7. Theory and Practice of Biodiversity
109
2 Landscape Transformation
Planet Earth is a blend of living and non-living elements interacting in innumerable ways that result in a variety of landscapes and ecosystems. This amalgam is
very dynamic, both in time and in space, and is constantly changing, unfolding,
and producing new combinations. The living elements -living by nature of their
capacity to self-reproduce -- come in a great variety of forms, shapes, and complexities, that are continuously changing and evolving, comprising the diversity of
life.
Cosmic factors and local geological forces have sustained the process of ecosystem evolution. Organisms have in turn molded the process by modifying the characteristics of their surroundings. The most significant of these changes is probably
the transformation by photosynthetic bacteria of the atmosphere of the Earth from a
reducing to an oxidizing one, that reached present levels about a thousand million
years ago. Humans, late arrivals to this series of events, have of late become important transformers of natural landscapes, although nothing they have done or are
likely to do, other than an atomic holocaust, can match the transformation of the
atmosphere by the early photosynthetic bacteria. Yet there are some parallels. Although transformation of the atmosphere from a reducing to an oxidizing one did
not eliminate all anaerobic organisms, it reduced them significantly, both in numbers, biomass, and relative importance, and opened the way for an entire new biological world dominated by oxygen breeding, multicellular plants and animals.
Today people are transforming the surface of the globe at such an accelerated pace
that they have launched a new phase in the evolution of the planet. This new condition is characterized by the dominance of one species, our own, over all others, to
an extent never before experienced on Earth. Because of our ability to transform
landscapes, we, humans, are in a situation where we can choose to jeopardize our
own existence as well as that of innumerable other species, or we can select to
achieve a more harmonious coexistence with our biological and abiological surroundings. This presents us with an ethical and moral choice to which I return
further on.
The transformation of the world's habitats by people has many causes, and
many effects. My talk today will analyze some of these and the role that scientific
knowledge can play in ameliorating the human impact on the environment.
3 The Process of Transformation
We transform our surroundings to suit them to our needs when we build structures
such as houses, factories or roads, and especially when we replace natural vegetation and fauna with agro-ecosystems and pastures for our domestic animals; we
further transform landscapes when we extract natural resources, be they renewable
such as timber, or non-renewable such as oil or minerals. In short, the transformation of the Earth's landscapes is the result of our economic activities. And our
109
2 Landscape Transformation
Planet Earth is a blend of living and non-living elements interacting in innumerable ways that result in a variety of landscapes and ecosystems. This amalgam is
very dynamic, both in time and in space, and is constantly changing, unfolding,
and producing new combinations. The living elements -living by nature of their
capacity to self-reproduce -- come in a great variety of forms, shapes, and complexities, that are continuously changing and evolving, comprising the diversity of
life.
Cosmic factors and local geological forces have sustained the process of ecosystem evolution. Organisms have in turn molded the process by modifying the characteristics of their surroundings. The most significant of these changes is probably
the transformation by photosynthetic bacteria of the atmosphere of the Earth from a
reducing to an oxidizing one, that reached present levels about a thousand million
years ago. Humans, late arrivals to this series of events, have of late become important transformers of natural landscapes, although nothing they have done or are
likely to do, other than an atomic holocaust, can match the transformation of the
atmosphere by the early photosynthetic bacteria. Yet there are some parallels. Although transformation of the atmosphere from a reducing to an oxidizing one did
not eliminate all anaerobic organisms, it reduced them significantly, both in numbers, biomass, and relative importance, and opened the way for an entire new biological world dominated by oxygen breeding, multicellular plants and animals.
Today people are transforming the surface of the globe at such an accelerated pace
that they have launched a new phase in the evolution of the planet. This new condition is characterized by the dominance of one species, our own, over all others, to
an extent never before experienced on Earth. Because of our ability to transform
landscapes, we, humans, are in a situation where we can choose to jeopardize our
own existence as well as that of innumerable other species, or we can select to
achieve a more harmonious coexistence with our biological and abiological surroundings. This presents us with an ethical and moral choice to which I return
further on.
The transformation of the world's habitats by people has many causes, and
many effects. My talk today will analyze some of these and the role that scientific
knowledge can play in ameliorating the human impact on the environment.
3 The Process of Transformation
We transform our surroundings to suit them to our needs when we build structures
such as houses, factories or roads, and especially when we replace natural vegetation and fauna with agro-ecosystems and pastures for our domestic animals; we
further transform landscapes when we extract natural resources, be they renewable
such as timber, or non-renewable such as oil or minerals. In short, the transformation of the Earth's landscapes is the result of our economic activities. And our