Read the text and answer the questions.

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. Charles Darwin popularised the term "natural selection", and compared it with artificial selection.

Variation exists within all populations of organisms. This occurs partly because random mutations arise in the genome of an individual organism, and offspring can inherit such mutations. Throughout the lives of the individuals, their genomes interact with their environments to cause variations in traits. The environment of a genome includes the molecular biology in the cell, other cells, other individuals, populations, species, as well as the abiotic environment. Individuals with certain variants of the trait may survive and reproduce more than individuals with other, less successful, variants; therefore, the population evolves. Factors that affect reproductive success are also important, including sexual selection (now often included in natural selection) and fecundity selection.

Natural selection acts on the phenotype, or the observable characteristics of an organism, but the genetic (heritable) basis of any phenotype that gives a reproductive advantage may become more common in a population. Over time, this process can result in populations that specialise for particular ecological niches (microevolution) and may eventually result in speciation (the emergence of new species, macroevolution). In other words, natural selection is a key process in the evolution of a population. Natural selection can be contrasted with artificial selection, in which humans intentionally choose specific traits, whereas in natural selection there is no intentional choice.

1. What is key to evolution?
2. What is natural selection?
3. Who made that wording popular?
4. What did he compare it to?
5. Is variation common in organisms?
6. Why does this happen?
7. What happens to the offspring?
8. Do genomes interact often?
9. What type of biology is involved?
10. Do cells play a factor?
11. In what type of environments?
12. Is reproductive success or failure important, which?
13. Is selection important too?

Numbered answers:
1. Natural selection
2. differential survival due to differences in phenotype
3. Charles Darwin
4. artificial selection
5. yes
6. because random mutations arise
7. they can inherit mutations.
8. yes
9. molecular biology
10. yes
11. in biotic as well as the abiotic environment
12. reproductive success is important
13. yes