7
The Theory and Practice of the
Science of Biodiversity:
A Personal Assessment
OTTO T. SOLBRIG
Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity
Ave., Cambridge, MA 02138, USA
Abstract
Diversity is a property, not an entity in itself. It refers to the property of a set of
objects of not being identical, of varying one from another in one or more characteristics. When applied to organisms, it refers to the universal attribute of all living
things that each individual being is unique, that is, no two organisms are identical.
The origin of this variability is to be found in the basic and fundamental property of
the DNA molecule that the order of the bases does not affect the free energy of the
molecule, in other words all combinations of the four bases that form the genetic
code are chemically equally viable. This characteristic combined with natural selection allows the acquisition and accumulation of favorable mutations, and in the
approximately 3 thousand million years that life has existed on Earth these processes have produced the enormous biological variation that we see today, which is
at best only a very small percentage of all the variation that has existed in the past.
Today this diversity of life is threatened by human activities, although the exact
rate of species loss is difficult to ascertain. And species loss is only one aspect of the
profound transformation of the terrestrial landscape that is presently taking place,
brought about by the growth of human populations and their economic activities.
This transformation extends from genes to ecosystems. The transformation of the
world's habitats by people has many causes, and many effects. As long as there is
doubt regarding the exact mechanism underlying this transformation, there will be
differences of opinion concerning the impact, and people who always are reluctant
to change their behavior will use these varying opinions to rationalize their actions.
Key words. agriculture, bio-ethics, diversity, evolution, landscape transformation
107
The Theory and Practice of the
Science of Biodiversity:
A Personal Assessment
OTTO T. SOLBRIG
Department of Organismic and Evolutionary Biology, Harvard University, 22 Divinity
Ave., Cambridge, MA 02138, USA
Abstract
Diversity is a property, not an entity in itself. It refers to the property of a set of
objects of not being identical, of varying one from another in one or more characteristics. When applied to organisms, it refers to the universal attribute of all living
things that each individual being is unique, that is, no two organisms are identical.
The origin of this variability is to be found in the basic and fundamental property of
the DNA molecule that the order of the bases does not affect the free energy of the
molecule, in other words all combinations of the four bases that form the genetic
code are chemically equally viable. This characteristic combined with natural selection allows the acquisition and accumulation of favorable mutations, and in the
approximately 3 thousand million years that life has existed on Earth these processes have produced the enormous biological variation that we see today, which is
at best only a very small percentage of all the variation that has existed in the past.
Today this diversity of life is threatened by human activities, although the exact
rate of species loss is difficult to ascertain. And species loss is only one aspect of the
profound transformation of the terrestrial landscape that is presently taking place,
brought about by the growth of human populations and their economic activities.
This transformation extends from genes to ecosystems. The transformation of the
world's habitats by people has many causes, and many effects. As long as there is
doubt regarding the exact mechanism underlying this transformation, there will be
differences of opinion concerning the impact, and people who always are reluctant
to change their behavior will use these varying opinions to rationalize their actions.
Key words. agriculture, bio-ethics, diversity, evolution, landscape transformation
107