Digest: What keeps sexual signals honest? A general new explanation.

One of the most tantalizing phenomena in evolutionary biology has just received a new, elegant mathematical explanation. Rather than relying on the much-contested handicap principle, Fromhage and Henshaw's simple new model is based on resource trade-offs and explains why keeping costly sexual signals honest is evolutionarily optimal. Complications such as the supposed inherent wastefulness of the handicap principle, or social punishment of dishonest cheaters, are no longer needed to explain honesty in sexual signaling.

Short-term insurance versus long-term bet-hedging strategies as adaptations to variable environments.

Understanding how organisms adapt to environmental variation is a key challenge of biology. Central to this are bet-hedging strategies that maximize geometric mean fitness across generations, either by being conservative or diversifying phenotypes. Theoretical models have identified environmental variation across generations with multiplicative fitness effects as driving the evolution of bet-hedging.

Differential allocation of parental investment and the trade-off between size and number of offspring.

When parents decide how much to invest in current versus future offspring and how many offspring to divide their current investments between, the optimal decision can be affected by the quality of their partner. This differential allocation (DA) is highly dependent on exactly how partner quality affects reproductive costs and offspring benefits. We present a stochastic dynamic model of DA in which females care for a series of clutches when mated with males of different quality.