What Evolution Is and Why You Need to Know

In This Chapter

^ Understanding what evolution is ^ Introducing the scientific field of evolutionary biology ^ Realizing why evolution is relevant

£ volution. You've no doubt heard about it, and you've probably seen a show or two about it on TV, but its significance likely escapes you. Watching a bunch of scientists on the Discovery Channel dig in the dirt with little toothbrushes and get really excited about some little bit of bone or a tooth may leave you thinking, "Well, yes, those do look like teeth, and they certainly do seem old, but . . ." A tooth, you say to yourself, is hardly reason to trade high fives and uncork champagne bottles. At times like these, evolution can seem pretty slippery. After all, there's got to be more to it than a stray fossilized tooth or bone fragment.

Well, there is. Evolution explains how we (and I'm using we collectively to mean all living organisms: you, me, and all other animals; moss, trees, and the roses in your garden; viruses, amoebas, bacteria, and all the other little critters) came to be in all our complexity and variation. The reason scientists get excited about fossilized teeth is because findings like these are consistent with what scientists understand about the evolution of life on Earth. That single tooth is just one piece of the evolutionary puzzle; thousands more pieces exist. All together, those pieces form a picture of our genetic past and a road map that leads from a common ancestor to who, and what, we are today. It's a journey over billions of years.

This chapter gives you an overview of evolution in all its glory: what it is, how it works, and what it does. By the end, you may begin to understand what the great evolutionary biologist Theodosius Dobzhansky meant when he wrote, "Nothing in biology makes sense except in the light of evolution."

0 0

Post a comment