eLife Episode 44: Sperm Competitions and Ancient Horses

16 January 2018
Presented by Chris Smith.

In this episode, we hear about self-esteem, a new genus of extinct horse, the future of biological engineering, tracking mosquitoes with mobile phones, and how a love rival causes salmon to increase their sperm speed...

In this episode

Mobile phones can identify mosquitoes by the sounds of their wingbeats

00:32 - Mobile phones identify mosquitoes

Mobile phones can identify mosquitoes by recording the sounds of their wingbeats

Mobile phones identify mosquitoes
with Manu Prakash, Stanford University

As the vectors that transmit malaria, dengue, yellow fever, zika and a host of other infections, mosquitoes are widely regarded as one of the world's most dangerous animals. Yet we know very little about where they are, how they are spreading, and how their distributions influence disease. Now mobile phones may be coming to the rescue. From Stanford University, Manu Prakash...

Self-esteem is represented in the ventromedial prefrontal cortex and dynamically updated when people learn how others value them

06:31 - How brains measure self-esteem

Negative feedback is bad for our self-esteem, especially when it is unexpected.

How brains measure self-esteem
with Geert-Jan Will, Leiden University

How we feel about ourselves is largely dictated by what we think other people think of us. But just as important as someone else’s opinion is what we expect them to think of us. If we believe that someone should rate us highly and, in fact, they don’t, the dent to our confidence is much greater than a bad rating from someone we expect to mark us down. And Leiden University’s Geert-Jahn Will has identified where in the brain this happens…

Salmon swimming upstream to mate

12:29 - Salmon speed up sperm

Salmon increase the speed of their sperm when faced with competitors.

Salmon speed up sperm
with Patrice Rosegrave, Otago University, & Michael Bartlett, University of Canterbury

When animals compete for mates it’s usually the largest, strongest specimens that are successful and drive off the competition. But the underdog may have a hidden hand to play. Working on chinook salmon, Michael Bartlett and Patrice Rosengrave have found that less dominant males can compensate for being lower down the social pecking order by adding something to their seminal fluid that dramatically accelerates their sperm and boosts their chances of reproductive success…

DNA helix

17:50 - Biological existential risks

Horizon scanning has been used to identify 20 emerging issues in biological engineering.

Biological existential risks
with Christian Boehm, University of Cambridge

Researchers at the Centre for the study of existential risk, in Cambridge, given the rapid pace at which sciences like molecular biology are advancing, set out to identify the leading biological threats we are likely to face in the near future. Christian Boehm is one of the authors of the new report...

A family of stilt-legged equids (Haringtonhippus francisci) in Yukon, Canada during the last ice age.

22:49 - A new genus of extinct horse

DNA reveals the existence of a new, but now-extinct horse

A new genus of extinct horse
with Peter Heintzman, Tromso University Museum

Horses, zebras, asses and donkeys are all members of the group, or genus, called “Equus”. Their first ancestors arose millions of years ago. But as recently as a few tens of thousands of years ago there were two anatomically quite different groups of these animals alive side by side on Earth. One group - called the stout legged horses - are a close genetic match for all of the surviving horses around today. But the other group - called the stilt-legged horses - has since disappeared although it has a similar leg bone structure to certain family members that are still around today. Based on the anatomical similarities, palaeontologists had previously suggested that the extinct horses were related to today’s surviving species. Now a much more comprehensive genetic analysis using fossil DNA from stilt-legged specimens suggests that, instead, these stilt-legged horses were an entirely separate genus, which Peter Heintzman and his colleagues are dubbing Harringtonhippus...


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