Read the statement.
A population of foxes only has one allele for a gene that codes for a necessary function in their heart. A new allele for the gene is present in a litter of foxes. Years later, the fox population still only has one allele for this gene.
Why is there still only a single allele for this trait?
Is it either on the X or Y chromosome?
The presence of only a single allele for a gene in a population can be explained by the principles of genetics and evolution. In this specific scenario, there are a few possible reasons why the fox population still only has one allele for the gene that codes for the necessary heart function.
1. Allele frequency: Initially, the new allele that appeared in a litter of foxes might have been present in very low numbers in the population. If the frequency of this new allele remains low throughout generations, it is less likely to become widespread in the population.
2. Selection pressure: The allele that codes for the necessary heart function might be advantageous or disadvantageous in terms of the fitness of the foxes. If having more than one allele for this gene does not offer any selective advantage, due to natural selection, genetic drift, or other factors, the new allele may not spread throughout the population.
3. Genetic drift: Genetic drift refers to random fluctuations in allele frequencies that can occur in small populations. If the population of foxes with the new allele is small, the random sampling of alleles during reproduction can result in the loss of the new allele, or it may fail to become established in the population due to chance alone.
It is important to note that this is a hypothetical scenario, and without further information, it is challenging to determine the exact reason why the fox population still possesses only one allele for this gene. More studies, including observing the reproductive success and survival advantage associated with the new allele, would be needed to fully understand the situation.