Final answer:
The question delves into population genetics in Biology, examining how environmental changes and natural selection influence allele frequencies in a wild insect population. Factors such as effects of DDT, environmental shifts, and population size are crucial in shaping genetic variation and understanding evolutionary dynamics.
Step-by-step explanation:
The subject of this question pertains to population genetics within the field of Biology, focusing on how environmental factors and natural selection can influence allele frequencies in a population. When discussing a wild insect population, key factors that can change allele frequencies include:
- Effects of DDT usage, which not only killed a large proportion of insect population but may have also induced mutations, leading to DDT-resistant alleles in the surviving population. This is a case of natural selection where surviving insects with a certain allele (DDT resistance) have a higher fitness and are more likely to pass on their genes.
- Sudden environmental changes, like a rise in temperature leading to fruit scarcity, can affect allele frequencies by either favoring individuals capable of surviving with less food or those that can thrive in higher temperatures. These shifts in environment can lead to a change in allele frequency due to differential survival and reproduction.
- Population size and density, which have significant effects on genetics. Smaller populations may be more susceptible to genetic drift and lose genetic diversity quicker, while in larger populations, selection pressures may more strongly influence allele frequencies.
As a result, an allele that shortens developmental time could increase in frequency if it leads to a higher survival rate under changing environmental conditions. This is a classic example of how natural selection can operate to shift allele frequencies, potentially having a significant impact in populations of organisms like insects.