Resource: Evolving Ideas: Why Does Evolution Matter Now?

Siberia once seemed impossibly remote. Not anymore. A drug-resistant strain of tuberculosis (TB) from a Siberian prison has now been tracked to New York City. Using DNA fingerprints, microbiologists at the Public Health Research Institute in New York City have identified more than 12,000 different strains of TB from all over the world and are using this information to track the evolution of TB and its spread worldwide. But the strain they recently found in New York is different. It is one of the multi-drug-resistant strains from Russia that is very difficult to treat. Russian prisons have become breeding grounds for new multi-drug-resistant strains of TB because of crowded conditions, the use of low-quality antibiotics, and inadequate follow-up treatment for prisoners. At least 30,000 Russian inmates now have multi-drug-resistant TB.

A disease that had once been considered readily curable, TB has become a considerable foe. TB is on the rise worldwide and now rivals AIDS in the number of lives it claims -- between 2 and 3 million each year. That's why microbiologists Barry Kreiswirth and Alex Goldfarb of the Public Health Research Institute are focusing on Russian prisons. Kreiswirth says, "What's dramatically affected the spread of TB is our ability to travel. All the strains that are in the Russian prisons will eventually come to our doorstep." To meet this challenge head-on, Goldfarb has developed a pilot program in the Siberian prison system to change the way that TB is treated, with the hope of preventing the evolution and spread of additional strains of multi-drug-resistant TB.

TB is only the tip of the iceberg. Use and misuse of antibiotics, especially in the United States, has spurred the evolution of drug-resistant forms of pneumonia, gonorrhea, and other infectious diseases. Kreiswirth laments, "We've created this problem. Multi-drug resistance is a manmade problem.... By developing as many antibiotics as we have over the last 50 years, we've essentially accelerated an evolutionary process. The outcome is that we're going to have more drug-resistant microbes to the point where some of the most dangerous bacteria will not be treatable. We're racing against the microbe every day, and unfortunately we're losing."

One reason evolutionary theory is valuable is that it gives researchers a conceptual framework within which to form hypotheses that explain events in nature. Most of the time, evolutionary principles are used to explain past events, but the mechanism of natural selection has great power to explain events that are happening today. One of the most important of these is the evolution of antibiotic resistance in bacteria. Discuss how the conceptual framework of evolutionary theory is enabling medical researchers, not only to understand the evolution of multi-drug-resistant tuberculosis, but to devise treatments that have the best chances of preventing this kind of evolution.

Discuss how current practices involving the use of antibiotics in medicine and agriculture, along with the use of antibacterial substances in everything from dishwashing soap to mouthwash may be directing the evolution of bacteria that live in and around humans.

Discuss ways in which globalization has dramatically changed the nature of the environment in which human pathogens live. What consequences of this change does evolutionary theory enable you to predict?