How does genetic variation allow humans to survive?

Genetic variation is an important force in evolution as it allows natural selection to increase or decrease frequency of alleles already in the population. Genetic variation is advantageous to a population because it enables some individuals to adapt to the environment while maintaining the survival of the population.

Why do rare genetic diseases continue to occur in the human population?

Diseases are thought to persist in human populations primarily because of a balance between mutation, genetic drift, and natural selection, with alleles that contribute to disease introduced by mutation, governed in part by random genetic drift, but eventually eliminated from the population by purifying selection 5, 7.

Does natural selection deal with diseases?

From an evolutionary perspective, infectious diseases have probably been the primary agent of natural selection over the past 5000 years, eliminating human hosts who were more susceptible to disease and sparing those who were more resistant.

How does natural selection affect genetic diversity?

Natural selection can decrease the genetic variation in populations of organisms by selecting for or against a specific gene or gene combination (leading to directional selection).

Why is genetic diversity essential for the survival of a species?

Genetic diversity serves as a way for populations to adapt to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment. Those individuals are more likely to survive to produce offspring bearing that allele.

Why genetic diversity is important for survival?

Genetic diversity is important because it helps maintain the health of a population, by including alleles that may be valuable in resisting diseases, pests and other stresses. If the environment changes, a population that has a higher variability of alleles will be better able to evolve to adapt to the new environment.

Why do genetic disorders occur?

Genetic disorders can be caused by a mutation in one gene (monogenic disorder), by mutations in multiple genes (multifactorial inheritance disorder), by a combination of gene mutations and environmental factors, or by damage to chromosomes (changes in the number or structure of entire chromosomes, the structures that …

How does natural selection negatively affect humans?

In general, negative selection eliminates from the population very harmful changes to proteins that kill or stop reproduction. The authors also found a correlation between genes predicted to be under negative selection and genes implicated in certain hereditary diseases.