Evolution confusion

[Garrettguy457]

the other day I was asked a question about evolution that I feel has an easy answer yet i just don't know. If evolution is a long process of change, then why aren't there any half-chimp/half-human? Or why are there chimps still left today that aren't human?

[the tree]

If evolution is a long process of change, then why aren't there any half-chimp/half-human?

Humans didn't evolve from modern day chimps but they do share a common ancestor, long extinct along with the generations in between where the species grew further and further apart.

Or why are there chimps still left today that aren't human?

There's no reason why there wouldn't be. When a species is more or less adapted to it's environment, natural selection has a fairly limited influence. A chimp displaying human like characteristics wouldn't have an increased chance of survival or chance to reproduce - so it wouldn't be a variation that would last.

[Garrettguy457]

Thank you very much. I understand much better now,

[iNow]

I think the tree already addressed your question, but just to add to what he said...

 

The question is really baseless. You have cousins, right? People who were born as children to your parents siblings? Well, how come there are no people in between you and your cousins (like "half-cousin/half-you")? Because, it's a stupid question.

 

For the second question (why are there still apes), it's another somewhat baseless question. It's like asking "If Americans and Australians all mostly came from Europe, why are there still Europeans?" It's just completely irrelevant.

 

 

Also, here's a good site with some FAQs that I think will help you to make the idea even more clear in your mind:

http://www.pbs.org/wgbh/evolution/library/faq/cat03.html

 

 

I really hope this helps, and I'm glad you've taken the time to ask. That shows that you have a genuine desire to understand, and I commend that.

[Garrettguy457]

those analogies were absolutley awesome. Thank you very much for those.

[Mr Skeptic]

the other day I was asked a question about evolution that I feel has an easy answer yet i just don't know. If evolution is a long process of change, then why aren't there any half-chimp/half-human? Or why are there chimps still left today that aren't human?

 

Evolution is a random process, that goes in all directions at various speeds. The stupid monkey --> caveman series of pictures is a poor description, as it leaves out all the branching that happens at most steps. In most cases, both branches of the tree change. In some cases, there is little change and such creatures are called "living fossils".

 

The study of such evolutionary relationships is called systematics.

[Sin]

I think the tree already addressed your question, but just to add to what he said...

 

The question is really baseless. You have cousins, right? People who were born as children to your parents siblings? Well, how come there are no people in between you and your cousins (like "half-cousin/half-you")? Because, it's a stupid question.

 

For the second question (why are there still apes), it's another somewhat baseless question. It's like asking "If Americans and Australians all mostly came from Europe, why are there still Europeans?" It's just completely irrelevant.

 

 

Also, here's a good site with some FAQs that I think will help you to make the idea even more clear in your mind:

http://www.pbs.org/wgbh/evolution/library/faq/cat03.html

 

 

I really hope this helps, and I'm glad you've taken the time to ask. That shows that you have a genuine desire to understand, and I commend that.

 

I want to thank you for those statements, i had wonderings on how to combat relatives who say things such as this also. I had to read over your analogies a couple times, but when i got them i fully understood.

[pioneer]

Darwin studied animals in Galapagos and found old species still in existence that were thought to come from the age of the dinosaurs. These should not still exist according to the logic. Conceptually, there should also be pockets of ape-human hybrids if these found a place of isolation and were adaptive to the environment. But we haven't found any yet.

 

Monkeys exist, which are lower than a potential monkey-human hybrid. You would expect the hybrid, with all its extra smarts, should have selective advantage. But since we can't find any examples, this shows that often a lower common denominator can have selective advantage.

 

Many people are confused by this, since the definition of evolve appeared a century before Darwin and meant increasing complexity or increasing advancement. I am sure sure Darwin knew this and implied this, or else he was trying to pull the wool over people's eyes, knowing most will assume the conventional meaning of the word.

 

Evolution and selective advantage creates this image in the minds of the layman, but often evolution can go backwards in terms of advancement, and still be called evolution. When the child sees the picture series of the ape starting to walk upright and losing fur and becoming closer and close to modern man, doesn't that sales pitch progress? That is why I am confused. Why don't the pictures show a random series with setbacks to make it more in line with the theory?

 

Personally. I think we should redefine evolution to mean forward progress, in the historical tradition before Darwin, and iron out what we mean by forward progress. Then the theory can become more rational. Now it can go both ways and confuse the layman.

[Mokele]

Pioneer, your entire post is based on a simple misconception - that there is such a thing as "better" or "forward progress", when in truth, neither exist beyond the most immediate level.

 

Consider bears - one group has adapted to cold regions (polar bears, grizzlys, etc.), while another has adapted to warm regions (sun bears, sloth bears, etc.). Which is "more advanced"? Both are perfectly adapted to their environments.

