Natural Selection and Useless Structures

Natural Language and Natural Selection

Many people have argued that the evolution of the human language faculty cannot be explained by Darwinian natural selection. Chomsky and Gould have suggested that language may have evolved as the by-product of selection for other abilities or as a consequence of as-yet unknown laws of growth and form. Others have argued that a biological specialization for grammar is incompatible with every ten...

Useless Disinfection

Grandmothering and natural selection.

Humans are unique among primates in that women regularly outlive their reproductive period by decades. The grandmother hypothesis proposes that natural selection increased the length of the human post-menopausal period-and, thus, extended longevity-as a result of the inclusive fitness benefits of grandmothering. However, it has yet to be demonstrated that the inclusive fitness benefits associat...

Maladaptation and natural selection.

The transformations George Williams initiated in evolutionary biology seem so blindingly obvious in retrospect that they spur the question of why he saw what no one else did. While most humans are prone to see only what theory predicts, Williams sees in bold relief whatever does not fit. Not an adaptationist or an anti-adaptationist, Williams is better described as a maladaptionist. The challen...

Natural selection and speciation.

A paper by Korol et al. (1) in this issue demonstrates significant premating reproductive divergence between Drosophila melanogaster populations adapted to distinct, but closely adjacent, habitats in ‘‘Evolution Canyon’’ on Mt. Carmel, Israel. The authors suggest that reproductive isolation has evolved in situ as a result of adaptive divergence in response to the contrasting environments of nor...