Sunday, 19 August 2012

Biology stuff from the week 13-19/8/12

Young virgin female hide beetles are responsive to the scents of invertebrate cadavers, and male pheromones, but only when in conjunction.
Males, however, will respond to cadavers alone.
This is because the young females are looking for both calories and a date, and the males are looking for calories to offer their female counterparts.

How does the extinction of one predator lead to the extinction of others? When those predators fed on different prey populations.
A study in wasps has found that when the predator of one aphid population goes extinct, the burgeoning unpredated aphid population pressurises other aphid populations, forcing their own predators to extinction.
It is because of phenomena like this that conservationists are learning to take a more ecosystem-wide approach, rather than working hard to preserve individual species.

Does evolution repaet itself? Yes -- it's called convergent evolution:

Did icthyosaurs - which definitely were not dinosaurs, PhysOrg! - get 'the bends', from rising too fast?
They did, however, develop lesions on their bones from either staying at depth for too long, or from staying in shallow waters, pinned down by predators. Researchers are busily trying to find out which.

A characteristic of prostate cancer cells is often over-activity of the androgen receptor (AR) that triggers cell division.
AR relies on interactions with several other proteins, such as HSP90 and p23, which help fold it into its active form.
It was previously believed that HSP90 and p23 rely on each other to work, but since then, resistance to HSP90 suppressors has led to research into lone p23 activity.
This line of research has found that blocking p23 alone does decrease the activity of AR, and so can be used against prostate cancers.
Trials blocking p23 are currently being conducted in both prostate and breast cancers.

Pectoral sandpipers live at high latitudes, which means for some of the year, days go by without darkness.
These extended periods of light coincide with the breeding season, and so the species has evolved so that male pectoral sandpipers can go without sleep for multiple weeks at a time.
Less time spent sleeping means more time for breeding, and that is what researchers have seen:
"The tracker data showed that the most wakeful males interacted with more females than those that slept. Paternity tests showed that they sired more young."

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