The author doesn't actually think this is the worst mistake evolution made. The articles in this series elaborate on ideas that didn't make it into a final book

The author doesn't actually think this is the worst mistake evolution made. The articles in this series elaborate on ideas that didn't make it into a final book. The author has some gripes with external testicles, but didn't find them important enough or interesting enough to fit the discussion about them into his book, Human Errors.