Conservation Value of Independently Evolving Units: Sacred Cow or Testable Hypothesis?

Many published scientific papers use molecular marker data to identify genetically distinct populations and some go on to advocate conserving each of these populations to preserve genetic diversity. An often unacknowledged assumption underlying this approach is that patterns at marker loci reflect the distribution of among-population variation that increases evolutionary fitness and thus has conservation value. The article stresses the need for empirical testing of this assumption and provides background information by exploring the concept of conservation value and reviewing available evidence on the relationship between marker variation and characters important to fitness. Two important specific questions requiring research are identified.