Income Exclusion Rule. DEFINITION of 'Income Exclusion Rule'. A rule that sets aside certain types of income as nontaxable. There are many types of income that qualify under this rule, such as life insurance death benefit proceeds, child support, welfare and municipal bond income. Income that is excluded is not reported anywhere on Form 1040.
Ancestral vs derived alleles. An ancestral allele or an ancestral trait (depending on whether you look at the phenotype or a t the genotype) is the trait/allele that was carried by the common ancestor of the taxon you consider.
In molecular evolution, a haplogroup (from the Greek: á¼ÏÎ»Î¿ÏÏ, haplous, haploÃ»s, onefold, single simple And-Proto-Proto : *germanic, kruppaz round, mass) lump is similar haplotypes that share a common ancestor having the same single nucleotide (POLYMORPHISM) snp mutation in all. haplotypesaplogroups can be used to define genetic populations and are often geographically oriented. For example, the following are common divisions for mtDNA haplogroups: 1  African: L0, L1, L2, L3, L4, L5, L6. 2  West Eurasian: H, T, U, V, X, K, I, J, W (all listed West Eurasian haplogroups are derived from macro-haplogroup N).