Preserving genes, species, or ecosystems? Healing the fractured foundations of conservation policy

The scientific foundations of conservation policy are the subject of a rece nt tripolar debate, with systematists arguing for the primacy of phylogenet ic rankings, ecologists arguing for protection at the level of populations or ecosystems, and evolutionary biologists urging more attention for the fa ctors that enhance adaptation and biodiversity. In the field of conservatio n genetics, this controversy is manifested in the diverse viewpoints of mol ecular systematists, population biologists, and evolutionary (and quantitat ive) geneticists. A resolution of these viewpoints is proposed here, based on the premise that preserving particular objects (genes, species, or ecosy stems) is not the ultimate goal of conservation. In order to be successful, conservation efforts must preserve the processes of life. This task requir es the identification and protection of diverse branches in the tree of lif e (phylogenetics), the maintenance of life-support systems for organisms (e cology), and the continued adaptation of organisms to changing environments (evolution). None of these objectives alone is sufficient to preserve the threads of life across time. Under this temporal perspective, molecular gen etic technologies have applications in all three conservation agendas; DNA sequence comparisons serve the phylogenetic goals, population genetic marke rs serve the ecological goals, quantitative genetics and genome exploration s serve the evolutionary goals.