The correct answer is - underwater mountain ranges.
The mid-ocean ridges are actually underwater mountain ranges, which usually are very long, in fact the longest mountain range on Earth is created on the divergent boundary between the Eurasian and North American tectonic plates and between the African and South American tectonic plates. At the divergent tectonic boundaries we have the creation of new crust which rises from the mantle and fills in the gap between the tectonic plates. Because of the big amount of magma and high pressure, very big and long underwater mountain ranges are formed.
Answer:
b. the bottleneck effect.
Explanation:
The bottleneck effect occurs when a population's size is reduced for at least one generation. This will result in a very reduced genetic variation, which can lead to further adaptation problems.
The Founder effect has its similarities (in terms of the resulting reduced genetic pool) with the bottleneck effect, BUT it occurs when a new colony is started by a few members of the original population.
The Hardy-Weinberg equilibrium is a principle in population genetics that states that the genetic variation in a population will remain constant from one generation to the next IF certain conditions are present (no migration, aleatory mating, among others), so this is not the answer.
Genetic drift (refers to the change in the frequency of an existing gene variant in a population due to random sampling of organisms, so it is not the answer.
Answer:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
