what is the theroy of evolution?

Question

Im supposed to write a paper explaining the theroy of evolution...but i just don't get it, and everyting i read on it is complicated.

Answer 1

Hmm... part of the reason why evolution seems complicated is because a really accurate version of it IS complicated. But if you like, I can try and sketch a sort-of cartoon version of it. Then you might be able to fit finer details in and see the picture better!

Evolution all starts with variation. Maybe it's obvious, but people are different from each other. Dogs are different from other dogs. And pretty much every species we know of has a lot of different individuals. It is those DIFFERENCES that give evolution the room to work. From what we understand about genetics more differences appear all the time too, as random mutations cause new traits to appear.

If you think about random mutations, you can't help but think that most of them are bad. After all, if you start changing random letters in books, you usually get garbage instead of Shakespeare. So why isn't there a log of biological garbage lying around?

That's the second very important part of evolution: natural selection. If you bought a book from the store and a bunch of the pages were screwed up, you'd probably throw it away. Nature does the same thing... just 'naturally'.

More than half of all embryoes that miscarry have genetic abnormalities. They are mutants that were too damaged to survive even in the womb. But some mutants make it further. If you can't run fast enough to escape a tiger, or if you're immune system is too weak to fight off a disease, then you'll be just as dead.

Still, some changes never make a massive difference. If you have no resistance to smallpox, it doesn't affect your health unless you're INFECTED with smallpox. And some things which are bad in one situation are good in another - tall people have a harder time tying their shoes but an easier time getting things off the top shelf. These things are passed on, and if they end up being more advantageous to future people they may even become commonplace.

In the end, most creatures end up being suited (over hundreds, if not thousands, of generations) to the place where they live. Birds the need to crack hard nuts develop strong, shallow beaks to apply pressure like a vice. Those that pluck small seeds from narrow enclosure develop long, thin beaks like pliers. It is an advantage for them to look like that, so they live better as long as they do. Given enough time, freak individuals may form new populations and even new species if they can find new ways to live.

So it goes. Hope that helps!

Answer 2

Here's a basic example of evolution that might help you:

Some bacteria cause infections that can kill people. People invented penicillin to kill the bacteria. At first, the penicillin killed almost all of the bacteria and it was like a miracle drug with many, many people surviving infections they would previously have died from.

But, notice, penicillin killed "almost all of the bacteria". This is critical. Those surviving bacteria (survival of the fittest) reproduced and the resulting "offspring" were also resistant to penicillin. Not only were these bacteria able to survive penicillin treatment, but they had a population explosion because all of those bacteria that were still susceptible to penicillin were killed off.

People invented stronger antibiotics. Bacteria evolved to resist. On and on it goes. Now we worry about super microbes (bacteria) that none of our antibiotics can kill.

Bacteria are a good example because they can produce new generations in 30 minutes or so. Larger organisms need much more time to produce new generations and thus, their evolution is much slower and harder to see.

Answer 3

Survival of the fittest. Random differences appear in a population. Most are harmful, and result in death. Some make no difference. Some give a survival advantage to the plant or animal that has this change (mutation), and the offspring of this species does better than the rest, outliving them and taking over the territory.
That is evolving. Darwin's Theory.

Answer 4

So you come in to Answers to see if it (evolution) could, by some miracle, become less complicated.

Talk to your teacher. Read a book. Get a tutor in biology. Open your mind. Let the knowledge penetrate the barrier you have put up.

Answer 5

Evolution is the gradual change of species from one to another type. The ones with better traits pass on those traits more rapidly, making them dominat. Like the way a giraffe's neck grew longer through time (thousands of years), the ones with longer necks could reach more food and passed their genes on more rapidly. ***

Answer 6

well start with charlas darwin read books i'm him and look up becoming human and neanderthals and and more questions email me at [e-mail]

Answer 7

This explanation should make it easier to understand:

http://www.newadvent.org/cathen/05655a.htm