Arrange the processes driving an extinction vortex in a small population:
A. Smaller population B. Inbreeding and genetic drift C. Loss of genetic variability D. Lower individual fitness and population adaptability E. Lower reproduction and higher mortality
Choose the most appropriate answer from the options given below:

Correct option is B

The extinction vortex in a small population is driven by interrelated genetic, ecological, and demographic processes. The sequence in the extinction vortex starts with inbreeding and genetic drift (B), which cause a loss of genetic variability (C). This leads to lower individual fitness and adaptability (D), eventually resulting in lower reproduction and higher mortality (E), which further reduces population size (A). The smaller population size intensifies the effects of inbreeding and drift, perpetuating the cycle.
Explanation of the Sequence: 1. B. Inbreeding and genetic drift: Small populations experience random genetic drift and inbreeding, reducing genetic diversity and increasing harmful allele frequencies.
2. C. Loss of genetic variability: Genetic drift and inbreeding erode genetic diversity, limiting the population's ability to adapt to environmental changes.
3. D. Lower individual fitness and adaptability: Reduced genetic variability causes inbreeding depression, lowering reproductive success and survival rates.
4. E. Lower reproduction and higher mortality: Inbreeding depression reduces reproduction, while low adaptability increases mortality, further reducing population size.
5. A. Smaller population: The decline in population size exacerbates genetic and demographic pressures, perpetuating the vortex.
Key Points: 1. The extinction vortex creates a self-reinforcing cycle, driving small populations toward extinction.
2. Inbreeding and drift reduce genetic diversity, while demographic stochasticity increases extinction risk.
3. Conservation efforts aim to increase population size and genetic variability to break the vortex.
Information Booster: 1. Inbreeding Depression: Causes reduced fertility, survival, and resistance to diseases in small populations.
2. Genetic Drift: Random loss of alleles in small populations limits genetic diversity.
3. Loss of Variability: Reduces adaptability, increasing extinction risk under changing environmental conditions.
4. Allee Effect: A phenomenon where smaller populations face difficulty reproducing or functioning, accelerating extinction.
5. Conservation Measures: Include maintaining genetic diversity, habitat restoration, and boosting population size to mitigate the vortex.
Additional Knowledge: · Inbreeding and Genetic Drift (B): Small populations face disproportionate effects of genetic drift and inbreeding, causing harmful mutations and loss of fitness.
· Loss of Genetic Variability (C): Genetic diversity is crucial for a population’s resilience to environmental changes. Its loss makes the population less adaptable and more vulnerable to diseases.
· Lower Fitness and Adaptability (D): Inbreeding depression and loss of variability cause a decline in population fitness, leading to higher susceptibility to threats.
· Lower Reproduction and Higher Mortality (E): Reduced fitness translates into decreased reproduction and increased mortality, accelerating population decline.
· Smaller Population (A): This reduction intensifies inbreeding, genetic drift, and demographic stochasticity, creating a feedback loop.