Is a group best off if everyone co-operates? Theory often considers this to be so (e.g. the "conspiracy of doves"), this understanding underpinning social and economic policy. We observe, however, that after competition between "cheat" and "co-operator" strains of yeast, population fitness is maximized under co-existence. To address whether this might just be a peculiarity of our experimental s...

The term "cheating" is used in the evolutionary and ecological literature to describe a wide range of exploitative or deceitful traits. Although many find this a useful short hand, others have suggested that it implies cognitive intent in a misleading way, and is used inconsistently. We provide a formal justification of the use of the term "cheat" from the perspective of an individual as a maxi...

Signals in intraspecific communication should be inherently honest; otherwise the system is prone to collapse. Theory predicts, however, that honest signalling systems are susceptible to invasion by cheats, the extent of which is largely mediated by fear of reprisal. Cuttlefish facultatively change their shape and colour, an ability that evolved to avoid predators and capture prey. Here, we sho...

Parents providing care to offspring face the same problem that exists in every biological system in which some individuals offer resources to others: cheaters, who exploit these benefits. In almost all species in which males contribute to parental care, females mate with multiple males. As a result, males frequently provide efforts for unrelated offspring at a cost to their own reproductive fit...

Resource competition within a group of cooperators is expected to decrease selection for cooperative behavior but can also result in diversifying selection for the use of different resources, which in turn could retard the breakdown of cooperation. Diverse groups are likely to be less susceptible to invasion by noncooperating social cheats: First, competition repression resulting from character...

High levels of conspecific brood parasitism are found in a communally breeding bird, with implications for the evolutionary links between brood parasitism and communal breeding. It also uncovers a novel egg recognition mechanism hosts use to foil brood parasites.

Leymus chinensis and Leymus secalinus are perennial rhizome grasses; photosynthetic physiological characteristics were compared between them in Sandy and Saline-Alkaline Soils on the Songnen Plains of China. The contents of chlorophyll and soluble saccharides were positively correlated with photosynthetic characteristics. The photosynthetic capacity of L. chinensis was significantly greater tha...