Final answer:
The patterns of genetic differences that can occur at a particular chromosome location are called polymorphisms. They are crucial for the study of genetic variation within populations and are key factors in allopatric speciation due to geographical separation and environmental differences.
Step-by-step explanation:
When different patterns of genetic differences occur at a particular location on a chromosome, they are referred to as polymorphisms. This concept is essential in the study of genetics, particularly when looking at the variation within a population's gene pool and how this variation can contribute to phenotypic variation. Polymorphisms arise due to mutations that lead to new alleles at a genetic locus, and these can accumulate over time especially when a population is geographically separated, resulting in a process known as allopatric speciation.
Geographical barriers limit gene flow between populations, allowing them to diverge genetically and even lead to the development of new species. The environmental conditions such as climate, predation, and resources differ in each location, thus natural selection tends to favor different adaptations in each population. Examples of polymorphisms that aid in genetic mapping include single nucleotide polymorphisms (SNPs), variable number tandem repeats (VNTRs), and restriction fragment length polymorphisms (RFLP).