Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Birds do it. Bugs do it. But why don’t we?

17.06.2003


Many creatures including our fellow primates the New World Monkeys rely on highly specific scent molecules called pheromones to find a suitable mate. Even our humble mammal cousin, the mouse, was found to have 140 genes just for pheromone receptors when its genome was completely sequenced earlier this year.



But humans are clueless when it comes to pheromone signals, according to University of Michigan evolutionary biologist Jianzhi "George" Zhang. He believes color vision put our pheromones out of business.

Our closest relatives on the primate family tree rely on "sexual swelling" and gaudy, colorful patches of skin to signal their reproductive fitness and fertility, Zhang said. In fact, though humans and these apes still carry genes that should create pheromone receptors in our noses, these genes have mutated to the point that they are merely pseudogenes---they don’t function any more.


Zhang has used the genes of people and primates to get at the answer to this intriguing puzzle. Zhang (pronounced Zong), is an assistant professor in Ecology and Evolutionary Biology in the College of Literature, Science and Arts. Zhang’s paper on the topic appears this week in the online Proceedings of the National Academy of Sciences.

Zhang believes that a significant gene duplication made the difference and that it happened sometime between 23 million years ago and the split of the New World and Old World primates about 35 million years ago.

An ancestor of the Old World primates (humans, chimps, gorillas, orangutans, gibbons, baboons and guerezas) developed a second copy of the red/green color-vision gene, which resides on the X chromosome. Female New World monkeys have full color vision because females have two X chromosomes that harbor both red and green color vision genes. But males only have one X chromosome, so New World males have only one copy of either the red or green gene, and that leaves them color-blind. After the red/green gene duplication in the Old World family however, even the males got color vision too.

"Color vision made pheromones unnecessary," Zhang said. As a channel for sexual signaling, color vision works better at a distance than pheromones, Zhang believes. A pheromone attaches to a water molecule, drifts about in the air currents and finally lands on the proper receptor in someone else’s nose. The receiver can’t immediately be sure who sent it, where it came from or when. But with sexual swelling, everyone in the troop can see precisely when and where the signal is, even at a significant distance.

Sexual swelling occurs in about 10 percent of all primate species, but only in the Old World species of Africa and Asia, which is where humans probably originated, as well.

To test their idea, Zhang’s team zeroed in on a human gene called TRP2, which makes an ion channel that is unique to the pheromone signaling pathway. They found that in humans and Old World primates, this gene suffered a mutation just over 23 million years ago that rendered it dysfunctional. But because we could use color vision for mating, it didn’t hurt us. In turn, the pheromone receptor genes that rely on this ion channel fell into disuse, and in a random fashion, mutated to a dysfunctional state because they haven’t experienced any pressure from natural selection. Zhang calls this process "evolutionary deterioration."

Zhang’s paper, "Evolutionary deterioration of the vomeronasal pheromone transduction pathway in catarrrhine primates" appears in the Proceedings of the National Academy of Sciences online (http://www.pnas.org/cgi/doi/10.1073/pnas.1331721100)

Karl Leif Bates | EurekAlert!
Further information:
http://www.eeb.lsa.umich.edu/eebfacultydetails.asp?ID=96
http://www.hhmi.org/senses/d230.html
http://www.pnas.org/cgi/doi/10.1073/pnas.1331721100

More articles from Life Sciences:

nachricht The first genome of a coral reef fish
29.09.2016 | King Abdullah University of Science and Technology

nachricht New switch decides between genome repair and death of cells
27.09.2016 | University of Cologne - Universität zu Köln

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

 
Latest News

New Multiferroic Materials from Building Blocks

29.09.2016 | Materials Sciences

Silicon Fluorescent Material Developed Enabling Observations under a Bright “Biological Optical Window”

29.09.2016 | Materials Sciences

X-shape Bio-inspired Structures

29.09.2016 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>