Genetic mutation question

[Northern]

Hi.
I'd like to ask a question about evolution and genetic mutation.

How exactly do genetic mutations happen?
We all know that for example, when a creature lives in a specific area, it'll overtime become more adapted to it. Like, if it's a desert, the creature will probably develop ways to conserve water and extract it in unusual ways etc.

The question is, how does the creature know which train to develop? Does the organism receive some kind of signaling that it needs to go in a certain evolutionary direction, or genetic mutations are completely random and it's just that those that accidentally turned out more successful get to live on?

Thanks.




heh neat.

[kevinchannon]

Originally Posted by Northern

The question is, how does the creature know which train to develop? Does the organism receive some kind of signaling that it needs to go in a certain evolutionary direction, or genetic mutations are completely random and it's just that those that accidentally turned out more successful get to live on?

It's the last one. There's a lot of subtlety to it though. I would recommend reading something like Richard Dawkins' "Blind Watchmaker" (I feel that in recommending Dawkins, I don't want to come across as some kind of zealot, I'm not, but his earlier books are a bit more toned down and very well written). You can probably get in on Amazon for the price of a cup of coffee.

The main point is that there's no pre-planned direction to evolution: mutations happen randomly during reproduction, changes beneficial to the organism reproducing survive in the population and ones that are detrimental to reproduction do not. That's basically it.

Seeing why a particular change might be beneficial to an organisms chances of reproducing can be more difficult to explain, such as the commonly cited "peacock's tail". Another caveat is that, given an example of an animal that displays a particular feature, you cannot usually work backwards through all the small steps that evolution took to get to the feature (without doing looking at fossils, or close living species, to find examples that match in every way except for the feature in question). These two things are the reason that people can get away with saying things like "That feature is useless, it doesn't help the survival of this animal at all. Therefore I have disproved evolution". Or, "This feature is too complex to have arisen without planning.

Hope that helps. (remember to buy the book, or a similar one, it will help a lot!)

[Warthaug]

kevinchannon gave a great answer. To add to his answer:

Every person/organism has dozen of new mutations not found in either parent. As a human, you have 200+ mutations not found in either your mom or dad. Those mutations are randomly scattered throughout your genome.

Evolution acts on those mutations. Exactly how is a complex question, and I would direct you to the same sources recommended by kevinchannon. The short version is that some of those mutations will give a slight benefit for the environment the organism is living in. Individuals with those beneficial mutations will produce more offspring, who also carry the mutation. Over time numerous beneficial mutations will build up in the population, leading to adaptation to the environment.

Bryan

[janet986w]

Hello !
I am also a new member. Would a newcomer be warmly welcome here? Good day you guy !

[luisillo]

Originally Posted by Northern

We all know that for example, when a creature lives in a specific area, it'll overtime become more adapted to it. Like, if it's a desert, the creature will probably develop ways to conserve water and extract it in unusual ways etc.

That's not a very good example, and that is the reason many people doesn't really understand evolution. Is as Warthaug and kevinchannon said: evolution is a relatively slow process and it can't be observed in individuals but in populations, since those slight changes in the individuals can't be considered fit until many or all of the individuals of a population have that change and are able to inherit it to their offspring.

Evolution can be seen relatively quickly. The better models to observe evolution in a quick way are bacteria and viruses.

[luisillo]

Originally Posted by janet986w

Hello !
I am also a new member. Would a newcomer be warmly welcome here? Good day you guy !