Question

Discuss how the various “agents” of change can lead to a new species.

Answer 1

It sounds like you are in the same class I am in. SU online Biology? I need help on the same two questions. If you figure anything out will you help me and I will do the same?

Answer 2

Look in our text book under Mechanisms of Speciation, which is on page 274 if you have it downloaded on your computer. If not I'm not sure what page it is on if you are accessing it through our class room but it is in chapter 14. I think this is where the answers are. I hope this helps!

Answer 3

Because of reproductive isolation.

This refers to the fact that populations of a species sometimes get separated from each other so that they can no longer interbreed. For example, a river cutting through a valley, a change in climate that dries up the valley between mountain ranges, a drought that causes a major migration, an epidemic that kills off much of the population leaving small isolated populations.

If they are separated, and cannot exchange genes, then the changes in one population have no way to spread to other populations.

So the "agents of change" (like natural selection and genetic drift) will continue to operate in these separate populations, but will produce *different changes*. Different mutations will arise and spread in each population.

And so, over time, the populations will lose the *ability* to cross-breed, even if they come into contact again.

So what was once a single species, will now be two (or more) species.

That's called branching ... or more technically, 'speciation', and is a key part of evolution.