Evolution Talk

In 1865 Gregor Mendel pulled together his work on heredity in peas and produced a paper which he read to a group of his peers. Unfortunately for Mendel, the world would't be ready to listen until decades after his death.

In the last episode I asked the question 'Are we unique?' and then set about showing why it is we are not by looking at the animal kingdom. From tool use to altruism it appears that we are not as special as we might think. But, of all of earth's creatures we seem to be the only species cursed with the ability to ask 'why ?' We alone appear to have the ability to look back into the past to help us to explain the present and to prepare for the future. Is it, as Darwin said, only a matter of degree, or is it something more?

In what ways are we special or unique? Is it because we can think, like Rene Descartes said? Or is thinking just a chemical process that directs our actions as La Mettrie would have us believe? You might be shocked to know that we don't really know. Science hasn't been able to touch it.

If chimps are our closest relative why aren't we hairy like they are? The answer lies somewhere in the far distant past. Imagine how hot it must have been on the savannah after our ancestors left the safety of the trees to hunt for food. Homo Erectus did this almost 2 million years ago, and perhaps as recently as 70,000 years ago. They made their homes on the savannahs. They ran, played, and hunted. They fought for survival. And one of the byproducts of all of that activity is sweat. Wouldn't it be a benefit to have less hair?

Nestled comfortably within our DNA are a set of switches. Like the light switches you casually flip on and off in your home, they are responsible for making you who you are. And just like that one regulating switch which controls the current of electricity to your home, you have one which controls certain sets of genes. It's called the PAX gene.

We can make broad predictive strokes when it comes to how an organism will evolve. But that's all we can do. What those changes will look like, if they happen at all, is beyond our power to know. Does this mean that theories about evolution are outside of the realm of true science?

Every good story needs a villain. And there has been quite a few in the history of evolution theory. History has not been kind to Richard Owen. But just like the story of Dr Jekyll and Mr Hyde, Owen had his good side. Not that his good side cared about the proper treatment of his fellow man, his good side cared more about the proper treatment, and appreciation of, science.

In 2005 biologist Michael Skinner witnessed something that shouldn't have happened. His mice were exposed to a toxin. A toxin which caused the children of these mice to experience birth defects. This wasn't the surprise since the mice could easily have been exposed while in their mother's womb. This could explain the defects. What it couldn't explain was the fact that the next generation also had this defect.

If you've ever wondered why mice have been, and continue to be, science's favorite research tools it's becaus we are a lot a like. Yes, that little four legged furry bundle of whiskers and pink feet shares 99% of its genes with us. 75-80 million years ago that 99% was 100%. That was when our most recent common ancestor walked the earth. That ancestor split off into different directions. One lineage led to and the other led to mice.

In 2003 something was found in a large limestone cave located in Liang Bua, Flores. It was a small skull which was at first identified as being that of a small child. Upon further examination there was something odd about the skull. It didn't appear to be exactly what the researchers assumed it to be.