How come evolution?

Question

I do not understand why scientist continue to stretch the idea that human beings evolved from apes. If that is the case...why haven't I heard of a case where human beings are still being evolved from the apes.

Answer 1

It really doesn't work that way.

Organisms evolve in response to environmental pressures. So being hunted by a fast-running predator will be a pressure that will encourage the prey species to evolve a mechanism for avoiding the predator. These adaptions might be faster-running themselves, or climbing, or burrowing, or pack behaviour (banding together for protection).

The pressure that proto-humans were under is not the same as the pressure that apes are under now; the world has changed since then. Apart from anything else, humans are already here now, and we have evolved to fill our niche in the biosphere very well.

Also, since evolution only happens from generation-to-generation, and happens in tiny increments, slow-breeding species (like all the apes) take a *very* long time to evolve.
From the first appearance of "proto-humans" (Homo habilis) to the appearance of the first identifiable "modern man" (Homo sapiens) took around 2 million years.

All organisms are evolving all the time (including humans). But it's not like humanity is the "target" of evolution; we're just a step along the way.
_______________________________________________
Edit (to respond to Anna's points):

1. While stating the DNA only allows so much variation from person-to-person, she is failing to understand that there are well-established mechanisms for introducing *new* traits into a population. This mechanism is MUTATION.
The total "gene pool" of a population will change over time: some traits (disadvantageous ones) will become less frequent, others (advantageous ones) will increase in frequency, and (importantly) - through MUTATION - entirely *new* traits will be introduced!

2. The universe is, in fact, very old. Around 13.7 billion years old. This has been calculated by physicists and astronomers by a number of mechanisms, including the rate at which objects are receding from us (expansion of the universe).
The Earth itself is 4.5 billion years old. This has also been calculated from a number of sources, like radio-dating of ancient rocks, and measurements on the age of the solar system itself.
The idea that there is too little dust on the moon was based on inaccurate measurements about how much dust there was around to accumulate. These measurements have long since been re-made, and agree well with the amount of dust on the moon:
http://www.talkorigins.org/indexcc/CE/CE101.html

3. The second law of thermodynamics does not in fact work like that. It only works in a *closed* system - which is to say, a system where no more energy is being added. The earth has a large source of new energy - it is called The Sun!

4. Her argument here is against ABIOGENESIS: how life *began*. This has nothing to do with evolution, which is the study of how life *changes* over time. There *are* hypotheses for how abiogenesis occurred, but they remain widely-disputed and hotly debated, especially among scientists.

5. And her final point has nothing to do with evolution at all. There are 112 elements *currently known*, but there may be more (in fact, more are being discovered regularly). And the structure of these atoms are dictated by well-established physical rules that allow for certain arrangments.

Finally - she refers to a version of the "watchmaker paradox" arguement (which she also mentions earlier). Evolution doesn't work like that; it is not like things randomly arranging themselves into a watch or into a shoe.
To quote another anti-evolution arguement: "evolution is like sending a tornado through a junkyard and getting a boeing 747 out the other end".
No it isn't. Evolution is like sending millions of tornadoes through millions of junkyards. You examine what you have at the end and, if anything looks anything like any bit of a 747, you keep it, otherwise you junk it. Then you send the tornadoes through again, and repeat. Millions and millions of times. Do this long enough, and you'll have a 747. Or at least, you'll have something that can fly.
_______________________________________________
Further edit to Anna's responses (whee, this is fun, isn't it):

1. Down's Syndrome is becoming more common for a couple of reasons: humans in the developed world are having children later, which increases the likelihood of Down's Syndrome (and several other developmental defects). Also, we are getting better at caring for those born with Down's Syndrome, so they do not die as early as they used to.

2. Not in fact "made to fit", no. Ideas on the formation of planets and solar systems are undergoing refinement, like all aspects of science - evolution included.

3. I'm afraid that plenty of energy from the sun does in fact reach us. Yes - we receive very little of the energy actually emitted from the sun (thankfully), but it is plenty enough for plants to use in building themselves. And that is the route by which "new" energy enters the earth's biosphere. Your suggestion would be a bit like being surprised that a cake bakes if you apply heat to it. The cake is not a closed system, because heat is entering.
And the law of the conservation of energy does, I'm afraid, work only in a system where no energy is being added. Think about it.

