Answer:
I would recommend reading the descriptions and then reading the passage/story if you have not done that yet.
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in heritable traits of a population over time. The term "natural selection" was popularised by Charles Darwin who compared it with artificial selection, now more commonly referred to as selective breeding.
A(n) ___ is a group of terrestrial communities that covers a large area and is characterized by certain soil and ____ conditions and particular types of plants and animals
The scrotum reacts to temperature. When it is cold, the scrotum shrinks, pulling the testes against the body to keep them warm. When it is hot, the scrotum relaxes, lowering the testes away from the body. This contractile ability of the scrotum can either raise or lower the temperature of the testes by a few degrees, ensuring that the optimum temperature for sperm production is maintained.
The species of plankton found in sediments and their isotope ratios can show the temperature of the overlying waters when the sediments were deposited.
