Navigation Links
Does evolution select for faster evolvers?

It's a mystery why the speed and complexity of evolution appear to increase with time. For example, the fossil record indicates that single-celled life first appeared about 3.5 billion years ago, and it then took about 2.5 billion more years for multi-cellular life to evolve. That leaves just a billion years or so for the evolution of the diverse menagerie of plants, mammals, insects, birds and other species that populate the earth.

New studies by Rice University scientists suggest a possible answer; the speed of evolution has increased over time because bacteria and viruses constantly exchange transposable chunks of DNA between species, thus making it possible for life forms to evolve faster than they would if they relied only on sexual selection or random genetic mutations.

"We have developed the first exact solution of a mathematical model of evolution that accounts for this cross-species genetic exchange," said Michael Deem, the John W. Cox Professor in Biochemical and Genetic Engineering and professor of physics and astronomy.

The research appears in the Jan. 29 issue of Physical Review Letters.

Past mathematical models of evolution have focused largely on how populations respond to point mutations ?random changes in single nucleotides on the DNA chain, or genome. A few theories have focused on recombination ?the process that occurs in sexual selection when the genetic sequences of parents are recombined.

Horizontal gene transfer (HGT) is a cross-species form of genetic transfer. It occurs when the DNA from one species is introduced into another. The idea was ridiculed when first proposed more than 50 years ago, but the advent of drug-resistant bacteria and subsequent discoveries, including the identification of a specialized protein that bacteria use to swap genes, has led to wide acceptance in recent years.

"We know that the majority of the DNA in the genomes of some animal and plant species ?including humans, mice, wheat and corn ?came from HGT insertions," Deem said. "For example, we can trace the development of the adaptive immune system in humans and other jointed vertebrates to an HGT insertion about 400 million years ago."

The new mathematical model developed by Deem and visiting professor Jeong-Man Park attempts to find out how HGT changes the overall dynamics of evolution. In comparison to existing models that account for only point mutations or sexual recombination, Deem and Park's model shows how HGT increases the rate of evolution by propagating favorable mutations across populations.

Deem described the importance of horizontal gene transfer in the work in a January 2007 cover story in the Physics Today, showing how HGT compliments the modular nature of genetic information, making it feasible to swap whole sets of genetic code ?like the genes that allow bacteria to defeat antibiotics.

"Life clearly evolved to store genetic information in a modular form, and to accept useful modules of genetic information from other species," Deem said.
'"/>

Source:Rice University


Related biology news :

1. Molecular biology fills gaps in knowledge of bat evolution
2. Same mutation aided evolution in many fish species, Stanford study finds
3. Researchers trace evolution to relatively simple genetic changes
4. Family trees of ancient bacteria reveal evolutionary moves
5. Great White shark evolution debate involves WSU Lake Campus geology professor
6. Revolutionary nanotechnology illuminates brain cells at work
7. The evolutionary triumph of flower power
8. MicroRNAs play a big part in gene regulation - and evolution
9. Enlisting genomics to understand flu evolution
10. Variation in HIVs ability to disable host defenses contributes to rapid evolution
11. Scientists track stealth DNA elements in primate evolution

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


(Date:5/20/2016)... -- VoiceIt is excited to announce its new marketing ... working together, VoiceIt and VoicePass will offer an ... slightly different approaches to voice biometrics, collaboration between ... Both companies ... "This marketing and technology partnership allows VoiceIt ...
(Date:5/12/2016)... DALLAS , May 12, 2016 ... has just published the overview results from the Q1 ... of the recent wave was consumers, receptivity to a ... wearables data with a health insurance company. ... choose to share," says Michael LaColla , CEO ...
(Date:5/3/2016)... , May 3, 2016  Neurotechnology, a provider ... MegaMatcher Automated Biometric Identification System (ABIS) , ... multi-biometric projects. MegaMatcher ABIS can process multiple complex ... any combination of fingerprint, face or iris biometrics. ... SDK and MegaMatcher Accelerator , which ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... WA (PRWEB) , ... June 23, 2016 , ... ... announces the release of its second eBook, “Clinical Trials Patient Recruitment and Retention ... recruitment and retention in this eBook by providing practical tips, tools, and strategies ...
(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)... 23, 2016 A person commits a crime, and ... to track the criminal down. An outbreak of ... Drug Administration (FDA) uses DNA evidence to track down the ... Sound far-fetched? It,s not. The FDA has increasingly used a ... of foodborne illnesses. Put as simply as possible, whole genome ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... and Mold) microbial test has received AOAC Research Institute approval 061601. , “This ... introduced last year,” stated Bob Salter, Vice President of Regulatory and Industrial Affairs. ...
Breaking Biology Technology: