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Connectivity over ecological and evolutionary time in coral reef fishes. Serge PLANES. Connectivity over ecological and evolutionary time Serge Planes ( planes@univ-perp.fr ).
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Connectivity over ecological and evolutionary time in coral reef fishes Serge PLANES Connectivity over ecological and evolutionary time Serge Planes (planes@univ-perp.fr)
Connectivity, why is concentrating so much effort… • Represents the scale at which populations respond to the environment. • Represents the scale at which species adapt to the environment. • Scales of management can be adjusted to dispersal distances to achieve different management goals. For example, the appropriate size and/or spacing of marine reserves as: • Harvest refugia • Conservation sanctuaries Connectivity over ecological and evolutionary time Serge Planes (planes@univ-perp.fr)
Connectivity and conservation… => Different processes, different mechanisms, different interpretations Different approaches (genetic) Connectivity over ecological and evolutionary time Serge Planes (planes@univ-perp.fr)
Genetic approach… (genetic models) Species level => phylogeny, phylogeography => mutation from common ancestor Metapopulation level => gene flow estimates => Allelic frequencies variation Population level => self recruitment => relatedness estimates Connectivity over ecological and evolutionary time Serge Planes (planes@univ-perp.fr)
Speciation and dispersal of species • Several evidences of geographix isolation • Temporal concordance among clade genesis • Temporal concordance in relation with sea-level change • Evidence of allopatry in younger clades • No sympatry found before 4 My of divergence • Absence of geographic concordance among clades => Overall modern distribution of species is not related to its age whatever their dispersal capabilities Connectivity over ecological and evolutionary time Serge Planes (planes@univ-perp.fr)
Population genetic to understand connectivity… • => No general trend among the several species surveyed • GBR, Polynesia : different out comes => Assumption of equilibrium in most computations and consider all species on a same evolutionary stage • => genetic structure cannot be directely translated into • biological and ecological outcomes Connectivity over ecological and evolutionary time Serge Planes (planes@univ-perp.fr)
Paternity approach • Numerous variable markers • Collect tissues samples of potential adults • Collect of new recruits • Need to characterise each individual (microsatellite) • Example: • A species case with 10 loci (µsat) • (independant, equilibrium, equally frequent) • => the number of potential allele combination is 10(2x10) • …. • => the probability to found 2 similar genotypes is 1/10(2x10) • => Far from most population size at regional area Allele 1 Allele 2 Allele 3 Allele 4 Allele 5 Allele 6 Allele7 10 10 10 10 10 10 10 10 10 10 10 10 10 10
Kimbe Bay case study Adult sampling
Kimbe Bay case study 2004 (Total new recruits) Overall selft-recruits 66 out of 130 (51%) Lagoon A: 15 (48%) Lagoon B: 1 Lagoon C: 0 Lagoon D: 1 Lagoon E: 9 (24%) Lagoon G: 1 Main Flux: G-C-B-A 2 G (10) 2 D (21) C (10) 2 3 B (20) 2 3 1 4 6 E (37) 9 A (31) 3 2 15 F (1)
Kimbe case study Turae 6% 71 2 34 Kapepa 4 Kimbe 3 Restoff 3% 2 10% 39 Wulai 1 59 11 Schuman