Evolution
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Firegarder Joining The Black Parade Age: 38 Gender: Female Posts: 233 | murder tramp;: Ok, I don't know if I will write this in a way that will make sense, but I will try! The environment does not have an affect on the actual chromosomes themselves. You get offspring that are different to parents by the male and female chromosomes being mixed together, also as eggs and sperm are created, chromosomes are capable of swapping little bits of themselves over to create changes. And don't forget the old random mutations! From this a completely new individual is created. The chromosomes in this individual determine their characteristics and therefore their survivability. So, if the environment is cold, and you inherit a hairless gene form your parents, you would not be able to survive as well/as long as an inidividual that has a hairy gene! That gene doesn't survive and get passed on then. I haven't exaplined this very well have I? |
Lovesick Melody. Bulletproof Heart Age: 83 Gender: Female Posts: 25760 | Females are certainly part of the evolutionary chain! I'll ignore environmental evolution and just look at the chemical process of reproduction. In the body cells, like skin and organs, cell division occurs. This is done by mitosis, where identical cells to the originial cell is produced. This is different than in the sex organs, like the ovary and testes, where meiosis takes place. Here is a diagram: See how in the second phase, some red has gone into the blue and some blue has gone onto the red chromosome. This is called recombination. This is a shuffling of the DNA that is entirely normal and natural, which can create new traits in the offspring. This goes along with other processes that create genetic diversity in offspring, such as independent assortment (look at the gametes, or last cells in the diagram, and you can see the variation in all off the potential offspring), Segregation and even random fusion of these gametes through mate choice. This is all with the normal mutations in the DNA that happen during cell replication. So I can say with confidence that genetic changes do take place within the ovaries or testes, and therefore women and men alone without environmental pressures create genetic change within their sex cells. some site: You're right, they don't make an 'intelligent' change, it's all chance. Say you have a 2 red butterflies that create offspring, one that has the normal red offspring, and one that has a mutated green offspring. The green offspring is more likely to survive in the wilderness and therefore carry pass of the green trait. Red butterflies are less likely to pass on their trait as they are more likely to get spotted and eaten. But as you say, this seems like an 'intelligent' change and completely likely. However it can work the other way around. Say a green butterfly has mutated red offspring. They are more likely to get eaten and therefore they don't pass on their genes. Because this trait didn't give them an advantage, they were killed and therefore it isn't inherited. The red trait dies because it's not the best suited trait for the environment. That's the whole point about 'survival of the fittest', some mutations give the organism a [i[disadvantage[/i] and they are more likely to die and not pass it on. Therefore only the organisms best suited to their environment pass on their genes. Remeber evolution doesn't happen in 10, 100 or 1000 years. It happens over millions of years! |
callmemrx Killjoy Age: - Gender: - Posts: 8 | Evolution is now indisputable scientific fact, the question is not whether or not evolution occurs or not, the 'theory' is in which way does it occur. Personally, I'm going to stick with natural selection, as the facts it presents seem the most probable. |
neradalovesMCR Killjoy Age: - Gender: Female Posts: 2 | i dont leave in evolution.... i dont worry about it. |
doctor. In The Murder Scene Age: 30 Gender: Female Posts: 23302 | neradalovesMCR:The discussion forum is a place for just that; discussion. If you do not have anything to post that would contribute to the discussion, please don't post at all. |
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