No, despite all our best efforts, we have not been able to eliminate a single single celled organism or virus from the face of the planet. At best we can get a temporary stalemate until they develop resistance to our current efforts. Even with our "intelligence" we are not "Better" than them, we are (at best) a struggling equal.

[Mr Skeptic]

intellectual capacity is the finest form of evolution, of "adaptation", and the holder of such trait can be considered to be the most advanced and ccomplex.

 

because intelligence is able to replace any other traits missed out,

 

...

 

humans, with their intelligence, are the most able to adapt.

 

An interesting thought, but consider that our intelligence alone would get us nowhere. We have an innate ability for language, that seems to allow us to use "real language" (context free language). We have an innate capability to use tools, to treat them as an extension of our body, to understand what others are using them for. We are able to mimic others. We have well-developed theory of mind, allowing us to understand others. We have empathy, allowing us to care for others. We have a variety of social instincts, without which we could never form societies. As well as other useful traits.

 

In short, we have an almost magical combination of traits that allow us to excel. Some of them are related to intelligence, in that the ability requires some intelligence to use, but they are by no means the only way that intelligence could be applied.

 

Imagine if we were 10 times as smart as we are, but had anti-social properties. Or lacking one of the other properties.

 

But with intelligence, society, communication, and tool use, we can pass on the fruits of our intelligence, work together, and make useful tools. This gives us absurd adaptive power (and also the capability to destroy ourselves). But lacking one of these, we wouldn't even be in the stone age.

 

However, for other species, intelligence does not produce the extreme adaptability that it does for us. As such, I don't think it could be used to measure an species' fitness. However, it seems that intelligence does correlate very well with an individual's overall health, and various species seem to make use of this in mate choice.

[Mythranil]

 

Evolution is NOT a directed activity. There is NO universal scale that measures how better all things are in relation to all other organisms.

 

 

I would argue that evolution does have direction, in a sense, that is an effect of our environments. It's been shown that organisms evolving continents apart but living in the same or similar environmental niches will display convergent evolution wherein they evolve similar physical traits; there are many examples of this, but perhaps the best modern-day examples stem from the Australian marsupials, most of which have counterparts on other continents, yet they have not possessed a common ancestor for a very long geological timeframe. There's also the evolutionary convergence of monkeys in South America and some of the apes and monkeys in the old world.

 

Simon Conway Norris is a proponent of this mode of thought; he goes further to suggest that evolution is, in a way, directed and driven by our environmental niches with an endgoal in mind, if you will. We're all evolving to develop traits that help us adapt to our environment, and the only reason we haven't stopped evolving is because our environments continually undergo change. He also claims that intelligence and consciousness are an endgoal of any evolutionary niche, and this is because it is the ultimate tool of choice in terms of adaptation. I'm not sure if I support the last idea of his or not, but I thought I'd throw that out there anyway.

 

I'm sure there are plenty of other examples of convergent evolution out there today; I'm not as familiar with modern life forms as I am with past life forms.

 

On a somewhat related note, given that premise, do you suppose that humans are artificially altering the genetic constituency of populations based solely on the idea that we are causing climate change (and that too, of course, is still open for debate as well)? I don't think there's a straight and narrow path for evolution, by any means, but by changing the environmental niches on the planet, we have evolution move in a different direction than it would have if humans or their hominid ancestors didn't make the scene.

 

If our effect on global climate change is as drastic as some would claim, and we end up increasing global sea levels and cause land masses to dry up and turn to desert (a la Triassic period), do we cause all life in the seas to generally converge to one endpoint, and terrestrial creatures to another? Of course, these global climate changes would have to be extreme and semi-permanent for something of this magnitude to happen; but hypothetically, what if we did reduce our effective number of ecological niches to just these two? (I understand there are sub-environments, ie, coastal, brackish, delta, etc.; let's forget about those for the sake of the concept).

[Mokele]

I would argue that evolution does have direction, in a sense, that is an effect of our environments. It's been shown that organisms evolving continents apart but living in the same or similar environmental niches will display convergent evolution wherein they evolve similar physical traits

 

But that's not really a *goal*, that's just similar selection pressures. A goal, in the sense it's often used, is something beyond these pressures, some direction that cannot be explained simply by adaptation to local environmental conditions.

