Scientists use Darwin theory to create new technologies Scientists use Darwin theory to develop new technologies

As his 200th birthday nears, iconic theory still leaves its mark

Charles Darwin has become an indispensable tool for biologists to comprehend the natural world. Charles Darwin has become an indispensable tool for biologists to comprehend the natural world. Photo: AP Photo: AP Image 1 of / 1 Caption Close Scientists use Darwin theory to create new technologies 1 / 1 Back to Gallery

Still a flash point among fundamentalist Christians, the theory of evolution proposed by Charles Darwin 150 years ago has become an indispensable tool for biologists to comprehend the natural world.

Yet as scientists mark Darwin’s 200th birthday this month, evolution is no longer simply a narrative of life. Scientists have begun using it as a tool to develop new technologies.

By doing so, they have improved law enforcement, created smarter computer programs and are remaking the field of medicine. There have been quirkier applications, such as cleaner clothes, too.

Only recently, though, have scientists begun calling attention to these breakthroughs, as the ideas of the iconic English naturalist have faced renewed attacks.

In Texas, controversy over Darwin’s work resurfaced last month when the State Board of Education narrowly voted to delete a provision that required the teaching of the weaknesses and strengths of evolutionary theory. The board is toact soon on a proposal that would require students to consider the evolutionary principle that all organisms have a common ancestor. Supporters say they want children to understand there are viable alternatives to evolution.

But Andy Ellington, a University of Texas evolutionary biologist, called that argument “almost amusing.”

“You have these folks who are trying to suggest that we shouldn’t teach evolution as something our kids need to know,” he said. “But at the same time, there are these new technologies out there shaping our lives every day.”

Darwin, born Feb. 12, 1809, sailed from England in 1831 on a five-year voyage around the world. During the journey, he took copious notes about the variability of flora and fauna.

Darwin’s observations in A Naturalist’s Voyage Around the World eventually led to the notions of natural selection and evolution, theories he laid out in On the Origin of Species, the 150th anniversary of which comes in December.

Thanks to the discovery of DNA’s structure in 1953 and the mapping of the human genome half a century later, biologists now say they understand the mechanisms by which genes mutate and species evolve. And they’re using that knowledge in increasingly powerful ways.

One of the first and most well-known uses of evolutionary theory has come in law enforcement.

Among the 3 billion or so chemical bits, or letters, in human DNA are those that change slowly and those that mutate rapidly. Scientists realized that short segments of DNA vary greatly from person to person as a result. The finding gave rise to the concept of DNA fingerprints to identify individuals.

Crime-fighting, medicine

By the late 1980s, scientists were testifying in court about the reliability of DNA evidence to convict criminals. Such evidence has become a powerful forensic tool.

“It’s had a tremendous impact on criminal justice, not the least of which has been to free a lot of innocent people,” said Rusty Hardin, now a defense lawyer who in 1988 prosecuted the first Harris County case that used DNA evidence.

In recent years, the concept of genetic identification has been extended to such areas as vintage wines and Beluga caviar, where buyers want surety that what they’re buying is authentic.

Evolution also has helped scientists become smarter about the development and use of medicines such as antibiotics and vaccines.

Physicians now understand that bacteria mutate over time. When attacked by antibiotics, some bacteria become resistant to certain antibiotics and thrive.

“Evolutionary theory has definitely guided us, and now we as a medical community know to be much more careful about the use of antibiotics,” said Dr. James Versalovic, a Baylor College of Medicine professor and the director of microbiology at Texas Children’s Hospital.

The evolution of viruses also is critical to the development of vaccines. Some viruses, such as polio, have genetic material that changes slowly over time, allowing physicians to create a vaccine that will last for life.

Other viruses, including influenza and HIV, are constantly changing. This requires annual changes to the flu vaccine and has prevented development of a successful vaccine against HIV.

“We know we are in a world where we are in a constant competition with bacteria and viruses,” said Dan Graur, a University of Houston biologist. “We need to use evolutionary principles just to keep them under control.”

Some scientists also use evolution to develop drugs to combat disease, an approach called “directed evolution.”

Biologists employing this method generate a large batch of random segments of DNA — short strips of biological material — which are then tested to see whether any will perform a useful function inside cells, such as binding to a protein. The DNA segments that fail at the task are eliminated; those that succeed are copied in such a way that new mutations are introduced. These new variants then are tested. The process is replicated many times until an optimal sequence is found.

Computer programs

The approach has led to treatments for an eye disease called wet macular degeneration and other diseases, said Ellington, the UT-Austin biologist whose lab conducts directed evolution experiments.

Computer scientists use a similar process, called evolutionary or genetic algorithms. This technique involves many people writing computer programs for a certain task, such as managing air traffic or weather forecasting. Just as members of a species compete for resources in the wild, the programs compete with one another, mixing and matching lines of code and ultimately producing the most efficient algorithm for a certain task.

A company called Maxygen has applied this process to basic household goods.

Enzymes help speed up chemical reactions and are often good at digesting fats, starches and proteins — the kinds of materials that stain clothes. Maxygen collected enzymes from different bacteria, chopped and mixed them, and created new enzymes.

By randomly combining them over many generations, the company developed enzymes that improved detergents. Other companies have tried similar approaches.

“These kinds of applications are everywhere, and a lot of it began with Darwin,” Ellington said.

eric.berger@chron.com