Answer: The correct answer for the fill in the blank is B) Advantageous traits become more common in a population.
Theory of natural selection was given by Darwin. This is one of the mechanisms of evolution.
According to this theory, organisms that are better adapted to their environmental conditions survive and increase their population by reproduction. So they pass the advantageous trait to the next generation. In other words, it reflects the survival of the fittest.
Due to this, the advantageous trait becomes more common in the population.
Thus, the correct option is B)
The answer is D. In a
geological era, when the plants and animals
in the then environment die, they get buried
in sediments. These sediments are covered
by other sediments of another geological
time within which are the remains of dead species
of the then geological era. These sediments from different geological times have different properties hence
form visible strata that can be studied to identify the kind of environment in the then geological time. Their
fossils can also be studied to identify
the kind of species that roamed the earth during the time.
Trace fossils represent things that were alive, it could be footprints, or bones.
I think this option fits best:
"<span>Evidence that animals were at some time in the area."</span>
