Question

.	A colony of snails are living on a forest tree near a river. Other colonies are on nearby trees. When the river floods, a tree is swept away, with the snails riding along. When the floodwaters subside, the tree and snails have landed in a new habitat, where this type of snail did not previously live. The snails reproduce, and establish a successful population in the new habitat. Assuming no more snails from the original population arrive, over a long period of time what is the most likely outcome for the new population of snails? speciation, resulting in the formation of a new species of snail in the new region.
	d	cnothing, without some pressure forcing them apart, the new population and original populations will remain populations of the same species.
	c.	d.extinction, if the snail could survive in the new habiat, there would already have been a population of snails there.
	d. Any normal human being would recognize this as the back of a pantyhose box. I, however, being an evolutionary biologist, immediately thought it looked like a geographic map showing distributions of 5 species of snails. The species are: S, M, L, XL, and XXL.

If these were species, what word describes the level of geographic isolation of S and XXL_________________? $xid-5132323_1$ a. allopatric b. sympatric c. vicariant

invasion, the new population will expand, taking over other snails' habitat.

Answer 1

The answer is E.

Species evolve only under pressure. Since the snails have reproduced and sucessfully built a colony in the new place, it means that they have the needed genes to esablish a colony there. They do not need to evolve into another species to face the challenges of the new place.

But usually species which are introduced into new places, quickly grow and take over the habitat of the existing species. Since they are exposed to new food and resources, they multiply quickly and outnumber the existing population