Bird Flu, Bush, Evolution — and Us
The emergence of the new, highly virulent bird flu is just the latest example of how the microscopic world is constantly evolving into new forms that threaten to devastate the human population. The seriousness of the threat was underscored yesterday by President Bush's announcement of a new $7.1 billion national preparedness plan.
To fight off this threat, we need to understand everything we can about the influenza virus. But even if we succeed completely in defeating the flu today, the problem is not going away. Not only will flu pandemics continue, but also we never know when a new disease such as SARS or West Nile virus will appear.
To keep ahead of these diseases, we need to continue our scientific research, and we need to educate our citizens about what they can do both to protect themselves and to help control the spread of disease. The current assault on the teaching of evolution greatly undermines our efforts to do this, now and in the future. If we stop educating our children about science, our society runs the risk of losing many of the wonderful advances that make our lives better.
Why has the debate about evolution re-emerged? Perhaps because few people see the obvious effects of evolution that geneticists and evolutionary biologists see every day.
Consider the influenza virus. Like many viruses, it mutates very fast, creating many slightly different strains that compete to see which ones can infect their host most efficiently. Each year, we create a new flu vaccine, which although not perfect, is very effective.
Why do we need a new vaccine every year? In a word, evolution. Each year, the flu accumulates many mutations, and some of those mutations allow it to avoid the existing vaccine. These resistant strains quickly take over — that's what Darwin meant by phrase "natural selection” — and become next year's flu strain. The same thing happens with bacteria, and this is why our over-use of antibiotics — in animal feed, hand soaps, and a growing number of other products — is hastening the evolution of frightening new antibiotic-resistant bacteria.
What about the feared bird flu, the H5N1 strain that has jumped from birds to humans and killed more than half the people it has infected? Most people do not understand that H5N1 is evolving not in people, but in birds. We do not yet know what genetic changes will turn this flu strain into a pandemic, but we do know that it will continue to evolve. Each time it jumps to humans, there's a chance that this one will be the new pandemic strain.
Scientists in my lab and others can tell you that developing a vaccine for the flu absolutely requires that we understand its evolution. We can also tell you that the flu does not "care” if we believe in evolution. It will keep evolving anyway, and it will kill us if we ignore it.
A major misconception about evolution is that it is a theory of the origin of life. It isn't. It is about the origin of species. It does not explain how life came to be in the first place, but rather it explains how, once life appeared, it separated into distinct forms that led to the wonderful diversity of life on our planet. (Darwin himself believed that the first life was put here by a divine being.)
The evidence for evolution is overwhelming and increases every year. Among the many astonishing things we have learned through the sequencing of the human genome is that we share hundreds of genes with the lowly E coli bacterium. These genes are so essential to life that their DNA has been preserved for two billion years, and today we can read the evidence in our genomes.
Several polls have reported that a majority of Americans believe that religion-based alternatives to evolution should be taught in science classes in our schools. These polls are called evidence that perhaps we should teach these alternative views. Reporters and pollsters deserve much of the blame here: Science is not like politics, where outcomes are determined by polls. Another recent poll revealed that less than half of the US population knows that the earth revolves around the sun. Does this mean we should teach that the sun revolves around the earth? What these polls do highlight, sadly, is the failure of science education. Of course it would be a huge mistake, and a disservice to our children, if we used polls to decide what to teach in school.
Let's drop the artificial debate about evolution and "intelligent design" and teach our children what science really is. Let's teach them that science requires a skeptical mind and that scientific theories must be supported by objective facts. If we want to teach children about scientific debates, let's pick a real debate — there are plenty of them — rather than an artificial one. And let's equip the next generation of scientists to bring us new cures and new technology, rather than burying our heads in the sand.
[Originally published in the Philadelphia Inquirer 2005 Nov 2 and reprinted with permission.]