Just before my trip to Minneapolis two weeks ago, I picked up the book Human Natures:  Genes, Cultures, and the Human Prospect, by Paul R. Ehrlich.  It took me a while to complete the book—mostly because I found myself reading a few pages and then putting the book down to ponder the information presented.  The book is delightfully well written and chock full of explanations that shed some light on things that I’ve wondered about for years, my post Are we still evolving? being a case in point.

The book begins with a layman’s introduction to genetic evolutionary theory, starting with a discussion of fruit fly evolution in polluted environments (deadly doses of DDT), and moving on to more complex organisms.  He then moves into a discussion of human genetic evolution, laying out the evidence that shows our genetic past, and explaining how different genetic traits have led to the modern human form.  He spends considerable time on the development of the human brain, which is undoubtedly one of the most fascinating products of genetic evolution.  All of this information is well presented, and backed up by copious notes and references.  And then the book turns from an interesting read to a very mind-opening experience.  It’s the examination of cultural evolution found in the last half of the book that begins to answer many questions, and ask many more.  There is enough stuff in the last 5 chapters alone to keep me pondering for years.  Perhaps what I like most about the book is the author’s willingness to admit (actually, propensity to point out) that many of the questions being asked simply cannot be answered by evolutionary theory.

The book has left me with a new appreciation of just how important is the role of culture in shaping the world and our perceptions of it.  It has also left me somewhat depressed, considering that much of what we call “human nature” is actually a product of centuries of cultural conditioning, and we could change some of our baser tendencies simply by changing our cultures.  Cultural evolution occurs very fast, and if our societies’ leaders would understand the role of culture in the shaping of human natures, we could make rapid positive progress in reshaping the world in which we live. 

The book’s relatively small size (531 pages, including 330 pages of text, 100 pages of notes, and 80 pages of references) belies its information content.  The author does a fantastic job of packing in the information while keeping the text readable.  Read this book.