HOME >> BIOLOGY >> NEWS
2-step process filters evolution of genes of human and chimpanzee

Although the human and chimpanzee genomes are distinguished by 35 million differences in individual DNA "letters," only about 50,000 of those differences alter the sequences of proteins. Of those 50,000 differences, an estimated 5,000 may have adaptive consequences in the evolutionary divergence between these two species, according to a study published in the March 6, 2007, issue of the Proceedings of the National Academy of Sciences.

Before such a new and beneficial mutation can take its place in the human genome it has to pass through a rigorous two-stepnegative and positivescreening process, say the study authors, evolutionary geneticists from the University of Chicago, the University of Tokyo and the University of Washington. Both steps focus on the most radical changes.

In step one, mutations, the genetic equivalent of typographical errors, are randomly introduced. When these mutations are still rare in the population, only strongly deleterious ones get weeded out through negative selection. The more radical mutations are more likely to be harmful and quickly removed. For those that are only slightly harmful, neutral or beneficial, the selective forces are weak and luck determines their fates.

In step two, a new mutation that has been fortunate enough to survive the initial elimination process, and confers some benefit, can then spread quickly through positive selection. The more radical the mutation, at this point, the faster it is likely to spread.

"We found that the same genetic changes that are unlikely to survive early negative selection are the ones that spread most quickly once they gain a foothold," said the studys senior author Chung-I Wu, Ph.D., professor of ecology and evolution at the University of Chicago. "To reach that conclusion, we needed to decouple the two steps of evolution and classify mutations into many different kinds."

The researchers used the very large survey of human ge
'"/>

Contact: John Easton
john.easton@uchospitals.edu
773-702-6241
University of Chicago Medical Center
5-Mar-2007


Page: 1 2 3

Related biology news :

1. Hepatitis C helicase unwinds DNA in a spring-loaded, 3-step process
2. N.C. A&T food scientist develops process for allergen-free peanuts
3. The UAB heads a European research project on proteases and pathological processes
4. Herpes virus hijacks DNA repair process
5. Molecular motors may speed nutrient processing
6. Study shows response to financial loss parallels brains processing of pain
7. A rainbow of methods promises insights into biological processes and diseases
8. Cancer scientists create human leukemia process to map how disease begins, progresses
9. Information processing in the central nervous system: the signalling system controlling movement
10. UCLA identifies new molecule involved in the bodys processing of dietary fat
11. Newly discovered platform for processing dietary fat

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:5/3/2016)... , May 3, 2016  Neurotechnology, a ... the MegaMatcher Automated Biometric Identification System (ABIS) ... large-scale multi-biometric projects. MegaMatcher ABIS can process multiple ... using any combination of fingerprint, face or iris ... MegaMatcher SDK and MegaMatcher Accelerator , ...
(Date:4/28/2016)... April 28, 2016 First quarter 2016:   ... 966% compared with the first quarter of 2015 The ... 589.1 M (loss: 18.8) and the operating margin was 40% (-13) ... Cash flow from operations was SEK 249.9 M (21.2) ... guidance is unchanged, SEK 7,000-8,500 M. The operating margin ...
(Date:4/26/2016)... Research and Markets has announced ... 2016-2020"  report to their offering.  , ,     (Logo: ... analysts forecast the global multimodal biometrics market to ... period 2016-2020.  Multimodal biometrics is being ... the healthcare, BFSI, transportation, automotive, and government for ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... June 27, 2016  Liquid Biotech ... funding of a Sponsored Research Agreement with The ... cells (CTCs) from cancer patients.  The funding will ... levels correlate with clinical outcomes in cancer patients ... will then be employed to support the design ...
(Date:6/24/2016)... ... , ... While the majority of commercial spectrophotometers and fluorometers use the z-dimension ... are higher end machines that use the more unconventional z-dimension of 20mm. Z-dimension ... bottom of the cuvette holder. , FireflySci has developed several Agilent flow cell ...
(Date:6/23/2016)... 23, 2016   Boston Biomedical , an ... designed to target cancer stemness pathways, announced that ... Orphan Drug Designation from the U.S. Food and ... cancer, including gastroesophageal junction (GEJ) cancer. Napabucasin is ... inhibit cancer stemness pathways by targeting STAT3, and ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... (Yeast and Mold) microbial test has received AOAC Research Institute approval 061601. , ... tests introduced last year,” stated Bob Salter, Vice President of Regulatory and Industrial ...
Breaking Biology Technology:
Cached News: