Alleles have identity by type (ibt) if they have the same phenotypic effect. Alleles that are identical by type fall into two groups; those that are identical by descent (ibd) because they arose from the same allele in an earlier generation; and those that are non-identical by descent (nibd) because they arose from separate mutations.

External links

• http://darwin.eeb.uconn.edu/eeb348/lecture-notes/identity.pdf
• http://zwets.com/pedkin/thompson.pdf

Classical genetics