Haplotype in the context of "Most recent common ancestor"

The Italian wolf (Canis lupus italicus or Canis lupus lupus), also known as the Apennine wolf, is a subspecies of the grey wolf native to the Italian Peninsula. It inhabits the Apennine Mountains and the Western Alps, though it is undergoing expansion towards the north and east. As of 2022 the wolf population within Italy is estimated to be 3,307 individuals. Although not universally recognised as a distinct subspecies, it nonetheless possesses a unique mtDNA haplotype and a distinct skull morphology.

It has been strictly protected in Italy since the 1970s, when the population reached a low of 70–100 individuals. The population is increasing in number, though illegal hunting and persecution still constitute a threat. Since the 1990s, the Italian wolf's range has expanded into southeastern France and Switzerland.

The genetic history of the Indigenous peoples of the Americas is divided into two distinct periods: the initial peopling of the Americas from about 20,000 to 14,000 years ago (20–14 kya), and European contact, after about 500 years ago. The first period of the genetic history of Indigenous Americans is the determinant factor for the number of genetic lineages, zygosity mutations, and founding haplotypes present in today's Indigenous American populations.

Indigenous American populations descend from and share ancestry with an Ancient East Asian lineage which diverged from other East Asian peoples prior to the Last Glacial Maximum (26–18 kya). They also received geneflow from Ancient North Eurasians, a distinct Paleolithic Siberian population with deep affinities to both "European hunter-gatherers" (e.g. Kostenki-14) and "Basal East Asians" (e.g. Tianyuan man). They later dispersed throughout the Americas after about 16,000 years ago (exceptions being the Na-Dene and Eskimo–Aleut speaking groups, which are derived partially from Siberian populations which entered the Americas at a later time).

A most recent common ancestor (MRCA), also known as a last common ancestor (LCA) or concestor (a term coined by Nicky Warren), is the most recent individual from which all organisms of a set are inferred to have descended. The most recent common ancestor of a higher taxon is generally assumed to have been a species. The term is also used in reference to the ancestry of groups of genes (haplotypes) rather than organisms.

The ancestry of a set of individuals can sometimes be determined by referring to an established pedigree, although this may refer only to patrilineal or matrilineal lines for sexually-reproducing organisms with two parents, four grandparents, etc. However, in general, it is impossible to identify the exact MRCA of a large set of individuals, but an estimate of the time at which the MRCA lived can often be given. Such time to most recent common ancestor (TMRCA) estimates can be given based on DNA test results and established mutation rates as practiced in genetic genealogy, or by reference to a non-genetic, mathematical model or computer simulation.

Genetic association is when one or more genotypes within a population co-occur with a phenotypic trait more often than would be expected by chance occurrence.

Studies of genetic association aim to test whether single-locus alleles or genotype frequencies or more generally, multilocus haplotype frequencies differ between two groups of individuals (usually diseased subjects and healthy controls). Genetic association studies are based on the principle that genotypes can be compared "directly", i.e. with the sequences of the actual genomes or exomes via whole genome sequencing or whole exome sequencing. Before 2010, DNA sequencing methods were used.

A diversity index is a method of measuring how many different types (e.g. species) there are in a dataset (e.g. a community). Diversity indices are statistical representations of different aspects of biodiversity (e.g. richness, evenness, and dominance), which are useful simplifications for comparing different communities or sites.

When diversity indices are used in ecology, the types of interest are usually species, but they can also be other categories, such as genera, families, functional types, or haplotypes. The entities of interest are usually individual organisms (e.g. plants or animals), and the measure of abundance can be, for example, number of individuals, biomass or coverage. In demography, the entities of interest can be people, and the types of interest various demographic groups. In information science, the entities can be characters and the types of the different letters of the alphabet. The most commonly used diversity indices are simple transformations of the effective number of types (also known as 'true diversity'), but each diversity index can also be interpreted in its own right as a measure corresponding to some real phenomenon (but a different one for each diversity index).