Why are the gene pools of small populations reduced compared to those of larger populations? (1 point)
• bottleneck events
• inbreeding
• lack of suitable mates
• lack of advantageous traits
All of the options mentioned contribute to the reduction of gene pools in small populations compared to larger populations.
1. Bottleneck events: A bottleneck event occurs when the size of a population drastically decreases, usually due to a natural disaster, diseases, or human activities. This sudden reduction in population size leads to a loss of genetic diversity because only a small subset of individuals survive, and their limited genetic variation becomes the basis for the future population. This reduced genetic diversity can have long-term consequences, as the gene pool is smaller and may not contain all the variations necessary for adaptation to changing environments.
2. Inbreeding: In small populations, individuals are more likely to mate with closely related individuals due to limited options for mate selection. Inbreeding reduces genetic diversity by increasing the probability of inheriting identical copies of genes from the same ancestor. This can lead to a higher frequency of deleterious genetic traits, as harmful recessive alleles become more likely to be expressed in offspring. Inbreeding depression can result in reduced fertility, lower viability, and increased susceptibility to diseases.
3. Lack of suitable mates: In small populations, there may be a limited number of potential mates available. This scarcity of suitable mates reduces the opportunity for genetic recombination and the introduction of new genetic variations into the population. Consequently, the gene pool remains restricted, restricting the potential for adaptation.
4. Lack of advantageous traits: Compared to larger populations, small populations have a reduced number of individuals, limiting the variation of advantageous traits. Advantageous traits are beneficial adaptations that enhance survival and reproductive success. In small populations, the frequency of advantageous traits is lower, making it more challenging for the population to adapt to new or changing environments.
Overall, the combination of bottleneck events, inbreeding, lack of suitable mates, and lack of advantageous traits leads to a reduction in the gene pool of small populations compared to larger populations. This reduction in genetic diversity can have detrimental effects on the long-term survival and adaptability of the population.