Darwin's thinking has led us to test the theory of evolution and go beyond his mechanism of natural selection to test new explanations of genetic change and descent with modification
. A hopeful view is that the future will bring better knowledge if science maintains the freedom to discover what nature offers.
Four years after the publication of Origin, Lyell returned this intellectual courtesy and tried to make good on Darwin's hunch that the natural history of languages could provide a model for illustrating the biological process of descent with modification
. Tucked away in the back of Geological Evidences for the Antiquity of Man (1863), his chapter on the "Origin and Development of Languages and Species Compared" concludes that philology not only provides empirical evidence for the doctrine of transmutation: it also calms fears about a fossil record that refuses to play along.
Besides the problem of defining the species, the concept of descent with modification
is also fraught with several difficulties.
In response to Phillip Johnson, Eugenie Scott argued that descent with modification
and the emergence and extinction of species found in the fossil record can be explained by natural selection, differential reproduction, genetic mutation, adaptation, and other natural processes, without postulating intelligent design.
Yet if one wishes to exclude design on scientific grounds, one must do so on the basis of a demonstrated mechanism; mere descent with modification
is not enough.
Rather, selection of detail "extended over a series of years" was precisely the method that Darwin himself used to uncover a natural world whose own discursive strategy was "descent with modification
I write from the vantage of two overlapping worlds, one as an active member of a conservative evangelical (largely "creationist") Christian faith community, and the other as a university professor and scientist who has concluded beyond reasonable doubt that the evolutionary model (descent with modification
) best explains the many evidential trains that inform questions of biological origin.
Before students begin activities 1 and 2, we discuss Darwin's idea of descent with modification
and what that implies for the diversity of organisms on earth.
In two major works, On the Origin of Species (1859) and The Descent of Man (1871), Charles Darwin had presented the idea of evolution as his theory of "descent with modification
" grounded in the explanatory mechanism of natural selection or the survival of the fittest.