[Mythranil]

But that's not really a *goal*, that's just similar selection pressures. A goal, in the sense it's often used, is something beyond these pressures, some direction that cannot be explained simply by adaptation to local environmental conditions.

 

I couldn't agree more; Simon Conway Morris seems to think there truly is an end goal - or maybe I misunderstood his point on the matter - but I have a hard time believing that. I don't see why there would be any reason for an evolutionary goal. What could possibly be a controlling factor on that? We'd have to start considering things like Creationism, perhaps... And that's a whole other ball of wax.

 

In another thread I commented on the fact that whales were originally land-based mammals. If evolution had an end goal in mind, why take a detour and bring life out of the sea, evolve lungs and legs, then send them back to the sea again? Cut out the middle man... Unless it's some huge evolutionary advantage to have lungs in the ocean. Does anyone know if it's more efficient to breathe oxygen from the air than from water..? Maybe that's why, in part, they can grow to such sizes.

 

But even so, is that really a necessity for evolution? Isn't it more efficient to keep a smaller body size so you need less food resources?

[Mokele]

Unless it's some huge evolutionary advantage to have lungs in the ocean. Does anyone know if it's more efficient to breathe oxygen from the air than from water..? Maybe that's why, in part, they can grow to such sizes.

 

Actually yes, air is much easier to breathe. Aside from being a less dense fluid (therefore less work to push across respiratory surfaces), it has much, much higher oxygen content. That's why some very small, permeable-skinned amphibians can get away with being totally lungless (the Plethodontid salamanders), but in the water, gills or lungs are absolutely needed, and effective cutaneous respiration is really only possibly at tiny sizes and in cold water (more dissolved O2).

 

Breathing air is also the only way for an oceanic critter to be completely endothermic. If water has to pass over gills, the blood in the gills will assume water temperature. Some species of fish can be regional heterotherms via muscle heat and countercurrent exchangers in the vasculature, but never true endotherms.

 

But even so, is that really a necessity for evolution? Isn't it more efficient to keep a smaller body size so you need less food resources?

 

Depends on the species. Small does mean less food, but for species that lay many eggs, it can mean reduced number of offspring (which is why female turtles, snakes and frogs are often larger than males). For endotherms like whales, large size also means less skin area per unit volume, reducing heat transfer and allowing them to live in cold waters (where there's more O2 and nutrients, thus more plankton).

[Edtharan]

I would argue that evolution does have direction, in a sense, that is an effect of our environments. It's been shown that organisms evolving continents apart but living in the same or similar environmental niches will display convergent evolution wherein they evolve similar physical traits; there are many examples of this, but perhaps the best modern-day examples stem from the Australian marsupials, most of which have counterparts on other continents, yet they have not possessed a common ancestor for a very long geological timeframe. There's also the evolutionary convergence of monkeys in South America and some of the apes and monkeys in the old world.

You are saying that animals in similar niches will evolve to be similar. That is pretty much accepted, but it doesn't give proof of directed evolution.

 

Similar niches, have similar selection pressures. That is why we recognise them as similar niches, if they had different selection pressures, then they would be different niches.

 

There are adaptations that work (for a given selection pressure) and adaptations that don't. It is therefore not surprising at all that given the small number of possibilities that an organism can adapt to to meet the requirements of the niche, that different organisms in different locations but the same niche evolve similar adaptations.

 

Again, this is not evidence of directed evolution, only that there is a finite number of ways that an organism can adapt to a given set of selection pressures.

 

Simon Conway Norris is a proponent of this mode of thought; he goes further to suggest that evolution is, in a way, directed and driven by our environmental niches with an endgoal in mind, if you will. We're all evolving to develop traits that help us adapt to our environment, and the only reason we haven't stopped evolving is because our environments continually undergo change. He also claims that intelligence and consciousness are an endgoal of any evolutionary niche, and this is because it is the ultimate tool of choice in terms of adaptation. I'm not sure if I support the last idea of his or not, but I thought I'd throw that out there anyway.

