Final answer:
Methods for determining linkage groups and genetic maps in humans include linkage analysis, physical mapping techniques like cytogenetic, radiation hybrid, and sequence mapping, and insights from the Human Genome Project.
Step-by-step explanation:
Methods for determining the linkage group and genetic map in humans involve various techniques. One such method is linkage analysis, which estimates the recombination frequency between genes to ascertain if they are linked, indicating that they are located on the same chromosome and tend to be inherited together. If two genes show a high frequency of recombination, they are likely to be farther apart on the chromosome.
To construct a more complete picture of the genome, genetic linkage maps are often complemented by physical maps, which include cytogenetic mapping, radiation hybrid mapping, and sequence mapping. Cytogenetic mapping involves analyzing stained sections of chromosomes under a microscope to find the distance in base pairs between genetic markers. Radiation hybrid mapping utilizes radiation to break DNA and identifies the location of genes based on the absence of recombination between markers. Sequence mapping employs DNA sequencing technology to create detailed maps of gene locations.
Additional insight into the human genome was provided by the Human Genome Project, which helped in identifying thousands of genes and their protein products. The project illustrated how noncoding regions of DNA may be regulatory elements, and even sequences once considered 'junk' may play a crucial role in genome evolution.