Extinction vortex

Definition

An extinction vortex is a downward spiral in which small populations experience a decline in genetic diversity, leading to increased vulnerability to environmental changes and ultimately resulting in extinction. This process is driven by factors such as inbreeding, habitat loss, and demographic fluctuations, creating a feedback loop that exacerbates the decline of these populations. Understanding this concept is crucial for conservation efforts aimed at preserving species facing the threat of extinction.

5 Must Know Facts For Your Next Test

1. Small populations are particularly susceptible to extinction vortices due to their limited genetic diversity, making them less adaptable to environmental changes.
2. Inbreeding can result in increased homozygosity, which may cause the expression of deleterious traits that negatively impact survival and reproduction.
3. Habitat fragmentation exacerbates the extinction vortex by isolating populations, reducing gene flow and making it more difficult for individuals to find mates.
4. Demographic stochasticity, or random fluctuations in population numbers, can lead to larger impacts on small populations, increasing the likelihood of entering an extinction vortex.
5. Conservation strategies, such as habitat restoration and creating wildlife corridors, aim to counteract the effects of extinction vortices by promoting genetic exchange and increasing population sizes.

Review Questions

• How does genetic diversity play a role in preventing the extinction vortex in vulnerable species?
  • Genetic diversity is essential for the adaptability and resilience of populations facing environmental changes. When populations maintain high levels of genetic diversity, they are more likely to possess a range of traits that enable them to survive various challenges. Conversely, low genetic diversity increases susceptibility to diseases, environmental stressors, and inbreeding depression, which can trigger the extinction vortex. Therefore, promoting genetic diversity is a critical strategy in conservation efforts.
• Discuss the impact of habitat fragmentation on the likelihood of species experiencing an extinction vortex.
  • Habitat fragmentation can significantly increase the risk of species entering an extinction vortex by isolating small populations and limiting gene flow between them. As populations become more isolated, they may suffer from reduced genetic diversity due to inbreeding, which makes them less resilient to changes in their environment. Additionally, fragmented habitats can hinder individuals' ability to migrate and find mates, further exacerbating population decline. Thus, habitat connectivity is vital for maintaining viable populations.
• Evaluate potential conservation strategies that could be implemented to mitigate the effects of extinction vortices in endangered species.
  • To mitigate the effects of extinction vortices in endangered species, conservation strategies such as habitat restoration, creating wildlife corridors, and implementing breeding programs can be effective. Restoring habitats increases available resources and space for populations to grow while wildlife corridors allow for gene flow between isolated groups. Additionally, breeding programs can introduce genetic variation into small populations through carefully managed mating practices. By addressing both habitat quality and genetic health, these strategies collectively enhance population resilience against the pressures leading to an extinction vortex.

Related terms

Genetic Drift: A random process that can lead to changes in allele frequencies in small populations, which may contribute to the loss of genetic diversity.

Inbreeding Depression: The reduced biological fitness of a population due to mating between closely related individuals, which can increase the prevalence of harmful genetic traits.

Population Bottleneck: A sharp reduction in population size due to environmental events or human activities, leading to a loss of genetic diversity and an increased risk of extinction.