4. Again, abiogenesis has nothing to do with evolution. The origins of life are *not* within the theory of evolution.
The possible mechanisms of abiogenesis are *much* more hotly disputed that evolution:
http://en.wikipedia.org/wiki/Abiogenesis

5. The observation that the constants of the universe are structured just "exactly so", in such a manner that life as we know it can exist is called the "anthropic principle". It is true that, if any of the universal constants (the speed of light, the gravitational constant, etc.) were even slightly different, then we could not exist. However, this also has nothing to do with evolution.
http://en.wikipedia.org/wiki/Anthropic_principle
One thing I would ask you to bear in mind is that the Theory of Evolution makes absolutely no statement about the existance or otherwise of God. It is perfectly possible to believe in God, and believe in evolution. The only thing that evolution (and geology, and physics, and astronomy) disallow is a *literal* interprtation of the bible. God may well have created the universe, but he did so 13.7 billion years ago, not 4000 BC.

And for my final point:
The picking is done by "Natural Selection" in the case of organisms. Those that are fit to survive and breed will persist. Those that are not ... will not.
And there are "transitional forms". Plenty of them:
http://en.wikipedia.org/wiki/Transitional_fossils
For example, the archeopteryx, which has both bird-like and reptile-like features; it is neither fully a bird, nor fully a reptile, but is transitional between the two forms.

And in response to your responses to Anotherguy ;-)

1. As an example beneficial mutation: there is a 32 base pair deletion in human CCR5 (a chemokine receptor) that confers resistance to HIV.

2. I'm not sure what your point here is about spontaneous generation except to point out that scientific evidence and properly-designed experimental results trumps belief. Which is what the pro-evolutionists are saying.

3. When the sun burns out, or more accurately becomes a red giant in 4-5 billion years, unless we have found a way to leave the solar system, we will all die out. What has that got to do with evolution?

4. Lots to address here:
We all evolved from the simplest form of life. That's where it went to.
"Where did the first atom come from?" Again, I fail to see what that has to do with evolution.
And life coming from inanimate matter is - as I've stated before - ABIOGENESIS not evolution!
And the universe is expanding because space itself is expanding, not because more energy and matter are being created. Not the same thing: I can have an expanding dinner-plate without having more dinner on it.

5. "Who came up with the laws of physics" is not a question science can answer. It deals with a supernatural being, one (by definition) outside the laws of our universe.
So the existance or non-existance of God (or any other supernatural being) is not investigateable by science.
Like I said: all science can do wrt religion is say whether stories in holy books are possibly true or definitely untrue.

Finally:

I appreciate you making your points. And I do respect that you have kept religion out of it; you have not mentioned any specific creation myth, or anything similar. Neither have I, except the belief that some hold that the universe is only ~6000 years old.
No-one here is "pummeling you with questions", they are instead answering your points with reasoned objections, the same way you are answering their points with your thoughts.
Sadly, what you believe as "the Truth", and what I and others believe as "the Truth" are not the same. Naturally, I believe that you are incorrect, and I am trying to explain why this is so. We are not bullying you or anyone else.
The "point" behind these discussions is not neccessarily for us to persuade you to change your mind (though, from my point of view, that would be nice) - it is for others reading this Q&A section to see what the differences are, and what the arguements are for each side. They can then make their own minds up.

I hope that this does not put you off Y:A . This forum is much less "flame-war"-y that many other forums for discussing such differences. However - differences will remain, and people will argue.

Answer 2

For the same reason people are taught evolution in school, yet don't learn evolution.

Scientists don't think humans evolved from apes. And if an ape gave birth to a human, or anything other then an ape, it would actually disprove evolution.

Answer 3

Possibly because all the DNA and other evidence points to evolution.

You obviously have no idea how evolution works. Apes don't spontaneously turn into people. You can observe evolution in very short lived species like mosquitoes, but the changes occur over dozens of generations. Try looking up how elephants are being born that can't grow trunks, or the brand new species of mosquito that only lives in the London Underground. Try doing some reading into it. You might not ask questions that show why kids shouldn't be home schooled, or allowed to opt out of 'unchristian' biology lessons.

