Wednesday, September 3, 2014

Crickets in Hawaii Go Silent

Flatwing cricket )Teleogryllus oceanicus)
Some people might not like the chirping sound that crickets make. I love it (except in the middle of the night from under the bed). 

In Hawaii, happy chirping crickets (trying to attract mates) attracted parasitic, burrowing flies (Ormia ochracea) that preyed on them by listening for their sounds. 

University of Minnesota biologist, Marlene Zuk, Ph.D. has studied crickets in Kauai since 1991. Every year that she traveled to the islands offered fewer and fewer cricket calls until there was silence in 2003. 

It turns out the crickets hadn't disappeared, but simply evolved into stealth mode to survive the predatory flies. Original males that rubbed their wings together like a file on comb teeth to attract females were targeted by the flies, but new and improved males with newly mutated wings (without the file/teeth structures) were safe. The silent crickets flourished "under the radar" of the burrowing flies and grew in numbers.

The same thing happened on the island of Oahu roughly 3 years later in a case of independent evolutionary convergence. (Mother Nature catches on when she has a good thing!)

It looks like the strong, silent type of male is attractive in the cricket world, too.
Go science!

Friday, August 29, 2014

Summer Weather Extremes Explained

As the official end of summer draws near and we are experiencing rain in Little Rock, I thought this video on extreme weather was simple, informative and to the point. 

I know the Gulf Coast folks (friends/family in Houston and New Orleans) won't relax until November 1st (the end of the hurricane season), but that's another story. 

Happy Labor Day weekend, y'all. Go Science!

Monday, August 18, 2014

Interstellar Stardust and Its Absence

An international team of 23 scientists, has created maps (using data from 500,000 stars over a ten year period) of space materials located between the stars of the Milky Way. This material includes atoms and molecules left behind when a star dies, as well as building blocks for new stars and planets. The results published in the Aug. 15, 2014 issue of the journal Science may help astronomers solve a stardust puzzle that was first seen in 1922 in a graduate student's photographs of distant stars.

The research team focused on a strange feature in the light from stars; diffuse interstellar bands or "DIBs" (i.e., dark lines in the grad student's photographs). These visual and near-infrared spectra absorption lines seemed to show missing starlight as if something in the interstellar medium between Earth and the star was sucking up (not a technical term) the light. In fact, scientists have spotted more than 400 interstellar bands, but why the bands appear and their exact location are a mystery. 

Rosemary Wyse, a Johns Hopkins professor of physics and astronomy who played a major role in the research reports, "But we still don't know why stars form where they do. This study is giving us new clues about the interstellar medium out of which the stars form."

Finding the cause will allow researchers to better understand the physical conditions and chemistry of the space between stars and more on how stars and galaxies form. Go science!

Tuesday, August 5, 2014

A Brain Cell Tally

Have you ever heard or said, "Well, I lost a few brain cells with that one." But how many neurons do most people start with? Until one neuroscientist did the calculations, no one knew. Watch this talk (above) to find out why the human brain is so big compared to the size of our bodies compared to other species (a mouse has 86 billion neurons). 

Suzana Herculano-Houzel, Ph.D., Associate Professor, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro tackled the question of: Exactly how many cells are in our brains? Lots more than we should have given our size, but I won't spill the beans early. Check out the video. The answer to how humans can maintain such large brains is simple, yet elegant. Go science!