title: Interspecific interactions through 2 million years: are competitive outcomes predictable?
abstract: Ecological interactions affect the survival and reproduction of individuals. However, ecological interactions are notoriously difficult to measure in extinct populations, hindering our understanding of how the outcomes of interactions such as competition vary in time and influence long-term evolutionary changes. Here, the outcomes of spatial competition in a temporally continuous community over evolutionary timescales are presented for the first time. Our research domain is encrusting cheilostome bryozoans from the Wanganui Basin of New Zealand over a ca 2 Myr time period (Pleistocene to Recent). We find that a subset of species can be identified as consistent winners, and others as consistent losers, in the sense that they win or lose interspecific competitive encounters statistically more often than the null hypothesis of 50%. Most species do not improve or worsen in their competitive abilities through the 2 Myr period, but a minority of species are winners in some intervals and losers in others. We found that conspecifics tend to cluster spatially and interact more often than expected under a null hypothesis: most of these are stand-off interactions where the two colonies involved stopped growing at edges of encounter. Counterintuitively, competitive ability has no bearing on ecological dominance.
authors: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway Natural History Museum, University of Oslo, Oslo, Norway l.h.liow@ibv.uio.no.
authors: Lee Hsiang
authors: 0000-0002-3732-6069
authors: LH
authors: Liow
authors: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway Department of Earth Sciences, Natural History Museum, Cromwell Road, SW7 5BD London, UK.
authors: Emanuela
authors: E
authors: Di Martino
authors: Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway.
authors: Kjetil Lysne
authors: 0000-0003-2556-3080
authors: KL
authors: Voje
authors: 6702 State Highway, 12 RD 3, Kaikohe 0473, New Zealand.
authors: Seabourne
authors: S
authors: Rust
authors: Department of Earth Sciences, Natural History Museum, Cromwell Road, SW7 5BD London, UK.
authors: Paul D
authors: 0000-0002-3127-080X
authors: PD
authors: Taylor
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002013:Bryozoa / Q000145:classification*; D003163:Competitive Behavior; D009520:New Zealand
keywords: Pleistocene; cheilostome bryozoans; ecological interactions; spatial competition