May 24, 2019
“How can anybody in his right mind be against science?”
― Kurt Vonnegut, Cat's Cradle
On This Week’s Show
- A case of iterative evolution
- Sea otters are bouncing back
Science News with Amrita Sule, and JD
A Bizarre New Form Of Water Is Discovered
It’s been long known that ice exists in two solid forms – an
amorphous one and a more ordered crystalline one. Now scientists
have created a new form of water called the supersonic water/ice,
which exists in a solid and liquid state.
- Water molecules consist of two hydrogen atoms attached to
oxygen, which forms V shape. All these Vs can connect to form an
airy structure. When squeezed the oxygen and hydrogens shuffle
around to form other crystal structures.
- In order to make supersonic ice, scientists compressed water
between two diamonds by subjecting it to very very high pressure.
This squeezes the water into a type of ice known as ICE VII (60%
denser than normal water).
- This compressed water was then zapped with a pulse of laser –
heating it to thousands of degrees.
- Unlike the familiar ice found in your freezer or at the North
Pole, supersonic ice is black and hot. A cube of it would weigh
four times as much as a normal one.
- This kind of of water may not exist on earth, however might be
present in the mantles of the ice giants of our solar system
Neptune and Uranus.
- Lars G.M. Pettersson, a theoretical chemical physicist at
Stockholm University, said in the statement. “In a nutshell: Water
is not a complicated liquid, but two simple liquids with a
Living Example of Iterative Evolution
- Sediments from the Aldabra Atoll in the Indian Ocean show that
in the past it had been completely submerged by the ocean on
- It happened again ~136,000 years ago the Aldabra atoll was
reclaimed by the ocean, and that it virtually extirpated all the
terrestrial animals that lived there
- Including the Aldabra rail
- This research is from the University of Portsmouth and Natural
History Museum and published last week in the most recent edition
of Zoological Journal of the Linnean Society
- Tens of thousands of years later the Aldabra rail is back!
- What’s happening is an example of “iterative evolution:
- a rare process that involves the evolution of “similar or
parallel structures” from the same ancestral lineage, but at
- Hundreds of thousands of years ago white-throated rails flew
from their native home in Madagascar to the Aldabra atoll, part of
the Seychelle Islands.
- This atoll lacked predators, as is often the case in remote
- With no predators around they became flightless, and evolved
into a new subspecies, the Aldabra rail.
- The founding population still remained on Madagascar, these
- Madagascar, having predators, required that these birds have
- About 36,000 years after the Aldabra rails were wiped out by
the ocean an ice was happening
- Sea levels dropped and the atoll reappeared above the surface
of the waves
- Of course, the flightless Aldabra rails had been wiped out
- But then some more white-throated rails arrived from Madagascar
it seems, and that founding event occurred once again.
- Because the conditions on the atoll and selective pressures
were nearly the same, and the founding species was the same the
white-throated rails once again lost their ability to fly.
- This means that white-throated rails had colonizing populations
that evolved flightlessness twice! Iterative evolution.
- How do they know this?
- by comparing the bones of the ancient flightless Aldabra rails
— both those that existed before and after the flood — to more
recent birds. That includes the more modern bones of flying rails
and the flightless Aldabra rails (Dryolimnas cuvieri
aldabranus) that still live on the atoll today.
- Leader of the research Julian Hume said in a statement: “These
unique fossils provide irrefutable evidence that a member of the
rail family colonized the atoll, most likely from Madagascar, and
became flightless independently on each occasion.”
Live Science, IFLScience, Natural
History Museum, Smithsonian.com
Sea Otters Are Bouncing Back – And Into The Jaws Of
Great White Sharks
Conservation efforts to increase sea otter populations in parts
of the North Pacific have been successful. However, now it seems
they are becoming targets of great white sharks.
- Do Sharks like to savor otters??
- Not really! Sharks usually prefer more meaty sea lions or
seals. And these bites on otters appear to be more investigative
where they wind up with just fur in their mouths.
- These shark bites, even if the shark is just investigating,
often result in injuries fatal to the sea otters.
- Jerry Moxely and colleagues at the Monterey Bay Aquarium
started their investigation when growing numbers of dead bitten
otters were washed ashore.
- On compiling the data on seasonal movements of sharks they
found that sea otters were bitten more frequently in summer.
- It is around summer that the sharks venture close to the shore
and being low on fat reserves after their migration mistakenly
target otters and even humans.
- Moxely and colleagues observed that it was mostly the young
male otters that fell victim as they are more pioneering and tend
to venture in new territories.
- This could affect re-establishment of otters in such areas and
the otters may start seeking refuge from sharks in more protected
- A similar phenomenon was seen in Aleutian island in Alaska
where sea otters hid in shallow bays from orcas.
- Moxley says “By documenting when and where otters are most at
risk of shark bites,” says Moxley, “we can adjust rehabilitation
and release practices to support survival post-release.”
That concludes this episode of the Blue Streak Science
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This show is produced by the Blue Streak Science team, and
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Our hosts today were Amrita Sule, and me, JD Goodwin.
Thank you for joining us.
And remember…follow the science!