Biology Reference
In-Depth Information
Chapter 14
Principles and Mechanisms
of Biological Evolution
The year 2010 marked the 150th anniversary of the historic publication of Darwin's
(1809-1882) “Origin of Species” in which he proposed his
theory of evolution by
natural selection
(Darwin 1859). Evolution (to be defined below) is a controversial
topic (Miller 2008; Carroll 2006) and has been attracting the interest of both
scientists and lay public, ranking among the most widely discussed subjects on
the Internet (see Table
14.1
). For example,
evolution theory
has been visited by
more people than
Einstein's relativity theory
as of August 2009 and is comparable
to the topic of Obama's cabinet in the number of visitors.
There are two kinds of empirical data that are involved in debates on evolution -
macroscopic (or phenomenological) data such as those Darwin collected during his
5-year trip (1831-1836) around the world on the HMS Beagle including
the Galapagos Islands, and microscopic (or molecular) data such as those on the
role of DNA in genetic inheritance that became available about a century after
the publication of Darwin's
macroscopic
theory of evolution. Since fact-based
debates on evolution must utilize either one or both of these two kinds of empirical
data, we can logically divide all debates on evolution into
four
main classes or
categories, depending on the kinds of empirical data that inform the debates (see
Table
14.2
).
All the debates on evolution before molecular biology began around the mid-
twentieth century and belong to what may be referred to as the Type I debates (see
the third row in Table
14.2
). The
evolution-creation debates
that began in Darwin's
days and continue today (see Row 3 in Table
14.1
) are mostly between scientists
and some Christians and exemplify the Type I evolutionary debates. Macroscopic
data on evolution are of such a nature that they may not be able to provide an
objective basis for rationally resolving any Type I evolutionary debates. In contrast,
new kinds of debates, here called Types II and III, arose as the results of analyzing
experimental data on the molecular biology of inheritance that began most notably
with the discovery of DNA double helix by Watson and Crick (1953) and the
subsequent discovery of the genetic code (see Table
11.11
), and these debates are
waged among biologists and other scientists and have the potentials of being
resolved rationally, unlike Type I debates.
