Question about evolution and diversity?

Question

When non-living matter became living matter - what was the function(?) that led to the genetic diversity we see today? Was it solely mutations in the beginning?

I don't question that it happened - I am just having a hard time understanding how so much genetic diversity evolved out of such a small pool of genetic info (the single-celled organisms of the earliest days) to create all of the animals and such we have today.

Was evolution dependent on mutations until enough mutations occurred to allow certain things to be selected for and genetic variation entered the pool?

Thanks!

Answer 1

You've got it! It took MILLIONS of years.

Answer 2

It was largely based on mutations. DNA doesn't always copy itself perfectly, and from time to time it'll accidentally write a different code than the one that it was originally.

Those mutations then either helped or hindered the creature/plant. For instance, if it was an abnormal one that caused the thing to get cancer, then it would kill off the creature. But if it was a beneficial one, say it helped give a fish an extra fin for slightly faster swimming, it was a helpful one. Given enough time, it could evolve into an entirely different creature than the one that originally created it.

The mutations can also do other things. For instance, some fish gradually began to develop primitive legs and lungs, allowing them to stay out of the water more and more. Eventually they became amphibians, who still need to go back to water to lay eggs, but can survive on land for short periods of time.

Evolution is more about adapting to changes in nature, rather than an animal getting an extra claw or teeth. If those changes are beneficial, then they survive and produce offspring with those same characteristics. If it's not helpful, then they start to die out.

One reason why man's ancestors were able to succeed was because they had large enough brains to be able to adapt to the changes around them. For example, some apes learned that they could get nutrition from the bones of animals by cracking them open and eating the marrow, something that other animals were unable to do since they didn't know about it nor did they have the changes in their hands to be able to hold a rock to do that with. Eventually those apes would start getting smarter about getting food and survival techniques, such as learning how to create fire, which helped cook meat to kill off germs and parasites, not to mention make it easier to eat the meat.

Answer 3

Actually mutation most likely played a smaller role than most might imagine. The chances are that when the first RNA replicating organisms began it was not something that happened to just one molecule but rather that it began to be a common condition in the primal seas. There were likely vast areas where trillions of such molecules were encountering each other and variously inter-combining creating huge variations in the specifics of such reactions. These were the raw materials from which DNA replication formed the kinds of living things we are more familiar. The process by which cell walls were added may have been a long way after the beginning, the first organism ma not have been discretely contained - but rather more like a protein plaque such as bacteria form around them. The varied conditions of this environment, higher/lower PH in different areas, wetter or drier conditions in others, amount of flexibility in what kinds of substances could be metabolized by these earlier proto-organisms and competition for nutrient sources between different molecular configurations probably also helped to enable some variation in the ways that these began to involuntarily became selectively specific variations in order to fit the different environments.  

Answer 4

Evolution can't explain how life began in the first place.  But once life did begin, living things created opportunity for other living things.  Living things, plants and animals, are -food-!  So other creatures came about because of the opportunity to eat this food, or even to eat the waste products other life forms leave behind, or the dead bodies of lifeforms after they're finished.

This is what causes diversity!  Plants grow, able to synthesize their own food from sunlight and water and air. Animals come around to eat the plants. Other animals come to predate the plant-eating animals.  Insects come to eat the animals' p**p and clean up the animals' dead bodies.  Birds and reptiles come to eat the insects.  Each species provides opportunities for other species to develop.  In any natural environment this all reaches a balance.  Man tampers with the balance, and then finds it's all he can do to deal with the imbalance.