Towards a mechanistic understanding of variation in aquatic food chain length.

Ecologists have long sought to understand variation in food chain length (FCL) among natural ecosystems. Various drivers of FCL, including ecosystem size, resource productivity and disturbance, have been hypothesised. However, when results are aggregated across existing empirical studies from aquatic ecosystems, we observe mixed FCL responses to these drivers.

Transgressive segregation in mating traits drives hybrid speciation.

Hybridization can rapidly generate novel genetic variation, which can promote ecological speciation by creating novel adaptive phenotypes. However, it remains unclear how hybridization, creating novel mating phenotypes (e.g.

Range expansions of sexual versus asexual organisms: Effects of reproductive assurance and migration load.

It is generally considered that sexual organisms show faster evolutionary adaptation than asexual organisms because sexuals can accumulate adaptive mutations through recombination. Yet, empirical evidence often shows that the geographic range size of sexual species is narrower than that of closely related asexual species, which may seem as if asexuals can adapt to more varied environments. Two potential explanations for this apparent contradiction considered by the existing theory are reproduction assurance and migration load.

Increased Floral Rewards due to Local Adaptation Drives Plant Ecological Speciation via Learned Preferences of Pollinators.

AbstractIn animal-pollinated plants, the growth environment and pollination environment are two important agents of natural selection. However, their simultaneous effects on plant speciation remain underexplored. Here, we report a theoretical finding that if plants' local adaptation to the growth environment increases their floral rewards for pollinators, it can strongly facilitate ecological speciation in plants.