God of Life: Contemplating Evolution, Ecology, Extinction

Article excerpt

"For if one link in nature's chain might be lost, another might be lost, until the whole of things will vanish by piecemeal."

--Thomas Jefferson

Contemplation of the "God of life" provides the opportunity for reflection on themes of evolution, ecology, and species extinction. Perhaps linking the "God of life" theme with extinction seems strange, but extinction is a natural part of evolution (as will be shown below), an essential life process on earth, and thus death becomes a means by which natural processes occur. This paper will focus on four major themes that are all related to this issue:

* Evolution is the unifying theory within biology, and nothing in biology makes sense without it.

* Evolution is tightly linked to ecology, and failure to accept evolution often leads to a failure to accept ecological principles.

* Extinction is a part of evolution of life on earth; human causes may be responsible for extinctions of many species.

* In recent years, human activity has accelerated climate change leading to an alarming rate of extinctions.

The goal of this chapter is to weave these themes together from both a scientific and a religious perspective to demonstrate the importance of concerns about extinction as they relate to ecology and evolution and finally to relate them to the "God of life" theme that resonates throughout this volume.

Evolution as the Unifying Theory of Biology

In the broad sense, evolution can merely describe change in social and political systems. Biological evolution, on the other hand, is the change in populations that transcends the lifetime of any individual. Individuals do not evolve, populations do. As Futuyama noted, "The changes in populations that are considered evolutionary are those that are inheritable via the genetic material from one generation to the next." (1) Darwin himself proposed much of this definition, although DNA had not been identified as the genetic material at his time. (2) His general view was that there was a common ancestry for life on earth, that species develop from common ancestors through the induction of mutations, and that natural selection accounts for the survival of organisms best suited for a given environment. Species extinction was a key component of Darwin's model; those species that were not best-suited for a given environment would eventually survive poorly in the environment and become extinct.

Theodosius Dobzhansky, the noted Harvard biologist and son of an Orthodox priest, summed it up well in his famous statement that nothing in biology makes sense unless it is understood in the light of evolution:

   Let me try to make crystal clear what is established beyond
   reasonable doubt, and what needs further study, about evolution.
   Evolution as a process that has always gone on in the history of
   the earth can be doubted only by those who are ignorant of the
   evidence or are resistant to evidence, owing to emotional blocks or
   to plain bigotry. By contrast, the mechanisms that bring evolution
   about certainly need study and clarification. There are no
   alternatives to evolution as history that can withstand critical
   examination. Yet we are constantly learning new and important facts
   about evolutionary mechanisms. (3)

Many approaches have been used by modern science to utilize information that is derived from evolutionary biology. Rational drug design involves studies of relationship trees of genes and proteins from multiple species. Examination of responses to drugs, radiation, and other toxic agents among multiple species helps to elucidate mechanisms that would be impossible to uncover in humans. During the past 20 years, scientists have sequenced 69 different human genomes, and genomes of thousands of different species. (4) The cross-species comparisons of this information have shown overwhelming support for evolutionary theory. …