 

Are humans "better" than monkeys? Well, we have civilization and such, but our big brains and bodies are more expensive. If an asteroid struck, we'd probably die out while monkeys survive.

 

The definition of evolution does not involve directionality or progress because there's no such thing, and any appearance of it is an illusion due to bias on the part of the viewer.

 

Mokele

[Ophiolite]

What Mokele said, plus:

Personally. I think we should redefine evolution to mean forward progress, in the historical tradition before Darwin, and iron out what we mean by forward progress.

Good luck with that.

Or, to put it another way: no chance. It is a moving target. Change the environment and what was 'forward' becomes 'backward'.

Then the theory can become more rational. Now it can go both ways and confuse the layman.

Scientific theories are not formed for the benefit of the layman, but as a means of better understanding some aspect of the universe. It requires hard work and an education to take maximum advantage of what has been discovered to date. Your proposal is simply a form of dumbing down. We should instead be smarting up.

[Sayonara]

Evolution is a random process, that goes in all directions at various speeds.

You have to be very, very careful with phrases like this. The casual reader might take this to mean that evolutionary effects within a species act randomly, and they most certainly do not.

 

From the context of your post I think that what you mean to communicate is that the overall progress of evolution as it occurs in many species is unpredictable on large scales. Is that more or less it?

[Mr Skeptic]

I'd say that evolution is even less predictable on small scales. On the small scale, natural selection is almost blind to minor unfitness that would be likely be eliminated at larger scales.

 

Yes, my main point was to explain that there is no "forward" evolution, that evolution does not have one direction nor is trying to reach some "ideal organism". The branching description that I gave is in part that, in part a description of cladograms.

[puddlejumper]

But how to explain the Cambrian Explosion? I think that the evolution only works in periods, and till nowadays, our science couldn't explain what was happen during the periods, that is why there are so many faults in archaeology research

[D H]

Evolution is always at work, but the rate of change is not constant. Evolution can proceed extremely quickly (quickly on a geological timescale) when a new capability evolves or when the environment drastically changes. The Cambrian Explosion is the most extreme example of heightened evolutionary change. There are several others. When the environment remains pretty much constant over a long period of time, evolution can conspire against change. Mutations are much more likely than ever to be suboptimal as the extant species have already become optimized for the steady-state environment.

 

Regarding archaeology, I'll agree that archaeology has a hard time explaining what happened in the Cambrian Explosion, but that is because that is outside the domain of archeology. Archeology, being a very specialized field, is concerned only with what happened in the last million years or so, and only to a small set of species (humans and their predecessors).

[Mokele]

It's also worth noting that the Cambrian "explosion" actually took about 50 million years (almost as much time as has passed since the dinosaurs died). If you compress any events to that degree, it'll look like an 'explosion'.

[johnbrandy]

Evolution is a useful and interesting concept. Still, there is no adequate explanation why any species harbored the tendency to evolve, change and adapt. This appears to be the greatest mystery of evolution. Certainly, some as of yet, unknown force, intelligences, or principle must be interacting with biological life to bring this about. Sure, my opinion is not, in any strict sense, science. Much of science resulted from the asking of questions which, at the time, lacked scientific foundation. The tendency to evolve, change, and adapt must be subject to scientific scrutiny, if we hope to achieve a more complete understanding of evolution. I do not pretend to know where scientist might begin this quest. Moreover, the "answer" may lie outside of scientific inquiry, as, I suspect, much of our current scientific exploration.

[Sisyphus]

Still, there is no adequate explanation why any species harbored the tendency to evolve, change and adapt.

 

Actually, that's one thing that's not mysterious. An imperfect self-replicator + natural selection = evolution.

[iNow]

Indeed.

 

John - Your logic is somewhat faulty, as you implicitly assume that evolution MUST be a directed process, or have some goal/intent. I don't mean this as an insult, so please understand that I'm really trying to help, as it's actually quite common to see this exact line of thought when people discuss evolution. The thing is, it's not a directed process, there is no "goal" to be sought.

 

It's just that organisms are born, some do better than others under the given circumstances and environment, and then eventually you have more of those who did better and less of those who didn't fair so well. It really is that simple.

[scrappy]

Evolution is a useful and interesting concept. Still, there is no adequate explanation why any species harbored the tendency to evolve, change and adapt. This appears to be the greatest mystery of evolution.

No, john, there is no mystery at all. Actually, Malthus had the answer even before Darwin got it: populations naturally produce more offspring than can be sustained by their habitats. Depending upon the shifty conditions imposed by a habitat, only the adaptable ones survive. Survival of a population, then, becomes a matter of descent with modification. That's all you need to know to solve your mystery.

