Modern humans do not need wisdom teeth. Some people never have them, and other people need to get them removed. What does the existence of unused structures, such as wisdom teeth, suggest about the ancestry of
humans?
A. Humans in the 18th century used their wisdom teeth to chew raw
plant material.
B. Humans evolved from chimpanzees, who use their wisdom teeth
to digest their diet.
C. Humans evolved from an earlier species that had wisdom teeth,
which were important to the survival of the earlier species.
D. Wisdom teeth may help humans survive as conditions on Earth
change.

Microorganisms aren’t all decomposers; in fact, many act as producers or primary consumers in an ecosystem. how do microorganisms that act as producers benefit the rest of an ecosystem in terms of energy transfer? what about microorganisms that act as primary consumers?

Based on the law of dominance, we would expect percent of the offspring from this cross to have large teeth.

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.