Dinosaur Hearing, Ibex Horns and Pollination

Jennifer Ouellette at Cocktail Party Physics has an interesting take on the paper about dinosaur hearing – anything that can combine bats and dinosaurs is okay in my book!

Science Daily has an interesting article on research that relates the size of the horns of a male alpine ibex to the amount of genetic diversity:

The researchers found that horn sizes among younger ibex (one- to six-years-old) are relatively similar regardless of their genetic diversity. However, once the ibex mature to the age when they begin competing for reproductive mates (7 to 12), horn length varies according to genetic diversity: the greater the diversity, the greater the length of the horns.
The researchers believe the horn length discrepancies are evidence to support the mutation accumulation theory of ageing, which is the idea that, because natural selection weakens with age, genetic mutations have effects that accumulate over time. Therefore, differences in genetic quality become more apparent as an organism ages.

Science Daily also has an interesting article about the coevolution of nectur spurs in columbines. Typically, the evolution of nectar spurs is portrayed as an evolutionary arms race between the plant and the tongue of the pollinator. Recent research on columbines paints a different picture:

But it turns out, Whittall and Hodges found, that evolution acts in a more one-sided fashion in many plants: the plants evolve nectar spurs to match the tongue-lengths of the pollinators. Then the process stops, and only starts again when there is a change in pollinators.
Whittall and Hodges proved this idea by testing the columbine genus Aquilegia, which is pollinated by bumblebees, hummingbirds and hawkmoths.
They found that most of the columbines’ nectar spur length evolution happened during shifts in pollinators from bumblebees to hummingbirds, and from hummingbirds to hawkmoths. In between these shifts, evolution of the columbines’ nectar spurs came to a halt.

The research is being published in Nature and I may have to track this down as it sounds fascinating!

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