[pioneer]

I understand, that evolution, as written, is not concerned with progress in an objective sense of systems that improve over time, which if brought back into time, would have selective advantage over an earlier version of the same animal. For example, if we could take modern humans and place them 3 million years ago, according to the theory, there is no objective measure of forward progress. Selective advantage will not go to the modern man since he is not more advanced. It would be a crap shoot, as to who will have selective advantage. I would bet on modern man if you give me 50/50 odds, since he is an advanced version of model 1.0. The older version 1.0 is better with older systems much like old cars had stronger bodies with thicker steel construction. But under the hood there is no comparison since evolution meant forward progress.

 

We would also need to do it the other way. We will take a pre human from 3 million years ago and bring him into modern culture and let him adapt to see if this is also random. I will still use the objective standard of progress when I place my bet.

 

I think I figured out the problem. If we look at all of evolution, from when life was simple chemicals like methane and ammonia, up to the present and plot that data from 0 to 100, Darwin's original "origin of species", was a good fit for species data, which is like the data from 50-100. But just because the theory fit that data it does not mean it can extrapolate all the way to 0. If we don't start at the origin, the best curve may fit the subset of data but may be transposed vertically.

 

Later an addendum was added to the theory when microscopic life was added to macroscopic observations, via genetic theory. This creates the best fit of the data from 20-100 but does not intersect the origin. It is not clear if it is the final curve since there is no requirement that it has to intersect the origin. This potentially, "floating curve" may fit the data from 20-100 perfectly, but has to intersect the origin to be finalized. If we use the theory and extrapolate it back, we may get to 10 or replicators but not to the origin. That told me, just as Darwin needed genetics added to use more of the data, genetics may also need something more fundamental added to get to the origin.

 

Where I looked was water and hydrogen bonding since water is the majority component and everything in the water has to follow the potential associated with water. Hydrogen bonding is a variable that is common to both water and active bio-materials. If you stick lipids in water and shake, the aqueous potential makes a membrane. The interaction with water intersects the origin, since even ammonia or methane in water are under aqueous potentials and h-bonds.

 

Intersecting the origin does leads to some some conflicting conclusions, since it touches all the data from 0-100 and not just from 20-100. Progress based on the curve from 0-100 is a function of an energy balance. Energy considerations will result in bi-layer membrane from lipids. It is not random with cubic membranes just as likely. These would be too high in energy and would shift into the spherical. Once that potential is settled, there is a new milestone for progress.

Edited February 13, 2009 by pioneer

[iNow]

I understand, that evolution, as written, is not concerned with progress in an objective sense of systems that improve over time, which if brought back into time, would have selective advantage over an earlier version of the same animal.

This is inaccurate. Evolution does not mean "improve over time." It is simply about adaptation to changing conditions. Things don't really just get "better," as there is no objective benchmark for "better." They get "more adapted to the environment."

[Mokele]

I understand, that evolution, as written, is not concerned with progress in an objective sense of systems that improve over time, which if brought back into time, would have selective advantage over an earlier version of the same animal. For example, if we could take modern humans and place them 3 million years ago, according to the theory, there is no objective measure of forward progress. Selective advantage will not go to the modern man since he is not more advanced. It would be a crap shoot, as to who will have selective advantage. I would bet on modern man if you give me 50/50 odds, since he is an advanced version of model 1.0. The older version 1.0 is better with older systems much like old cars had stronger bodies with thicker steel construction. But under the hood there is no comparison since evolution meant forward progress.

 

Wait, at first you seem to get that evolution isn't forward progress, but at the end of the paragraph, you imply it is? Why the disconnect?

 

If we look at all of evolution, from when life was simple chemicals like methane and ammonia, up to the present and plot that data from 0 to 100, Darwin's original "origin of species", was a good fit for species data, which is like the data from 50-100. But just because the theory fit that data it does not mean it can extrapolate all the way to 0. If we don't start at the origin, the best curve may fit the subset of data but may be transposed vertically.

 

What on earth are you graphing? All you're doing is drawing random curves through made-up numbers.

 

Mokele

[scrappy]

This notion of evolutionary progress is often confused, I think, with evolutionary diversification, which requires only the random walk principle to explain. This graph suggests a macro-diversification of 3 marine families per million years over the past 250 millon years:

 

(source)

 

But this trend toward diversification is only a random function and not directed, which defeats any argument implying progress.

[Ophiolite]

Pioneer,

you seem to be asking evolutionary theory to account for the origin of life (the zero point on your curve). That would be faulty logic, would it not, or have I misunderstood your thrust?

[iNow]

A fun little video.

 

 

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