Molecular population genetics and evolution: Two neglected elements in studies on forest biodiversity

Alfred E. Szmidt

In: Measuring and Monitoring Biodiversity in Tropical and Temperate Forests, 1995, T.J.B. Boyle and B. Boontawee (eds), Center for International Forestry Research (CIFOR), Bogor, Indonesia: 177-193.

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Abstract

Biodiversity refers to the variety and variability among living organisms and the ecosystems in which they interact. Hence, it is intimately associated with their genetic system. Yet, the current research is focused on taxonomical and ecological aspects of biodiversity and usually ignores the fact that genetic effects can change species' dynamics, and species composition can change genetic dynamics. Information on genetic variation is central to the design of appropriate conservation strategies. Measurements of genetic variation are often counselled in biodiversity conservation programmes without much clarity as to the choice of methods and interpretation of results. Furthermore, many of these programmes are chiefly concerned with collection, preservation and cataloguing of genetic variation, rather than with evolutionary determinants that shape its pattern. The biological function of plants relies on an intimate interplay of three distinct genomes: nuclear, chloroplast and mitochondrial. All these genomes harbour selected as well as neutral variation. The patterns of variation at selected loci may differ from that of neutral loci. Population differentiation is also closely associated with the mode of transmission of individual genes and the extent of population differentiation is expected to vary between nuclear and cytoplasmic genes. Most available information about genetic variation in plants comes from surveys of gene marker variation. Depending on the selective significance, genomic origin and inheritance, individual markers may or may not respond to particular evolutionary determinants of this variation. Molecular methods have greatly improved our ability to study genetic variation and to discern its evolutionary significance. However, there still appears to be much confusion among biodiversity students with regard to the informativeness and feasibility of these methods for biodiversity conservation programmes. In this contribution, I briefly describe currently available methods for detection of genetic variation and suggest how they can be used in order to improve our knowledge about the genetic components of tree biodiversity.
Key words: biodiversity, evolution, molecular genetics, genetic conservation

by Alfred E. Szmidt