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Equation 9 · Part 2 · The Peacock Problem: Darwin's Second Theory and Its Hard Tests

Symbol bart

Δtˉ=ht2 βt+B βpΔpˉ=B βt+hp2 βp\begin{aligned} \Delta \bar{t} &= h_t^{2}\,\beta_t + B\,\beta_p \\ \Delta \bar{p} &= B\,\beta_t + h_p^{2}\,\beta_p \end{aligned}
tˉ\bar{t}

What this part means

bart is part of the quantity the equation computes from the expression on the right.

Its job in the formula

bart is part of the quantity the equation computes from the expression on the right.

The passage around this formula

Russell Lande’s 1981 paper gave this verbal logic its standard quantitative-genetic form, modelling the joint evolution of a female preference trait and a male display trait under stabilising natural selection on the display and showed that, “despite stabilizing natural selection on males, various types of mating preferences may create a runaway process in which the outcome of phenotypic evolution depends critically on the genetic variation parameters and initial conditions of a population” [ 4 ] . One compact way to see why sits in the coupling itself. Let tˉ\bar t be the population mean of a male display trait and pˉ\bar p the population mean of the corresponding female preference; write…

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Sources cited in the surrounding passage

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