Equation 6 · Part 8 · From Origins to Frontier: A History of Evolutionary Biology and Ecology
Numerator: p_t(1+s)
What this part means
The complete quantity above the fraction bar.
Its job in the formula
occurs above the fraction bar. The numerator is divided by the entire denominator below it.
Full expression→Numerator: p_t(1+s)→Article meaning
The passage around this formula
A basic case illustrates the kind of prediction this apparatus makes possible. For a single locus with two alleles under simple directional selection with selection coefficient s favoring an allele at frequency p , one classical discrete-generation recursion is . This is a deliberately simplified model — haploid, one locus, constant s , no drift, no linkage — and real populations violate several of its assumptions routinely. Its value is not as a literal forecast of any specific population but as a baseline against which departures (frequency-dependent selection, epistasis, drift-dominated dynamics in small populations) can be identified and measured.
Learn the underlying idea
A fraction a/b means a divided by b. The top number is the numerator; the bottom number is the denominator, and it cannot be zero.
Open the illustrated fractions: division written vertically guide →
Sources cited in the article section
These citations provide research context; check each source for the exact claim it supports.