|
Have you ever wondered how evolution produced the wing of a
bat, the foot of an amphibian, the tiny arms of the Tyrannosaurus, or the eye
and brain that allow you to read these words? Conventional wisdom would say natural
selection. But can this alone explain the subtle nuances and wonders of evolution?
Shapes of Time explores evolution from a much neglected
perspective that links natural selection and genetics. Kenneth J. McNamara delves
into the living and the fossil worlds to show how animals and plants have evolved
when the carefully orchestrated pattern of embryological development is gently
nudged off course-producing species that may have developed "beyond"
their ancestors or may have developed less, looking more like overgrown juveniles.
McNamara shows how this phenomenon -- known as heterochrony
-- has affected many aspects of evolution, including the mechanisms behind the
selection of different breeds of animals, differences between sexes, and animal
behavior. Heterchrony accounts for the "Peter Pan syndrome," in which
some species look like their ancestor's young. It explains what was really behind
the evolution of flightless birds, how the dinosaurs got so big, how pterosaurs
managed to produce wings supported only by their fourth fingers, and what has
driven the evolution of the animal closest to our hearts -- the primate species
with the biggest brain and longest childhood -- Homo sapiens. Kenneth
J. McNamara is senior curator of invertebrate paleontology at the Western Australian
Museum in Perth. He has investigated the role of heterochrony in evolution in
a wide range of living and fossil animals in Europe, Australia, China and Africa.
He is coauthor of Heterochrony: The Evolution of Ontogeny. |
