George C. Williams : Academic Work

Williams' 1957 paper Pleiotropy, Natural Selection, and the Evolution of Senescence is one of the most influential in 20th century evolutionary biology, and contains at least 3 foundational ideas. The central hypothesis of antagonistic pleiotropy remains the prevailing evolutionary explanation of senescence. In this paper Williams was also the first to propose that senescence should be generally synchronized by natural selection. According to this original formulation
"if the adverse genic effects appeared earlier in one system than any other, they would be removed by selection from that system more readily than from any other. In other words, natural selection will always be in greatest opposition to the decline of the most senescence-prone system."
This important concept of synchrony of senescence was taken up a short time later by John Maynard Smith, and the origin of the idea is often misattributed to him, including in his obituary in the journal, Nature. This paper also contains the first basic outline of the so-called "grandmother hypothesis", which states that natural selection might select for menopause and post-reproductive life in females, although Williams does not explicitly mention grandchildren or the inclusive fitness contribution of grandparenting.
In his first book, Adaptation and Natural Selection, Williams advocated a "ground rule - or perhaps doctrine would be a better term - ... that adaptation is a special and onerous concept that should only be used where it is really necessary", and, that, when it is necessary, selection among genes or individuals would in general be the preferable explanation for it. He elaborated this view in later books and papers, which contributed to the development of a gene-centered view of evolution; Richard Dawkins built on Williams' ideas in this area in the book The Selfish Gene.
Williams was also well known for his work on the evolution of sex, and was an advocate of evolutionary medicine.