Final answer:
The two main problems with isolation and lack of gene flow are reduced genetic diversity, which can lead to increased inbreeding, and the potential for higher gene exchange leading to species extinction. This is due to the increased chance of maladaptive genes becoming more prevalent and the inability of populations to adapt to environmental changes. Statement A and D are correct.
Step-by-step explanation:
When considering the problems with the isolation and lack of gene flow due to housing development, the correct answer consists of two primary issues:
- Reduced genetic diversity and increased inbreeding
- Higher gene exchange and species extinction
Isolation can lead to significant genetic drift, where the frequency of rare alleles can increase over time. This reduced gene flow can culminate in populations becoming genetically distinct, leading to a rise in maladaptive gene variants. An example is the increased frequency of Tay-Sachs disease among isolated populations due to a lack of new genetic information entering the gene pool.
Similarly, populations subjected to habitat isolation evolve independently, which results in divergent adaptations. In a fragmented habitat, isolated species may eventually become extinct as their small population sizes make them more prone to environmental changes and reduce their ability to adapt. Additionally, the loss of wild species due to habitat disruption can diminish the overall genetic variation within a region, as gene flow from wild relatives into crop varieties brings valued characteristics to those crops.