Biodiversity loss prohibits necessary evolution of species
The extinction of species may slow down or prevent the evolvement of new species, while evolution just then is needed for the recovery of the disturbed ecosystem. This is the conclusion of the first experimental study on the effect of the loss of biodiversity on evolutionary processes. The study by biologist Alexandre Jousset from Utrecht University, conducted with German and French colleagues, is reported in Science Advances on 25 June. “Our results suggest that the extinction of species may have far more long-lasting and detrimental effects than currently assumed”, first author Jousset says.
“Our study shows that the extinction of species not only reduces current ecosystem functioning and services, but may induce an evolutionary debt as well. It can slow down or prevent the evolution of new species needed to compensate the functions of the ones which went extinct. And at least as important: it may prohibit the evolution of new species needed to adopt to novel challenges such as those associated with global climate change”, Alexandre Jousset, Assistant Professor at Utrecht University explains.
Impact of vast extinction
Every species in an ecosystem fulfils a role essential for the proper functioning of the ecosystem as a whole. The vast extinction of species reported worldwide, raises the question of its impact on the biodiversity and functioning of the affected ecosystems.
Previous big data studies of changes in ecosystem biodiversity have reported both increases and decreases in the appearance of new species. However, evolutionary changes take place on much longer time scales. Jousset and colleagues therefore investigated the underlying mechanisms for the opposite outcomes of previous studies by developing an experimental approach.
Through our novel approach we have not only found support for the debated theory ‘biodiversity begets biodiversity’, but also gained more insight in the mechanisms that drive evolution.
Unifying the opposite outcomes
The biologists established bacterial communities of varying biodiversity, simulating ecosystems of different diversity on a microscopic scale. This platform allowed them to investigate, in a controlled manner, whether the opposite outcomes can be unified by taking into account the diversity of biological functions and the extent of specialisation of the remaining species.
Biodiversity stimulates evolution
They found that biodiversity stimulates the evolution of novel species when the resources in the ecosystem become increasingly scarce and the new species are able to use new, previously underutilised resources. Evolving to more efficiently use underexploited resources allows species to escape the intense completion prevailing in highly diverse communities, the authors think.
“Through our novel approach we have not only found support for the debated theory ‘biodiversity begets biodiversity’, but also gained more insight in the mechanisms that drive evolution”, Jousset concludes.
'High functional diversity stimulates diversification in experimental microbial communities'
Science Advances, embargoed until 24 June 2016 2:00 pm U.S. Eastern Time /19.00 hrs BST
Alexandre Jousset1,2,*, Nico Eisenhauer4,5, Monika Merker1, Nicolas Mouquet3 and Stefan Scheu1
1 Georg August University Göttingen, Germany
2 (address for correspondence): Utrecht University, Email: firstname.lastname@example.org
3 Institut des Sciences de l’Evolution, Montpellier, France
4 German Centre for Integrative Biodiversity Research, Leipzig, Germany
5 Institute for Biology, University of Leipzig,Leipzig, Germany
Microscope views of the colonies of the different evolved bacteria, illustrating the changes in morphology.
The pictures are downloadable. This is the highest resolution available.
Founded in 1636, Utrecht University is an international research university of the highest level with 6.700 staff members and 30.000 students. Multidisciplinary research in Utrecht focuses on four areas of expertise: Dynamics of Youth, Institutions for Open Societies, Life Sciences and Sustainability.