Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How humans lost their scents

19.03.2003


In at least one type of endeavor, humans can’t even begin to compete with their best friends. Dogs can be trained to sniff out drugs and explosives or to track down a crime suspect by smell. Why can’t we do the same? Scientists from the Weizmann Institute of Science and the Max Planck Institute for Evolutionary Anthropology propose an explanation for this ancient quandary.



All mammals, including humans, have about 1,000 genes encoding smell-detecting proteins, or olfactory receptors. These receptors, located in the mucous lining of the nose, identify scents by binding to molecules of odorous substances. However, not all olfactory receptor genes are functioning in all species. It is the percentage of the working olfactory genes that determines the sharpness of smell in animals and humans.

In previous studies, the team of Prof. Doron Lancet of the Weizmann Institute’s Molecular Genetics Department discovered that more than half of these genes in humans contain a mutation that prevents them from working properly. In a new study, published in the March 18, 2003 Proceedings of the National Academy of Sciences (PNAS), the scientists tackled the next question: is the genetic "loss" a relatively old phenomenon affecting all primates, or did it occurr only in humans?


To resolve this issue, the researchers compared the DNA sequences of 50 olfactory receptor genes that are common to humans and different species of apes and monkeys. They found that 54 percent of the genes were impaired in humans, as opposed to only 28 to 36 percent in the other species. This research has made it possible to reconstruct this sense’s deterioration over the course of evolution: apparently, its decline took place within an "evolutionary moment" – only 3 to 5 million years– and occurred four times faster in the branch leading to humans compared to other primates.

The scientists conclude that the drop in the sharpness of smell is a purely Homo sapiens feature. It probably stemmed from the development of the brain in the human direction – a direction that entailed increased emphasis on vision, development of the ability to distinguish colors and the capacity to identify other members of the species by facial appearance rather than by smell.

The research team included Yoav Gilad, a Ph.D. student at the Weizmann Institute’s Feinberg Graduate School who conducted collaborative research at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, his adviser Prof. Doron Lancet, Weizmann graduate student Orna Man, and Prof. Svante Pöäbo, head of the Max Planck Institute in Leipzig.


Prof. Doron Lancet’s research is supported by the Crown Human Genome Center, Alfried Krupp von Bohlen und Halbach Foundation, the Avraham and Yehudit (Judy) Goldwasser Fund, Ms. Emilia Mosseri, London, Mr. James Klutznick, Chicago, IL, Kalman & Ida Wolens Foundation and the Jean-Jacques Brunschwig Memorial Fund.


Alex Smith | EurekAlert!
Further information:
http://www.weizmann.ac.il/

More articles from Life Sciences:

nachricht Chains of nanogold – forged with atomic precision
23.09.2016 | Suomen Akatemia (Academy of Finland)

nachricht Self-assembled nanostructures hit their target
23.09.2016 | King Abdullah University of Science and Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Chains of nanogold – forged with atomic precision

23.09.2016 | Life Sciences

New leukemia treatment offers hope

23.09.2016 | Health and Medicine

Self-assembled nanostructures hit their target

23.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>