“Diversification of trait combinations in coevolving plants and insect lineages”

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John N. Thompson, Christopher Schwind, and Magne Friberg

Coevolution between plants and pollinators varies among ecosystems and among closely related species

A Greya politella moth laying eggs into a flower of a woodland star (Lithophragma cymbalaria) while simultaneously pollinating the plant with pollen that adhered to her abdomen during the previous flower she visited. Part of the flower has been cut to show the floral interior.
(Credit: John N. Thompson)

The ever-changing web of life is woven from the pattern of coevolving relationships among species. Even different populations of a species may coevolve with different numbers of other species. Woodland stars (Lithophragma spp.) have coevolved with highly specialized moths that simultaneously pollinate the same flowers in which they lay their eggs. Some woodland star populations rely on a single Greya moth species for pollination, whereas others rely on two Greya moth species that differ in how they pollinate the flowers. Plants and moths from ecosystems with only one woodland star species and one Greya moth species differ in floral and moth sizes and shapes from ecosystems in which two Greya moth species use the same woodland star plants. Similar effects of moth co-occurrence are found among ecosystems in multiple woodland star species. This study suggests that some of the complexity and, potentially, resilience of the web of life results from relentless evolutionary change in which natural selection reshapes the relationships among species in ecosystem after ecosystem. The results also suggest that, just as with the conservation of species, the conservation of coevolving interactions may be enhanced by conserving the multiple (co)evolutionary solutions that have arisen among populations of each species. Read the Article