When does Evolution occur in a population?

Answer 1

Evolution occurs at a constant rate from one generation to the next due to small genetic variations cause by mutation. This is known as the molecular clock. Eventually, one species will become many because these small genetic variations allows organisms with the same mutation to live in a slightly different environment. The finches of the Galapagos Islands is a good example of this type of evolutionary event. However, there time in Earth history where evolution seems to have occurred much faster. These leaps in evolution occurred because of changes in Earth climate. During these changes in climate, only the organisms with genes that allowed them to live in the new environments created by these climate changes survived. The others died off. Here is an example to this type of evolutionary event. Say there is a field of corn and in the field of corn there are a few plants that have a mutation that allows them to live with less water. While the rain fall is good this doesn't give those plants any better odds of survival than the others. However, in this example a period of low rain falls occurs causing a drought. The plants with the mutation do just grow up and create seeds just fine. The other corn plants die without create seeds.

Answer 2

Evolution is always occuring, it doesn't just happen.

However, in humans, it is unlikely to happen, as too few people die for humans to be prone to natural selection.

What happens, is that certain members of a gene pool will be unable to live in it's environment. Then, they die, and only the individuals fit for the environment mate. This means that only the better survival traits in a species are passed onto the young. These traits come from mutation, and mutation is what makes a gene pool able to have variety. Other ways gene pools get variety is through interbreeding, Immigration/emigration. The best parts of this variety survive, whereas the lesser traits die. That's why there are still monkeys in jungles, because their traits suit the jungle, whereas our traits suit flatland. Now, our traits suit the environment we create. Because we create our environment, it is less likely for humans to die.

However, this works slowly, over many generations. Humans no longer need to fit our environment, however, because less people die of obesity, and mutations in human genes that can benefit us are few and far between. Humans don't often die just because of the environment, so evolution is unlikely to happen, in the near future, anyway.

Answer 3

Evolution is a continuous process. There are no set boundaries between one species and another: the term species itself is merely a label we attach to a group of organisms bearing resemblance. In reality nature is not so well-defined. There are also no set rates at which evolution occurs. Rates of morphological, behavioural and even genetic divergence may vary wildly, depending on the circumstances. So there isn't really a single answer to this question.

Answer 4

I don't know the actual number but mutations happen constantly, even right now.

Answer 5

When its genetic makeup changes over time.

Answer 6

it changes with every addition

Answer 7

10

Answer 8

6