Equation 2 · Part 3 · Hominin Evolution and Deep Prehistory: A First-Principles Introduction

Symbol P_2

\hat{f} = \frac{\sum_{i} (P_2(i) - P_1(i))\,(P_4(i) - P_1(i))}{\sum_{i} (P_3(i) - P_1(i))\,(P_4(i) - P_1(i))}

P_2

What this part means

$P_2$ occurs above the fraction bar. The numerator is divided by the entire denominator below it.

Its job in the formula

$P_2$ occurs above the fraction bar. The numerator is divided by the entire denominator below it.

Full expressionSymbol P_2Article meaning

The passage around this formula

…are allele frequencies at site i in an outgroup, a candidate-admixed population, a comparison population without the admixture, and the archaic source, respectively. The estimator exploits a simple logic: if population $P_2$ has interbred with the archaic lineage $P_4$ and $P_3$ has not, $P_2$ should share systematically more rare variants with $P_4$ than $P_3$ does, in proportion to the fraction of its genome that traces to that admixture event. This is why admixture claims in the literature are reported as percentages with…

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Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

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Sources cited in the article section

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