key term - Genetic variation

Definition

Genetic variation refers to the differences in DNA sequences among individuals within a population. This variation is crucial for the process of evolution, as it provides the raw material upon which natural selection can act, allowing species to adapt to changing environments and survive over generations.

5 Must Know Facts For Your Next Test

1. Genetic variation is primarily generated through mutations, gene flow, and sexual reproduction, which reshuffles alleles in populations.
2. This variation is essential for the survival of species as it enables populations to adapt to environmental changes and resist diseases.
3. The measurement of genetic variation in a population can be indicative of its overall health and ability to adapt to future challenges.
4. Inbreeding can reduce genetic variation by increasing the likelihood of offspring inheriting the same alleles from both parents, which can lead to decreased fitness.
5. Conservation efforts often focus on maintaining genetic variation in endangered species to enhance their resilience against extinction.

Review Questions

• How does genetic variation contribute to the process of natural selection?
  • Genetic variation provides the diverse traits that are essential for natural selection to occur. When environmental changes happen, individuals with advantageous traits are more likely to survive and reproduce. This means that their genes will be passed on to the next generation, leading to an increase in those beneficial traits within the population. Without genetic variation, there would be no differences for natural selection to act upon, which would hinder adaptation.
• Evaluate the importance of maintaining genetic variation within a population and the consequences of reduced variation.
  • Maintaining genetic variation within a population is crucial for its long-term survival and adaptability. High levels of genetic diversity allow populations to respond effectively to environmental changes, diseases, and other pressures. Conversely, reduced genetic variation can lead to inbreeding depression, where populations become less fit and more susceptible to extinction due to a lack of adaptive traits.
• Discuss how different mechanisms such as mutation and gene flow influence genetic variation in populations over time.
  • Mutation introduces new genetic variations by altering DNA sequences, which can create new alleles that may be beneficial or neutral. Gene flow occurs when individuals migrate between populations, bringing new alleles into a gene pool and increasing overall genetic diversity. Together, these mechanisms ensure that populations remain adaptable over time by introducing new traits that can be subject to natural selection, thereby shaping the evolutionary trajectory of species.

Related terms

alleles: Different forms of a gene that can exist at a particular locus on a chromosome, contributing to genetic diversity.

mutation: A change in the DNA sequence that can introduce new genetic variations, which may be beneficial, neutral, or harmful.

natural selection: The process by which organisms better adapted to their environment tend to survive and reproduce more than those less adapted, leading to evolutionary changes.