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A Molecular Perspective on the
Conservation of Diversity
CRAIG MORITZ
Department of Zoology and Entomology and the Cooperative Research Centre for Tropical
Rainforest Ecology and Management, The University of Queensland, Qld, 4072, Australia
Abstract
The need to protect genetic variation, along with other hierarchical levels of biological diversity, is identified in numerous international conventions and national
policies, but the concepts and information needed to achieve this goal are deficient.
In a constantly changing world, conservation planning should seek to maintain
evolutionary processes and the ecological function of systems essential to achieve
this. For the purposes of assessment of conservation values of areas, I suggest that
genetic diversity should be partitioned into adaptive and historical components.
Surrogates such as morphological differentiation (e.g. congruent distributions of
subspecies) tend to reflect the adaptive rather than the historical component of
genetic diversity. Subject to ongoing viability of populations, the former is replaceable, whereas the latter is not. It follows that the identification of historically isolated communities through comparative phylogeography or, perhaps, environmental modelling is an important component of conservation assessments. This paper
illustrates the application of comparative phylogeography to conservation assessments through two case studies; rainforest fauna in the wet tropics of Australia, and
forest-dwelling herpetofauna in South-cast Queensland. In both systems, mtDNA
diversity is strongly partitioned among populations in a manner broadly consistent
with environmental modelling, although they differ in the extent to which historical vicariance defines congruent distributions of diversity. Areas prioritised for
conservation should encompass these historically isolated communities, together
with strong environmental gradients within each.
Key words. genetic diversity, phylogeography, conservation priorities, rainforests, mitochondrial DNA (mtDNA), adaptation, historical biogeography, environmental gradients, vertebrates, reptiles, amphibians, Evolutionarily Significant Units, evolutionary processes, historical isolation, Australia
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A Molecular Perspective on the
Conservation of Diversity
CRAIG MORITZ
Department of Zoology and Entomology and the Cooperative Research Centre for Tropical
Rainforest Ecology and Management, The University of Queensland, Qld, 4072, Australia
Abstract
The need to protect genetic variation, along with other hierarchical levels of biological diversity, is identified in numerous international conventions and national
policies, but the concepts and information needed to achieve this goal are deficient.
In a constantly changing world, conservation planning should seek to maintain
evolutionary processes and the ecological function of systems essential to achieve
this. For the purposes of assessment of conservation values of areas, I suggest that
genetic diversity should be partitioned into adaptive and historical components.
Surrogates such as morphological differentiation (e.g. congruent distributions of
subspecies) tend to reflect the adaptive rather than the historical component of
genetic diversity. Subject to ongoing viability of populations, the former is replaceable, whereas the latter is not. It follows that the identification of historically isolated communities through comparative phylogeography or, perhaps, environmental modelling is an important component of conservation assessments. This paper
illustrates the application of comparative phylogeography to conservation assessments through two case studies; rainforest fauna in the wet tropics of Australia, and
forest-dwelling herpetofauna in South-cast Queensland. In both systems, mtDNA
diversity is strongly partitioned among populations in a manner broadly consistent
with environmental modelling, although they differ in the extent to which historical vicariance defines congruent distributions of diversity. Areas prioritised for
conservation should encompass these historically isolated communities, together
with strong environmental gradients within each.
Key words. genetic diversity, phylogeography, conservation priorities, rainforests, mitochondrial DNA (mtDNA), adaptation, historical biogeography, environmental gradients, vertebrates, reptiles, amphibians, Evolutionarily Significant Units, evolutionary processes, historical isolation, Australia
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