Loss of genetic diversity

Definition

Loss of genetic diversity refers to the reduction in the variety of genes within a population, leading to a decrease in the overall genetic variation. This phenomenon can have significant impacts on a population's ability to adapt to changing environments, resist diseases, and survive in the long term. A population with low genetic diversity is more susceptible to inbreeding, which can amplify negative traits and lead to inbreeding depression, while genetic rescue can help restore diversity and improve population resilience.

5 Must Know Facts For Your Next Test

1. Loss of genetic diversity can lead to decreased adaptability, making populations more vulnerable to environmental changes and diseases.
2. Inbreeding depression is a direct consequence of loss of genetic diversity, where closely related individuals produce offspring with lower survival rates and fertility.
3. Genetic rescue is often employed as a conservation strategy to counteract the effects of loss of genetic diversity by introducing new genes into a small or isolated population.
4. Small populations are particularly at risk for loss of genetic diversity due to factors like genetic drift and increased likelihood of inbreeding.
5. Maintaining genetic diversity is essential for the long-term survival of species, as it enhances resilience against disease outbreaks and environmental stresses.

Review Questions

• How does loss of genetic diversity influence the overall health and viability of a population?
  • Loss of genetic diversity negatively affects the health and viability of a population by reducing its ability to adapt to changing environmental conditions. When genetic variation is low, there is less potential for individuals within the population to possess traits that may confer advantages under new challenges, such as disease or climate change. This vulnerability can lead to decreased reproductive success and an increased likelihood of extinction over time.
• Discuss the relationship between inbreeding depression and loss of genetic diversity, including the potential consequences for endangered species.
  • Inbreeding depression arises from loss of genetic diversity as closely related individuals breed, resulting in offspring that may inherit harmful recessive traits. For endangered species, this can be particularly detrimental since their already low population numbers mean that many individuals share similar genetics. The consequences can include reduced fertility, lower survival rates, and an overall decline in population numbers, further pushing these species towards extinction.
• Evaluate the effectiveness of genetic rescue as a strategy to combat loss of genetic diversity, providing examples where it has succeeded or failed.
  • Genetic rescue can be an effective strategy to combat loss of genetic diversity by introducing new genetic material from outside populations, thus increasing variation and improving fitness. For example, the Florida panther was saved from inbreeding depression by introducing Texas cougars into their population, leading to healthier offspring. However, success is not guaranteed; if the introduced genes do not blend well with local adaptations or if the new population faces other threats like habitat loss, it may not achieve the desired outcome. Therefore, careful planning and consideration of ecological contexts are crucial for effective implementation.

Related terms

Inbreeding Depression: A reduction in fitness and health of a population due to breeding between closely related individuals, often resulting in increased prevalence of harmful genetic traits.

Genetic Rescue: The introduction of genetic material from outside populations into a declining population to increase genetic diversity and enhance its adaptive potential.

Population Bottleneck: An event that drastically reduces the size of a population, leading to a loss of genetic variation as only a few individuals contribute to future generations.