Genomic and fitness consequences of a near-extinction event in the northern elephant seal.

Understanding the genetic and fitness consequences of anthropogenic bottlenecks is crucial for biodiversity conservation. However, studies of bottlenecked populations combining genomic approaches with fitness data are rare. Theory predicts that severe bottlenecks deplete genetic diversity, exacerbate inbreeding depression and decrease population viability.

Principles of microscopy for ophthalmologists.

This short review begins with the theories of Airy, Rayleigh and Abbe on microscope resolution. Next, the principal developments in microscopy in the last half-century are examined for relevance to ophthalmology: confocal microscopy, photoactivation light microscopy (PALM), stochastic optical reconstruction microscopy (STORM), stimulated emission depletion (STED), structured illumination (SI), 2-photon and multiphoton excitation microscopy with a focused beam. Except for confocal, these are difficult to apply to the eye in vivo, as are the interference methods available in microscopes.

Lack of intergenerational reproductive conflict, rather than lack of inclusive fitness benefits, explains absence of post-reproductive lifespan in long-finned pilot whales.

Life-history theory suggests that individuals should reproduce until death, yet females of a small number of mammals live for a significant period after ceasing reproduction, a phenomenon known as post-reproductive lifespan. It is thought that the evolution of this trait is facilitated by increasing local relatedness throughout a female's lifetime. This allows older females to gain inclusive fitness through helping their offspring (known as a mother effect) and/or grandoffspring (known as a grandmother effect), rather than gaining direct fitness through reproducing.

The human genome harbours widespread exclusive yin yang haplotypes.

There have been reports of examples of exclusive yin yang haplotypes, differing at every locus, but there has been no systematic search for them. Unphased whole genome sequence data for 2504 unrelated 1000 Genomes subjects was searched for chains of SNPs having global minor allele frequency (MAF) > =0.1 made up of at least 20 SNPs in complete linkage disequilibrium with each other and with no pair being separated by more than 9 other SNPs.

Addressing multiscale microbial challenges using the Mesolens.

We provide a brief review of the development and application of the Mesolens and its impact on microbiology. Microbial specimens such as infected tissue samples, colonies surfaces, and biofilms are routinely collected at the mesoscale. This means that they are relatively large multimillimetre-sized samples which contain microscopic detail that must be observed to answer important questions across various sectors.