Category Archives: Evolution

Q: How do we know that everyone has a common anecestor? How do we know that someone alive today will someday be a common ancestor to everyone?

The original question was: From biology and genetics we know that any group of living organisms had a mitochondrial most recent common ancestor (mitochondrial Eve): a female organism who lived in the past such that all organisms in this group … Continue reading

Posted in -- By the Physicist, Biology, Evolution, Probability | 3 Comments

Q: If the Sun pulls things directly toward it, then why does everything move in circles around it?

Physicist: Newton’s laws of motion say: Where MP and AP are the mass and acceleration of a planet, MS is the mass of the Sun, R is the distance between them, and G is a universal constant.  What this rather … Continue reading

Posted in -- By the Physicist, Astronomy, Evolution, Physics | 22 Comments

Q: If the number of ancestors you have doubles with each generation going back, you quickly get to a number bigger than the population of Earth. Does that mean we’re all a little inbred?

Physicist: In a word: yes.  But it’s not a problem in large populations. The original questioner pointed out that in the age of Charlemagne (more or less when everybody’s 40-greats grandfolk were living) the world population was between 200 and … Continue reading

Posted in -- By the Physicist, Biology, Evolution, Probability | 12 Comments

The nuptial effect

Every day, on average, 2-3 physicists get married.  On Saturday I’ll be attempting to push that average to as high as 3-4. So (for our regular readers), there’ll be a longer gap between posts than usual.  The future Mrs. Physicist … Continue reading

Posted in -- By the Physicist, Combinatorics, Evolution | 22 Comments

Q: Why doesn’t life and evolution violate the second law of thermodynamics? Don’t living things reverse entropy?

Physicist: In very short: nope. The second law of thermodynamics is sometimes (too succinctly) stated as “disorder increases over time”.  That statement seems to hold true, what with mountains wearing down, machines breaking, and the inevitable, crushing march of time.  … Continue reading

Posted in -- By the Physicist, Biology, Entropy/Information, Evolution | 68 Comments

Q: Is the final step in evolution an ascension into an energy-based lifeform?

Physicist: Awesome question!  The very short answer is: nope. Energy beings are an old staple of sci-fi (a good one), but they’re almost certainly impossible, or at least, it’s almost certainly impossible for life (as we know it) to evolve … Continue reading

Posted in -- By the Physicist, Biology, Evolution, Physics | 21 Comments