Question

can ALL three questions be answered please.

1. is it possible for natural  selection to occur but a population to not evolve. Briefly describe a situation that could allow that to happen.

2. Each year, all the ginkgo trees in an area drop their leaves at nearly the same time, a phenomenon called "The Night of the Ginkgo". Give a plausible (not necessarily correct!), good scientific hypothesis for this observation.

3. Many terrestrial mammals weigh much less than a pound, yet the smallest fully marine mammal is the sea otter, which weighs over 30 lbs. as an adult. How might the surface area: volume ratio contribute to the large size of marine mammals?

a. Animals with high SA:V ratios retain heat more efficiently.

b. Animals with low SA:V ratio retain heat more efficiently.

c. Animals with high SA:V ratios generate more heat via higher metabolisms.

d. Animals with low SA:V ratio are able to take more prey.

Answer 1

Solution:

1) Yes, it is possible for to have natural selection taken place without evolution of the whole population. This explanation is just hidden in the definition of natural selection itself. The natural selection takes place in only certain individuals and not the whole population. These individuals are born with some speacial characteristics which deal with the unfit circumstances. Whole population except these certain individuals lack these characters and hence is vanished.

2) Ginkgo biloba is also known as maidenhair tree. Gingko leaves fall off the tree in a short period of time. The scientific reason behind this phenomena might be that they have been surviving from a long duration of time with no such differences in the characteristics. Falling of leaf occurs in a particular season. All the trees produce same amount of hormone which causes the falling of leaves. When this reaches to a peak, the leaves fall on one particular day.

3) The correct option is a. A high surface area to volume ratio is observed in marine animals as compared to the terrestrial animals. A high surface area allows the entering of significant quantity of raw materials into the volume. When the surface area to volume ratio is low, the enough raw materials are not stored and the metabolism is low. As the heat retained is more and is stored efficiently, the cell size and body size is bigger.