Undeniable by Bill Nye Page B

How could nature or a deity cause so many forms to arise or be created? Did a creator imbue every seed with a soul? Expressing it in the words of the nineteenth century: How could what they called “homogeneity” become “heterogeneity”? Darwin’s descent by natural selection was a result of not only a great step in thought, but also the sidestepping of a great many ideas that missed the mark.
    A number of Darwin’s predecessors latched onto some aspects of natural selection without getting the fundamentals right. And nobody did a more spectacular job mixing correct and incorrect than Jean-Baptiste de Monet, who went by his courtly, inherited French noble name of Chevalier de Lamarck and is commonly called simply “Lamarck.”
    In mid-eighteenth-century France, Lamarck speculated that when animals and plants exercise certain organs, those that use other organs regularly and vigorously would not only enhance the function of said organs, but would pass on the tendency to have an improved or strengthened organ to their offspring. Apparently, he observed that blacksmiths had muscular arms and shoulders, as one might expect from a lifetime of hammering on anvils. He expected that a blacksmith’s kids would inherit those arms, passing along big shoulders, or perhaps the ability to develop big shoulders. From there, he drew a bigger conclusion about the bigger system in nature.
    It’s not hard to see why Lamarck thought that way. We are all familiar with people who follow in their mother’s or father’s footsteps. If you are the son of a blacksmith, you would grow up knowing more about metalworking than the average person. When you come of age and seek a trade, it’s reasonable that you’d have a leg (or a hammer) up on other would-be blacksmiths. It must have reinforced the conclusion in Lamarck’s mind. Today, there are a great many major league baseball players who are the sons of major league players. It probably has something to do with being exposed to baseball culture and the details of the rules in addition to inheriting the right physique for the game; but you can see how these factors working together might result in a son following in his father’s footsteps. You might think that the more you did something—the more you swung a bat or a hammer—the better you would get at it. Along with that you might conclude that the children of a horseshoer, a barrel maker, a bat swinger, or a ball thrower would tend to inherit these abilities. If that is true of people, why not animals as well?
    Seeking to link cause and effect, Lamarck speculated that this supposed ability to change or modify the traits passed on to offspring was the result of a complexifying force . If an animal wanted to eat certain leaves, for example, it might develop the right kind of teeth for it, and then pass that beneficial new trait to its offspring. This came to be called the inheritance of acquired traits. It would be a tendency or agent in nature that helps the successive generations build on beneficial modifications that resulted from a previous generation’s effort.
    Lamarck’s speculation was a helpful means to gain insight into the ways in which species change. He was grasping to understand the means by which an organism could gain complexity or specificity and efficacy as he, she, or it reproduces. For me, the iconic example is the giraffe ( Giraffa camelopardalis ). Imagine being a central European thinker and coming upon a giraffe for the first time; because of their unassuming ways and their seeming amicable outlook on life, giraffes are just fascinating. Inevitably you would wonder: How did they get those long necks? Why don’t they have regular necks like dogs, cats, and cows? After all, we do not observe giraffes actively stretching their own necks as they grow up. They are just born that way. If you cut the tail of a mouse, its offspring still have tails. If a