Page 28 - ARUBA TODAY

A28 SCIENCE
Monday 15 July 2019

Science Says:

In this Thursday, July 11, 2019 photo provided by Tim Tricky of the
band Hurricane Fall, emergency workers treat a passenger on
an Air Canada flight to Australia that was diverted and landed
at Daniel K. Inouye International Airport in Honolulu.
Associated Press
Airplane turbulence can In this photo provided by Kevin Bryant, a dominant male bluehead wrasse, upper left, defends

strike out of the blue its spawning territory and a group of females, yellow, off the coast of Florida. Associated Press

By MALCOLM RITTER lence is masses of air that Scientists get peek into how
AP Science Writer bob up and down in the
NEW YORK (AP) — atmosphere, somewhat some fish change sex as adults
They literally don’t see it like waves in the ocean.
coming. They can arise spontane- By JEREMY REHM are, feeding together and mostly dying female cells
“Clear-air turbulence,” ously or form as air flowing Associated Press occasionally mating. But and proliferation of early
which evidently jolted an over mountains is forced NEW YORK (AP) — If in the if a predator happens to male cells,” Todd said.
Air Canada flight Thursday upward, starting the up- beginning there was male snatch up the lead male, But hormones weren’t
over the Pacific Ocean, and-down cycle. and female, fish seem to the dominant female in the the only thing switching
strikes almost literally out Weather forecasters can’t have forgotten the memo. group will become a male. around. The scientists
of the blue, with no visible be much help in warning For nearly 500 fish species, “The sex change in this also saw a complete
warning in the sky ahead. pilots about where they’ll including the clownfish in species is remarkable rearrangement of
An aircraft’s radar can’t encounter clear-air turbu- “Finding Nemo,” the great because it’s so quick,” Todd chemical tags that attach
spot it coming either. lence, says Thomas Guinn, divide between sexes is said. It takes only minutes to to DNA. These tags turn
But passengers can cer- a meteorology professor at more like a murky line: If a few hours for the female’s genes on or off and have
tainly feel it. Some on the the Embry-Riddle Aeronau- circumstances call for it, behavior to become more specific arrangements in
Air Canada flight were tical University in Daytona the fish can swap their sex, territorial and aggressive males and females.
slammed against the ceil- Beach, Florida. with females turning into like a male. In a few days, As female wrasse
ing, and more than two Paul Williams of the Univer- males in some species and she courts other females. transitioned to a male,
dozen were taken to hospi- sity of Reading in England, males turning into females And after eight to 10 days, these tags were removed
tals after it made an emer- who is working on forecast- in others. she’s fully transitioned to a and reorganized, almost
gency landing in Honolulu. ing clear-air turbulence, People think of sex as being male. as if the fish was being
Clear-air turbulence hap- said some tests suggest fixed, said biologist Erica Todd and her team reprogrammed.
pens most often in or near that specialized radar-like Todd from the University removed the lead males “They’re sort of poised
the high-altitude rivers of devices could make the of Otago in New Zealand, from several wrasse groups and ready to go either
air called jet streams. The atmospheric disruptions vis- “but there are so many fish in the Florida Keys. As the direction” like a seesaw,
culprit is wind shear, which ible to pilots. that can push it in the other females changed sexes, she said. The hormones
is when two huge air mass- But the devices are ex- direction.” the researchers took DNA help push it to the male
es close to each other are pensive and very heavy, a Scientists have known for from cells in the animal’s side.
moving at different speeds. drawback for airplanes, so decades about the sex brains and genitals so they Laura Casas, a biologist
If the difference in speed they are not widely used. trades, but they’ve had could follow what was in Spain who was not
is big enough, the atmo- Once pilots hit a patch of limited understanding happening at the genetic involved in the study,
sphere can’t handle the turbulence, they can try of how the exchange level. called the results surprising.
strain, and it breaks into tur- to fly out of it, possibly by happens. In a study They found that removing She expects the findings
bulent patterns like eddies changing altitude, said published Wednesday in the males likely stressed can apply to other sex-
in water. Clint Balog, also of Embry- Science Advances, Todd females. The hormones changing fish, including
Another source of turbu- Riddle.q and her colleagues detail released from that stress her study animal clownfish,
the molecular events dial back the activity of which shift from male to
behind this ability, as well the gene that makes the female.
as what keeps mammals female hormone estrogen, Matthew Grober, of
stuck as one sex or another. and eventually ovary cells Georgia State University,
The researchers looked at start to die. At the same was more skeptical,
the bluehead wrasse, a time, those hormones especially of stress as the
reef fish that swims in small increase activity in the source that triggers the
groups of a dominant genes that produce male change. He questioned
blue-headed male and hormones, and later how the fish avoid
a posse of smaller yellow testicles form. changing sex from day-
females. Normally the male At a certain point, the to-day stress and suspects
and females stay as they reproductive gland “is something else is at play. q