Last Ape Standing by Chip Walter (2013)

Science moves very fast these days, so I appreciate those rare writers who can make new developments comprehensible to my non-scientist brain. Chip Walter is one such, and he rather delightfully brings me pretty much up-to-date on paleoanthropology, the science of figuring out the human family tree and how we got this way.

Until we decoded DNA, there was very little we could say about our ancestors, because we had very few fossil samples, and the few bits and pieces we had were almost never intact bodies. OK, maybe the guy who was buried in peat moss and naturally mummified, and a few old pharaohs, but there were lots and lots of “missing links.” There was also very little to tell us when a given creature lived or how.

With the unraveling of the DNA code, we started looking at just how different we were from other apes, and then how similar. This led us to work out the start of our family tree. What has happened in the last 10 to 15 years has completely reshaped that tree.

For one thing, evolution is a very messy process, not simply a linear progression. A given alteration in our DNA may be beneficial in one way or one environment, detrimental under other circumstances. Or it can have almost no effect and simply be carried along until some other mutation makes it “turn on.” Then again, it might happen that several different bands of nomads each independently experienced changes, but later met and mated with another band, mixing up the DNA stew.

One of the most fascinating difference from the linear progression concept I learned as a child is that there were apparently as many as seven different human species alive at the same time, relatively recently. The DNA evidence suggests just how often the met and mated, which is to say which of them are still swimming around in our gene pool today. There’s probably a good reason I used to call my third husband “my little Neanderthal.”

Statements in this review do not necessarily express the thoughts or opinions of the Ethical Society of St. Louis or its leadership.