Exactly What Is Evolution?

Abstract

Nobody knows what time of day it arrived nor from where it came, other than somewhere in outer space. After all, there was nobody here to see it. Perhaps some of the animals looked skyward and noticed it. Some may have fled in fear, finding a convenient hole to hide in or tree to hunker under. Some, depending on what kind of intelligence they may have had, might even have found themselves bewildered, having seen nothing like it before. Comet, planetoid, meteor? The words did not exist then, but some astral body figured to be 10 km—6 miles—across, roughly 65 million years ago, is thought by many scientists to have streaked over the sky and struck the earth in the shallow ocean near what is now the Yucatan Peninsula of Mexico, pulverizing itself in the gypsum substrate.