← All parts of this equation

Equation 2 · Part 7 · From Origins to Frontier: A History of Evolutionary Biology and Ecology

subscript

Var⁡(Δp)=p(1−p)2Ne,\operatorname{Var}(\Delta p) = \frac{p(1-p)}{2N_e},
subscript

What this part means

The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.

Its job in the formula

A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.

The passage around this formula

Sewall Wright’s 1931 paper, “Evolution in Mendelian Populations,” added the piece Fisher’s and Haldane’s more deterministic treatments lacked: a formal account of genetic drift, the random change in allele frequency from generation to generation caused by finite population size [ 3 ] . Wright showed that in a randomly mating population of effective size NeN_e , the variance in allele frequency change per generation from sampling alone is Var⁡(Δp)=p(1−p)2Ne\operatorname{Var}(\Delta p) = \frac{p(1-p)}{2N_e}. for a diploid population starting at allele frequency p . This single expression carries a real consequence: small populations can fix or lose alleles by chance alone, independent of whether those alleles are beneficial, neutral, or mildly…

Read this part in the article →

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.

Open the illustrated subscripts: which member of a family? guide →

Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.