Question

How does the environment influence natural selection?

Answer 1

Survival may be a mechanism of evolution. Organisms that are more adapted to their environment are more likely to survive and expire the genes that aided their success. This process causes species to vary and diverge over time.

Complete answer:
In a population, the survival will favour the individuals with the upper fitness (In other words : those which have the simplest chances to survive and reproduce) during a given environment.
Natural selection becomes on the phenotypic level. Also, remember that the phenotype is the results of the interaction between genotype and environment. It means , for various environments, one gene can give different trait values at the phenotypic level.
Variation exists within all populations of organisms. This happens partly because random mutations arise within the genome of a private organism, and their 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 biology within the cell, other cells, other individuals, populations, species, also because of the abiotic environment.
Because individuals with certain variants of the trait tend to survive and reproduce quite well with other less successful variants, the population evolves. Other factors affecting reproductive success include sexual selection (now often included in natural selection) and fecundity selection.

Note:
Survival is the differential survival and reproduction of people thanks to differences in phenotype. It's a key mechanism of evolution, the change within the heritable traits characteristic of a population over generations. Darwin popularised the term "natural selection", contrasting it with artificial selection, which in his view is intentional, whereas survival isn't.