Ask the Scientist: Dr. Marc Zimmer Answers
My research is on fundamental questions like, "What are the mechanisms by which genes evolved new functions hundreds of millions of years ago?" So, I don't really have a vested interest in any specific answer the way a scientist working in drug development might. Still, we always try to question our conclusions or preconceptions as rigorously as possible. We consider alternate explanations of our data, or imagine what the most skeptical critic of our results might say, and then think up an experiment that will determine which interpretation is correct. Science is always done by people who have their own personal and cultural perspectives, but what makes science special is that the data can often rule out what we thought or even hoped would be true.
I absolutely agree. One of the unfortunate costs of our society's "progress" is that we have released thousands of chemicals into the global environment that can alter our biology in profound ways. These chemicals are so widespread that they can't be cleaned up, and there's no way to avoid exposure to them. History has shown that the most effective way to deal with long-lived, hazardous chemicals is to stop making them and develop safer alternatives instead. That's what we need to do with the chemicals that disrupt the endocrine system.
We need an international agreement to stop producing these chemicals and use safer alternatives instead. There's been a lot of progress in this area already—radical reductions in the use of endocrine-disrupting pesticides, PVC plastic (which produces dioxin during its manufacture and disposal), and polycarbonate water bottles (which contain the endocrine disrupter bisphenol A) in countries that made this a priority. But there are also countries where less progress is made, and the use of some endocrine disrupting chemicals continues unabated. With an international agreement and a concerted effort by industry and governments, I think we could reduce the production and use of endocrine disrupters by perhaps 90% in just a decade.
The evidence that humans descend from common ancestors with other apes, other animals, and even plants, fungi, and bacteria is overwhelming. Every time another genome is sequenced, revealing common features that mark our shared ancestry with them, that evidence becomes even greater. In our lab, we resurrect genes that existed hundreds of millions of years ago in the earliest vertebrates—the common ancestor of you and a salmon, for example—to understand how the genes that run our bodies' endocrine systems evolved. But the life itself is well over 3 billion years old—an almost inconceivably long time. As more sequences are gathered, it will probably be possible to resurrect and study some of the genes from the common ancestor of all life on Earth and understand their functions. However, the very origin of life is shrouded in mystery. There are plausible scientific theories for how it happened, and experiments have shown that some of the chemical building blocks of life—mino acids in particular—can be generated under the conditions that prevailed on the young earth when life began. For now, our understanding of the origin of life is very murky—in great contrast to the clear evidence that once life on earth began, it produced the diverse life forms all around us by a process of descent from common ancestors and divergence under the influence of natural selection.