Equation 3 · Part 1 · From Origins to Frontier: A History of Evolutionary Biology and Ecology
Symbol p
What this part means
the frequency.
Its job in the formula
p is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol p→Article meaning
Where the article explains it
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 = .
The passage around this formula
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 deleterious, and the smaller the effective population, the faster that random fixation proceeds. Wright’s “shifting balance” framework, in which small subpopulations explore a rugged fitness landscape partly by drift and partly by selection, remains debated in its strong form, but the underlying mathematics of drift is uncontroversial and became a permanent part of population genetics.
Learn the underlying idea
A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.
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Sources cited in the article section
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