A Historical Study on Ronald Aylmer Fisher’s “Fundamental Theorem of Natural Selection”
This study examines the "Fundamental Theorem of Natural Selection" (hereafter, the Theorem), first introduced by Ronald Aylmer Fisher in his 1930 book The Genetical Theory of Natural Selection. Fisher formulated the theorem as: "The rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time." He regarded this theorem as a biological law and attributed significant importance to it. Despite this, the theorem was largely overlooked and frequently misunderstood for decades. It was not until nearly fifty years after its publication that a consensus emerged confirming its mathematical validity and its indication of a biological regularity. Among those who supported this view was E. W. Ewens, a prominent geneticist. However, in a 2024 publication, Ewens reversed his position, arguing that the theorem is flawed and should be removed from scientific literature.The validity and significance of Fisher’s Theorem remain subjects of debate. This study aims to trace the historical background of the theorem, the context in which it emerged, its trajectory in the history of biology, and its reception and reinterpretation over time.
Nefise BARAK
