An essay on the necessity and feasibility of conservation genomics

Abstract

The basic premise of conservation genetics is that small populations may be genetically threatened. The two steps leading to this premise are: (1) due to prominent influence of random genetic drift and inbreeding allelic and genotypic diversity in small populations is expected to be low, and (2) low allelic diversity and high homozygosity are expected to lead to immediate fitness decreases (inbreeding depression) and a compromised potential for evolutionary adaptation. Conservation genetic research has been strongly stimulated by the application of neutral molecular markers like microsatellites and AFLPs. In general these marker studies have provided evidence for step 1. It is less evident how these markers may provide evidence for step 2. In this essay we argue that, in order to get detailed insight in step 2, adopting a conservation genomic approach, in which conservation genetics will use approaches from ecological and evolutionary functional genomics (ecogenomics), is both necessary and feasible. Conservation genomics is necessary for studying functional genomic variation as function of drift and inbreeding, for studying the mechanisms that relate low genetic variation to low fitness, for integrating environmental and genetic approaches to conservation biology, and for developing modern, fast monitoring tools. The rapid technical and financial developments in genomics currently make conservation genomics feasible, and will improve feasibility in the very near future even further. We therefore argue that conservation genomics personifies part of the near future of conservation genetics.

Compromising genetic diversity in the wild: unmonitored large-scale release of plants and animals

“…Using thousands of single nucleotide polymorphisms (SNPs) will provide more power for studies of micro-evolutionary dynamics. Secondly, genomics will allow identifying and monitoring of genes under selection, enabling more direct assessments of the effects of large-scale releases on fitness and long-term evolutionary potential [42]. Third, genomics can help identify the mechanisms of adaptation.…”

“…Fourth, genomics will provide more sensitive tools to monitor populations under threat from large-scale releases. Ouborg et al [42] suggest that it will soon be possible to design microarrays that allow detection of specific gene-expression profiles for monitoring purposes. Sample analysis is becoming faster and less expensive.…”

Conservation and Monitoring of Tree Genetic Resources in Temperate Forests

“…is a common rescue strategy in conservation. The presence or the deliberate introduction of gene flow is however risky: high levels of gene flow may cause outbreeding depression by introducing potentially maladapted genes which in turn may reduce the adaptive capability of local populations [38,39]. Consequently, the conservation of small populations is a tricky issue.…”

“…Conservation genomics has the goals of evaluating functional genomic variation in relation to drift and inbreeding and studying the mechanisms that relate low genetic variation to low fitness [39]. Conservation genomic studies in trees are still scarce, in spite of a universal acceptance of their value and potential [3, 12••, 27, 38-41] and despite reports indicating the vulnerability of in situ forest conservation due to climatic change [42].…”

An introduction to and a reflection on the “ecogenomics promise”

“…Genes that respond to environmental stresses (such as fluctuations in temperature and oxygen availability or environmental pollutions) can act as early indicators for monitoring environmental quality and the biological availability of stressors. These can then be used as warning systems for changes in the environmental health (Ouborg et al 2010).…”