I would strongly disagree here. Intelligence is not an ultimate end goal of all niches. If there were so, then bacteria, who reproduce much faster than us (around 220,000 times faster ) would be far more intelligent than us. But this is not so.

 

It is more likely that an animal will become more specialised in time (better to fit the requirements of the niche). If an animal is well adapted for its niche, then it does not have need for much intelligence as its behaviours can become hard wired and so reduce the amount of brain capacity needed to perform those behaviours. This makes the responses much faster and it takes less energy to operate a smaller brain.

 

So, as an organism becomes more adapted to the niche, there is actually a selection pressure to reduce brain size and make the responses more specialised.

 

Humans are interesting in that we are omnivores and we are not adapted for a specific niche (this has also allowed us to spread to many more environments as well). Omnivores tend to be opportunistic feeders as they have evolved in a situation where a regular type of food is not reliable. They have been forced to eat a variety of things to get the nourishment they need to survive.

 

Also, being opportunity feeders, they have to be able to seek out that food and investigate new foods. This requires intelligence as you have to be able to discriminate between food and not-food and work out ways of determining this in ways other than trial and error (trial and error is disastrous if you eat something that is poisonous).

 

So when there is many different type of foods, but any one type (or even a few types) are not plentiful enough to support an organism, then omnivores are at an advantage. However, because an organism that has become specialised is... specialised, they are better at exploiting their given food source than an omnivore is. This means that a specialised organism has an advantage over omnivores when there is only a few types of foods available, but there is plenty of any given food.

 

So when an organisms becomes specialised, it no longer has to worry about sorting out what is or is not edible as it has a plentiful source of their given food and they therefore do not need the intellectual capacity for this exercise (and it is therefore selected out as big brains use lots of energy).

 

So, Norris 's belief is pure hubris: Because we are successful and we are intelligent, then intelligence must be the end goal of evolution.

 

This is not so. Evolution is nothing like this at all. It selects for the immediate environment and nothing else. It is incapable of working out what the future holds (well for starters, evolution has no brain with which to do this with as it is just an algorithm) and it has no memory of the past (again no brain and there is nothing in the algorithm of evolution that references the past either).

 

This means that there is no way for evolution to plan for the future, or remember the past. A Direction requires a start point and an end point. As the process that is evolution has nothing in it that uses (or requires) a start or end point (it only acts on the immediate), then it is mathematically speaking impossible for evolution to have a direction or and end goal.

 

I'm sure there are plenty of other examples of convergent evolution out there today; I'm not as familiar with modern life forms as I am with past life forms.

 

On a somewhat related note, given that premise, do you suppose that humans are artificially altering the genetic constituency of populations based solely on the idea that we are causing climate change (and that too, of course, is still open for debate as well)? I don't think there's a straight and narrow path for evolution, by any means, but by changing the environmental niches on the planet, we have evolution move in a different direction than it would have if humans or their hominid ancestors didn't make the scene.

 

If our effect on global climate change is as drastic as some would claim, and we end up increasing global sea levels and cause land masses to dry up and turn to desert (a la Triassic period), do we cause all life in the seas to generally converge to one endpoint, and terrestrial creatures to another? Of course, these global climate changes would have to be extreme and semi-permanent for something of this magnitude to happen; but hypothetically, what if we did reduce our effective number of ecological niches to just these two? (I understand there are sub-environments, ie, coastal, brackish, delta, etc.; let's forget about those for the sake of the concept).

As I sated above, evolution has no way of working out the future, or examining the past, so it is impossible for it to have a direction.

 

As you said: "I'm not as familiar with modern life forms as I am with past life forms", this shows that you ahve a memory and so can think in directions. Evolution does not have a memory and so can not "think" (it also doesn't have a brain in which to think either) in terms of direction.

 

Evolution is not directed in any way. To suggest so means that evolution has to ahve the capacity to "think" and as it is a blind process it has no capacity to think.

 

Yes. Organisms adapt, but they only adapt to the immediate environment and even then it comes down to the ability of one organism to out compete another. To put it in a metaphor: You don't have to run faster than the lion, you only have to run faster than the slowest guy.

 

Evolution is not necessarily about being the best adapted, but it is more about not being the least adapted.