Are Humans Still Evolving?

Anybody who teaches human evolution is inevitably asked: Are we still evolving? The examples of lactose tolerance and duplication of the amylase gene show that selection has certainly acted within the last few thousand years. But what about right now? It’s hard to give a good answer. Certainly many types of selection that challenged our ancestors no longer apply: improvements in nutrition, sanitation, and medical care have done away with many diseases and conditions that killed our ancestor...

 Scientific Ignorance is Dangerous

I don't know to what extent ignorance of science and mathematics contributed to the decline of ancient Athens, but I know that the consequences of scientific illiteracy are far more dangerous in our time than in any that has come before. It's perilous and foolhardy for the average citizen to remain ignorant about global warming, say, or ozone depletion, air pollution, toxic and radioactive wastes, acid rain, topsoil erosion, tropical deforestation, exponential population growth. Jobs and wage...

 The Immune System VS Viruses

The immune system consists of white blood cells that come in about 10 million different types. Each type has a protein lock on it called an "antibody," which corresponds to a key carried by a bacterium called an "antigen." If a key enters that lock, the white cell starts multiplying ferociously in order to produce an army of white cells to gobble up the key-carrying invader, be it a flu virus, a tuberculosis bacterium, or even the cells of a transplanted heart. But the body has a problem. It ...