| |
Past Shows
November 26, 2005
 Listen to a Real Audio stream of the entire program (available Saturday, two hours after broadcast).
Download an MP3 of the entire program (22MB) (available Saturday, two hours after broadcast).
 Real Player is required to listen to RealAudio files. Other media players can play the MP3 or Ogg audio files.
Download the RealPlayer plug-in for your browser.
 CBC does not endorse and is not responsible for the content of external sites - links will open in a new window.
Searching for a "Gay Gene"
Listen to or download the mp3
or Ogg files.
(what's ogg?)
Is sexuality mapped out in our DNA?
|
Is sexuality a choice? It's a question that's plagued science and
society since the American Psychological Association stopped referring
to homosexuality as a disease in the early 1970s. There are those who
believe that parental and other societal influences can lead to a child
growing up gay. Others contend that sexuality is based in biology -- that
there are genes responsible for a person's sexual preference.
One of the first lines of evidence to support the idea that male
sexuality comes from our genes was from Dr. Simon LeVay, a former
researcher from The Salk Institute. He found regions of men's brains
that were different sizes in gay and straight men.
The research was controversial, and it was more than a decade before anyone
was able to confirm that Dr. LeVay's findings were due to differences in
biology and not behaviour. Dr. Chuck Roselli, a professor at The Oregon
Health and Sciences University, was looking at the brains of rams, and
found the same differences as Dr. LeVay.
Dr. Roselli's work further suggests this size difference is set
before birth, presumably by hormones. But hormones are influenced both
by the fetus and the mother. So the next step was to look for genes
that might be causing these hormonal changes. Dr. Brian Mustanski, from
the University of Illinois at Chicago, has identified three areas on the
chromosomes that he thinks contain genes related to sexual orientation.
In parallel, various researchers around the world have been looking at
the genetics of homosexuality using the fruit fly as an animal model.
According to Dr. Marla Sokolowski, from the University of Toronto, a
master switch gene for sexuality in flies has been found.
Overall, a picture of genes associated with homosexuality is starting
to emerge. It seems possible that these genes will be linked to
perception -- how we interact with the world around us. The next step will be to look at the influences on sexuality in women; an area that, while studied, has yet to uncover many clues.
Related Links
Guano-eating Salamanders
Listen to or download the mp3
or Ogg files.
(what's ogg?)
The Grotto salamander - Courtesy, Dante Fenolio
|
Grotto Salamanders live in caves that are, in many ways, ideal for
salamander life: they're cold, damp, and dark. On the other hand,
food is in short supply. While working as a graduate
student in Zoology at the University of Oklahoma, Dante Fenolio discovered that the Grotto makes up for the shortage in ordinary food by eating
surprisingly nutritious guano deposited by the bats who take shelter in
the cave.
Related Links
New Dino Species
Listen to or download the mp3
or Ogg files.
(what's ogg?)
Artist's rendition of Centrosaurus brinkmani - Courtesy, Mark Schultz
|
It's happened only a handful of times in the past few decades, so every time
a new dinosaur species is found in Alberta, it's pretty exciting.
Centrosaurus brinkmani is the name for the newly identified horned
dinosaur -- the first prehistoric beast in 30 years to be catalogued and
named, based on a complete skeleton from Dinosaur Provincial Park.
Dr. Michael Ryan is the Canadian paleontologist who identified
the horned dinosaur, which belonged to a group related to the
Triceratops. He's now curator of Vertebrate Paleontology at the
Cleveland Museum of Natural History. Brinkmani roamed in massive herds
about 76 million years ago. That's about 10 million years earlier
than Triceratops.
Related Links
Plants in Space
Listen to or download the mp3
or Ogg files.
(what's ogg?)
Modified plants from Dr. Boss' lab
|
If we ever seriously consider moving into space or onto another planet
like Mars, we're going to have to bring our plants with us.
Unfortunately, they'll be sensitive to the extreme temperatures, thin
air, lack of water and high radiation that will make human survival so
difficult. Two researchers from North Carolina State University -- plant
biologist Dr. Wendy Boss, and microbiologist Dr. Amy Grunden -- are trying
to give the plants a bit of an edge. They're moving genes from the hardiest life
forms on earth, microorganisms that thrive in boiling water, into plants
to help them survive in extremes of temperature.
Related Links
Question of the Week: Gas Clouds in Space
Listen to or download the mp3
or Ogg files.
(what's ogg?)
This week we have two questions about giant clouds in space.
The first is from John Pham in Mississauga, Ontario, who asks:
"I often see beautiful pictures of gas clouds in star-forming
regions. I'd like to know the average gas density of these clouds,
compared to our atmosphere."
The second comes from Don Wilmshurst, who asks: "If we could travel to
distant nebulae, is there a distance where, to the naked eye, the
nebulae would look like the colourful pictures taken from the Hubble
Telescope?"
For the answers, we go to the University of Manitoba where Dr. Jayanne
English is a professor of Physics and Astronomy.
Last week
|
|
