Can you explain Evolution better?

Question

Hello,

I am studying evolution right now, and wondering a little about it.

Did we evolve from other animals, or how did it work? And how long did it take humans to get here?

Can someone just give me a basic summary of how this all happened? I am confused about how it works!

Answer 1

Without specific questions, it's hard to explain one of the most important theories in all of biology with a short answer ... but here you go:

First, the word "evolution" just means "slow change over generations." (There is a more precise, but still short, definition involving terms like "allele frequencies" ... but it basically just boils down to "change over generations.")

We can see that this process happens. Every time some cocker spaniel breeder picks the best puppies from each litter, and breeds the winners from dog shows to other winners ... over several generations ... that breeder is taking advantage of evolution ... slow change over generations.

The first question is how this process occurs in the wild. This is where Darwin's theory comes in. Basically, in any species, some individuals are born with some genetics that makes it better at surviving than other members of the same species. So those individuals go on to have more babies, and as a result pass on those very genetics that gave them an advantage ... onto their offspring. So over time, the species changes ... change over generations = evolution.

That process is like a non-stop engine. As long as things are struggling for survival, they are constantly changing genetically. Keep that non-stop engine (evolution) in mind as you read the following.

The second question is how new species are born. Basically, species *branch*. If two populations of a species get isolated, that non-stop engine I'm talking about causes their genetics to become more and more different. With enough time, the genetics are *so* different, that they are unable to breed with each other. That is the definition of "species" (unable to breed with each other). So that one species has become two species.

At first those two species are very much alike (think horses and donkeys). But once they are unable to interbreed, the will never share genetics again, and so they will evolve *completely* separately. Getting more and more different from each other. More time, more difference.

And each branch may branch again ... and again ... and so on. Some of those branches will go extinct. But those that did not go extinct are alive today. And that is all the species on the planet.

Our (human) branch seems to be related (according to genetics) to a common ancestor with the chimp branch that lived about 3-5 million years ago ... and then with an ancestor much further back with the other ape branches ... and another ancestor (even further back) shared with the monkey branches ... and so on all the way back in time to the first one-celled organisms in the early oceans of the earth.

That's how it works.

But that was just an explanation. I did not go into all the evidence for this ... as this would be another post as long as this one. (I.e., there's a *lot* of evidence.)

But I'll just summarize and say that the evidence of common ancestry between modern species is there in the genetics themselves (we can see in the DNA exactly how long ago two branches separated), in fossils of animals that lived long ago (most of them extinct), in the structures of modern animals, plants, etc., in the way embryos develop, in the locations of animals and their fossils on the earth (for example, that all kangaroos and their fossils, occur *only* in Austalia), in the way viruses become immune to diseases, insects become resistent to pesticides. Etc. etc.

But I highly recommend keeping the two questions of explanation and evidence, separate.

*Understand* evolution before you start examining the tons of evidence for it and deciding whether you believe it. Too many people make up their minds on the evidence based on a really shallow understanding of what the theory says.

Feel free to email me with questions (a lot of people do). And I know a lot of other people on Y!A feel the same.

Good luck!

Answer 2

A couple of excellent sites to help you:
Start with the FAQ at Talk Origins
http://www.talkorigins.org
The section "Understanding Evolution" at No Answers in Genesis should help you as well
http://www.noanswersingenesis.org.au/

Both these sites have a wealth of information about evolution with as much detail and references as you could hope for.

Answer 3

The theory of evoluation has many assumptions that have never been proven.

The video "Where Does The Evidence Lead?" examines Darwinian evolution and presents a powerful challenge to its validity.

If Darwin knew about the complexity of the living cell, he would not have come up with this theory.