Answer 4

Scientists do not stretch anything. A certian evolutionary path, (such as ape-like ancestors to humans) is extremely unlikely to happen the same way twice, just as you are extremely unlikely to get dealt the same hand of cards twice, or lightning is extremely unlikely to strike the same place twice.

In reply to Anna:
1. DNA forms new varieties from mutations. Yes, most are harmful, which is why natural selection weeds them out. Occasionally, you get a beneficial one.

2. Moon dust? What are you talking about? That argument was discounted by creationists, because they didn't want to use such a rediculus argument. (see source) We have several methods of radiometric dating, all INDEPENDENTLY giving similar ages for things. Yes, they are reliable.

3. (Sigh)The second law only applies to closed systems. Yes, most of the sun's energy is pouring out uselessly into space, and yes, it will eventually burn out. What's your point? The small fraction we get is still enough to sustain all life on earth, and our system is still not closed. (that argument has also been discounted by creationists)

4. That's completely a straw man agrument. Go learn somehing about biology and physics. Then we can talk. The first life wasn't anywhere near as complex as even the simplest bacteria. It was just self-replicating molecules. It evolved into more complex forms over time. No one is claiming that a DNA molecule just spontaniously arose "by chance".

5. There's a limited number of elements because there's a limited number of combinations of protons and neutrons that are stable under the laws of physics. There is a virtually infinite variety of possible snowflakes, and so that is not a valid comparison.

Answer 5

Evolution is a process that takes thousands to millions of years to take a simple step sometimes. Yes, we do share many traits with the apes, but our two species are like two different branches on a tree. We both may have started with the same trunk, but over time one branch grew out from the other on it's own path, even though they still may remain close. Basically, if evolution is true, then humans were from a type of human-ape species that needed something new in order to survive the world and they devloped it. We didnt come from the apes you see today, but those of the past.

Evolution is a nice theory, and it will take a long time before it can be truly shown (not proved, but shown) to be true. And to me, it just makes a lot more sense than creation.

Answer 6

Wow!
Let me clarify...what you don't understand is the theory of evolution.

Let's cut to the chase...humans did not evolve from apes. The theory does not say that, nor does it imply that.

and species only evolve once.

There are just so many things wrong with your question, it is hard to know how to answer. So I will stop there....

Answer 7

(a) because primate evolution is supported by known facts, and (b) one can be true without requiring the other. You might want to do a little work in logic and logical fallacies - it will make you more resistant to commercial advertisements, political ads and religious hucksters.
And, I'm afraid that Anna unfortunately does not know what she's talking about. Still, that never stops any of us - it's everyone's God-given right to spout the most outrageous nonsense about anything and everything - it's your job as the asker to sort out the accurate from the wild-eyed insane answers...

Answer 8

we did!!

give me one decent piece of proof that we didn't!!

because we take a different branch from the ape, we are finished evolving from them, we are a new species, and if there was a human that developed from an ape, it would take so many thousnads of years, no one person would be alive to notice it, its not like a human pops out of the ape!

Answer 9

And here we see yet ANOTHER question that is borne out of sheer ignorance.
At NO time have scientists EVER said that man descended from apes. EVER.
The FACT is we are primates ourselves. We share a common ancestor with higher and lower order primates. Not only that, we share 98.985% of our DNA with the Common Chimpanzee. Gee I wonder why?

Anna is yet another one of those "cut and paste" answerers. And has been slapped around sufficiently that I don't have to answer.
Which is good because quite frankly, it gives me a headache just trying to think down to her level.

Answer 10

Apes would only evolve into humans now if there was a niche for that new species - there isn't because we are already here, filling that niche.

Answer 11

if there was a colony of birds, all the same species and some had slightly longer beaks than others.
And a drought occurred and there food staple disapeared.
But.. there was a flower they could eat nectar from.
But... only the birds with long beaks could eat from them what would happen to the birds with short beaks?
they would perish. thus only long beaked birds would have survived.

Now these little twists and turns over the hundreds of thousands of years have influenced the characteristic of every living thing on this planet.
Only two kinds of people cant see this fact.

Those who lack intellegence
and true believers