Climate change does not occur symmetrically; instead, in a process called polar amplification, polar areas warm faster than the tropics. Recent work indicated that transport processes in the upper atmosphere account for much of the recent polar amplification, but this conclusion proved controversial. Here, updated reanalysis data have been used to show that reductions in sea ice are instead responsible

Self-fertilisation (selfing) in plants is prevented mainly by the self-incompatibility recognition system, which consists of male and female specificity genes and modifier genes. Selfing does occur in Arabidopsis plants, but it is not known how it arose. Here it is reported that selfing in Arabidopsis results from a geographically widespread, 213-base-pair inversion within the male specificity gene. When this inversion is returned to its original orientation, selfing is prevented once more

Studies of identical twins are widely used to dissect the contributions of genes and the environment to human diseases. In multiple sclerosis, an autoimmune demyelinating disease, identical twins often show differences. This might suggest that environmental effects are most significant in this case, but genetic and epigenetic differences between identical twins have been described. Here, however, studies of identical twins show no evidence for genetic, epigenetic or transcriptome differences that could explain disease discordance