STAYING SAFE FROM SUNBURN

A compound first discovered in fish eggs might lead to the development of novel sunscreens, according to new research.

Gadusol protects cells by filtering ultraviolet radiation from sunlight. Fish were thought to obtain it from their diets, but it turns out that not only can they manufacture it themselves, but so too can amphibians, reptiles and birds.

Mammals, though, cannot – the evolution of fur may have rendered it obsolete. So the most famous user of natural sunscreen, the hippopotamus, has had to come up with different compounds. The researchers have also managed to produce gadusol artificially, raising the possibility of using it in a prophylactic sunburn pill. In 2012 Stirling University’s Mario Vallejo-Marin discovered a new monkeyflower in Scotland. Mimulus peregrinus was the result of hybridisation between two imported monkeyflowers (Agenda, Autumn 2012). The parent species were known to produce sterile hybrids, but he found that a Lanarkshire population of hybrids had mutated to re-enable sexual reproduction and embark on their own evolutionary trajectory.

“Usually sterile hybrids don’t do very well,” he said. “But sterile monkeyflower hybrids are very common. So I had this gut feeling that somewhere out there were other fertile hybrids.”

Indeed he has now found hybrids in Orkney that have performed the same trick. The Orkney and Lanarkshire populations are sexually compatible and produce fertile offspring – they belong to the same new species, even though they evolved quite independently. Though ‘biodiversity’ is now often used to describe what we once called ‘wildlife’, the terms are not entirely interchangeable. Biodiversity describes the variety of life at all levels of biological organisation – so it could refer to genetic variations within a species, the sheer range of species that exist or the different types of ecosystem. Efforts to measure and quantify this variety are behind concepts such as biodiversity hotspots and ecosystem services (the ways in which nature provides for humans).