Vice-presidential candidate Sarah Palin has spoken in favor of Creationism (or Intelligent Design), signaling that it's as important as ever to set the record straight on evolution. And coupled with global warming, habitat loss and other mounting pressures on ecosystems, understanding the role of evolution in biodiversity is critical - and an essential component of our K-12 education.

So what exactly is evolution? Well, in case your science teacher happened to skip that all-important section of the textbook (which many do), here's evolutionary theory in a nutshell. Random changes in genetic material (mutations) and competition for scarce resources can cause a species to change gradually over time. Eventually, new behavioral, morphological and physiological adaptations are reflected in the organisms' DNA, and a new species is generated. Such speciation, as scientists call it, takes a long time. In other words, an ape didn't magically transform into modern man over night - as many Creationists imply evolution to claim. In fact, it has taken man nearly 7 million years to evolve from the first hominids - which were a short species (less than 1.5 meters tall) that walked upright, had a protruding jaw, distinct eyebrow ridges and a small brain. 

So why is evolution only a theory? Well it is, and it isn't. New species arising by means of evolution is considered a fact (scientists can indeed demonstrate this), however, the mechanism by which evolution occurs remains theoretical. One of the world's most widely respected evolutionary biologists, Douglas J. Futuyma, can explain this a bit more eloquently:

The theory of evolution is a body of interconnected statements about natural selection and the other processes that are thought to cause evolution, just as the atomic theory of chemistry and the Newtonian theory of mechanics are bodies of statements that describe causes of chemical and physical phenomena. In contrast, the statement that organisms have descended with modifications from common ancestors--the historical reality of evolution--is not a theory. It is a fact, as fully as the fact of the earth's revolution about the sun. - Evolutionary Biology, 2nd ed., 1986

Indeed, the argument for evolution is strong, and the fact that it remains an afterthought or an intentionally avoided piece of the curriculum is nothing short of astonishing. Without a solid understanding of basic evolutionary principles (such as natural selection, adaptation and speciation), we are failing our children, who, in America, continue to lag behind in science literacy. Scientists and academics have clearly established evolution to be at the core of virtually all biological disciplines - ecology, microbiology, immunology and more. Pick up a peer-reviewed journal in any of these topics, and page through to find up to half of the research - if not more - conducted in the context of evolution. This generation of students makes up our future doctors, ecologists and microbiologists, and in order for them to be adequately prepared for undergraduate science curricula and research, it is essential that grade school biology be taught in the context of evolution. In fact, nearly every major university offers a program in Ecology and Evolutionary Biology, which is often an interdisciplinary department comprised of a wide breadth of academic subjects including biology, anthropology, chemistry, math and even English.

So if evolution is all over higher education, then why hasn't it trickled down to the K-12 curriculum? As long as the number of American adults who believe that humans did not evolve from an earlier species continues to rise (from 46% in 1990 to 54% in 2005), there seems to be little hope. But in spite of popular opinion, evolution has never been more important - or more relevant.

Scientists use evolution to understand a broad range of human health problems. It explains antimicrobial resistance, the possibility of the avian influenza virus to mutate into a human pandemic influenza virus and the emergence of novel pathogens that can infect plants, animals and humans. 

And as it turns out, evolution is even important as we study the impacts of global warming. Even as the Earth has warmed a humble one-half of one degree in the last 25 years, scientists have observed rare instances of warming-induced evolution already taking place. Remember that in order for evolution to occur, the gene frequency of a population must be altered. So an organism reproducing earlier or expanding its home range isn't necessarily an evolutionary indication unless it can be traced to a genetic shift in the population. Indeed, scientists have been able to identify a distinct genetic shift related to warming temperatures in more than a few situations. 

In 2006, an article (pdf) published in Science documents evolution in response to climate change. The authors describe how Blackcaps, a central European bird, are increasingly overwintering in Britain instead of Iberia. The warming-induced evolution of this species is demonstrated by a genetically distinct British subpopulation that arrives at the nest earlier and obtains better territories and mates, allowing for reproductive advantages. Likewise, another European bird, the great tit, has shown genetic variation in terms of which individuals are able to adjust their egg-laying date in response to the earlier, warming-induced maturation of their food source - caterpillars. Those that can adjust maintain the greatest reproductive success.

Scientists can still tell more stories of the observed occurrences of evolution caused by climate change. While it's fascinating to observe evolution in action, it's scary to consider how such a modest temperature change has already impacted biodiversity. Therefore, it's more important than ever to educate our kids - and us - about evolution and global warming. Both are central to understanding the dynamics of our biodiversity and, more importantly, what we can do to save it.

And one final note: is it possible to be Christian and a supporter of evolution? To the contrary of the Creationist claim, emphatically, yes! Many Christian denominations - including Catholicism - wholly accept evolution. That's not to say the story of Adam and Eve doesn't have significance. It having been divinely inspired and carefully constructed makes its allegorical power and significance much more meaningful than if it were simply a factual documentation of the events surrounding the creation of man. In my own humble beliefs, I like to think that a process so utterly perfect and creatively complex as evolution must be held in the hands of a higher power.