Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Evolvability could be a driving force in drug resistance

10.08.2004


Not only has life evolved, but life has evolved to evolve.



That’s the conclusion drawn by two Rice University scientists who have designed a computer simulation to test the idea that evolvability -- the likelihood of genetic mutation -- is a trait that can itself be favored or disfavored through the process of natural selection.

The results of the study appear in the Aug. 10 issue of Proceedings of the National Academy of Sciences.


Researchers Michael Deem, the John W. Cox Professor of Bioengineering and professor of physics and astronomy, and David Earl, Deem’s post-doctoral research fellow, drew their conclusions from a sophisticated computer simulation that recorded how much and how rapidly proteins mutated based on external changes in their environment. As the researchers ramped up the frequency and severity of environmental changes -- imagine rapid shifts between heat waves and cold snaps or heavy rains and droughts -- they saw an increased likelihood of survival among proteins that mutated more frequently.

"Selection for evolvability would help explain a growing body of experimental results including the evolution of drug resistance in bacteria, the fact that some immune system cells mutate much more rapidly than other cells in our bodies, as well as why some bacteria and higher-order organisms have a tendency to transpose or swap relatively long sequences of DNA," said Deem.

Traditionally, a significant number of evolutionary biologists have discounted the idea that evolvability is subject to natural selection, in part because the idea that evolution acts upon the mechanism that causes evolution seems to violate the basic scientific principle that an event cannot precede its own cause.

But Deem and Earl argue that causal violations need not occur. For one thing, there are several different ways that genetic mutations occur. Random changes along the DNA chain are now understood to be only one way that organisms evolve. Mutations also occur based on genetic recombination, genetic transposition and horizontal gene transfer. With these mechanisms, relatively large chunks of genetic code are shuffled or substituted for one another along the DNA chain.

Deem and Earl’s argument centers on the idea that the ability to reorder genes or to cause large-scale genetic change are themselves genetic traits, traits that are subject to selection like any others.

The upshot of this is that many observations within evolutionary biology that were heretofore considered evolutionary happenstance or accidents, may in fact be explained by selection for evolvability.

Two primary examples of this can be found in the escalating "arms race" that has been documented between pathogens and the immune systems in people and other higher-order vertebrates. Deem and Earl argue that wide variation among bacteria and other antigens has put selective pressure on our immune systems to rapidly adapt methods of identifying and attacking invaders. Similar observations on the rapid mutability among flu viruses and other invading pathogens provide additional evidence, they said.

"The implication is that the drugs we have developed to fight invading pathogens also confer selective pressure on the evolvability of the pathogens themselves," Earl said. "In drug design, it is important to consider this and to look for ways to minimize or counteract this driving force for drug resistence."

Jade Boyd | EurekAlert!
Further information:
http://www.rice.edu

More articles from Health and Medicine:

nachricht How cancer metastasis happens: Researchers reveal a key mechanism
19.01.2018 | Weill Cornell Medicine

nachricht Researchers identify new way to unmask melanoma cells to the immune system
17.01.2018 | Duke University Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Optical Nanoscope Allows Imaging of Quantum Dots

Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.

Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Rutgers scientists discover 'Legos of life'

23.01.2018 | Life Sciences

Seabed mining could destroy ecosystems

23.01.2018 | Earth Sciences

Transportable laser

23.01.2018 | Physics and Astronomy

VideoLinks Science & Research
Overview of more VideoLinks >>>