Hybridization due to changing species distributions: adding problems or solutions to conservation of biodiversity during global change?

Abstract

Background: Due to increasing global change, the rate of hybridization seems to be increasing. Question: Is hybridization adding problems or solutions to the effects of global change on biodiversity? Methods: We divided ourselves into two independent groups. Each group listed topics it thought appropriate. We then compared and combined the lists, extracting a natural structure of the topics. We next divided ourselves into three specialized subgroups and discussed the topics in more depth. In a final plenary meeting, we brought ideas together, discussed open topics, identified consensus or differences of opinion, and prepared a preliminary report. Results: Our lists of topics were highly similar, suggesting that we missed only a few topics. We agreed that it is important to consider hybridization in both its genetic and ecological contexts and with explicit attention paid to phylogenetic and biogeographic history. It is also necessary to distinguish between underlying processes and resulting consequences. Knowledge of the consequences of hybridization is more developed in genetics than in ecology. We suggest that hybridization adds problems (loss of biodiversity, ecosystem degradation) as well as solutions (new adaptive variation, ecosystem robustness) to global change challenges. Which of these applies in a given case depends on its evolutionary and environmental context, and on the objectives of conservation management. We provide five groups of questions to stimulate further research.