Utilisateur:ZEDiphe/Brouillon
Definition of local adaptation[modifier | modifier le code]
Local Adaptation results from the interactions between multiple evolutionary forces (selection, genetic drift, mutation, migration) and is observable within human lifetimes. Evolution of species in spatially and temporally heterogeneous environnement generate differents selective pressures. Unlike in adaptation to physical environnement, local adaptation is based on the evolution of one of the species of the interaction in response to recent evolutionary changes in the other species. That is why, there is a constant Co-adaptation to enemies (Parasitism, predation) and mutualists, selecting or maintaining the frequencey of traits that play in the survival and reproduction of individuals. This dynamic process favor local coevolution and specialization of the two partners of the interaction. Local adaptaion can be effected both on a large geographic scale (between popultations separated by hundreds kilometers), microgeographically (less than 1 kilometer) and even throught times (seasonnal change).
Modification in selection pressures can facilitate adaptation by increasing local genetic variation. Those modifications are often found in the context of antagonistic interactions, where coevolution is fast and results in ‘arms race’ in which organisms must constantly adapt, evolve, and survive against ever-evolving opposing organisms in an ever-changing environment. In such interactions, the one that evolve the most rapidly, thanks to a shorter generation time or higher mutation or migration rate, is locally adapted while the other is not. Local adaptation can be evaluated and is present when fitness is higher in sympatry than in allopatry.
Example of local adaptation[modifier | modifier le code]
- In lakes in New Zealand, Microphallus sp. trematodes are more adapted to Potamopyrgus antipodarum snails collected from shallow-water area, when they are a sexual reproduction than P. antipodarum snails coming from deep-water area with an asexual reproduction.
- Environnement stress influence the local adaptation of the daphnia magna who change their phototactic behavior and their life-history traits (body and eggs size, number of eggs) when fish predator pressures are hight.
- The soil fertility is key driver of local adaptation in arbuscular mycorrhizal (AM) symbioses. Locally adapted mycorrhizal associations are more mutualistic in phosphorus limited sites and less parasitic at nitrogen limited sites depending on plants-soils-fungi combination.
See also[modifier | modifier le code]
- Adaptation
- Allopatric speciation
- Red Queen theorie
- Maladaptation
- Mutualism
- Sympatric speciation
References[modifier | modifier le code]
- King K. C., Delph L. F., Jokela J., Lively C. M. 2011. Coevolutionary hotspots and coldspots for host sex and parasite local adaptation in a snail-trematode interaction. Oikos ; 120(9) :1335-1340=" In lakes in NZ, Microphallus sp. trematodes are more adapted to Potamopyrgus antipodarum snails collected from shallow-water area, when they are a sexual reproduction than P. antipodarum snails coming from deep-water area with an asexual reproduction."
- Boersma M., De Meester L., Spaak P. 1999. Environnemental stress and local adaptation in Daphnia magna. Limnol. Oceanogr., 44(2), 393-402.
- Johnson N. J., Wilson G. W. T., Bowker M. A., Wilson J. A., Miller M. R. 2009. Resource limitation is a driver of local adaptation in mycorrhizal symbioses. PNAS. Vol. 107, No. 5, 2093-2098.