“There Is No Good Explanation”
A surgeon with 40 years of experience measured the jaw angle of two women presented as the same person. He found a 32-degree difference. He then ruled out every explanation medicine could offer.
The Statistics
The standard deviation for facial profile angle is approximately 4 degrees. The 32-degree difference between Lucy I and Lucy II represents 8 standard deviations — the outer extreme of what is biologically possible within a single individual.
The t-statistic for this measurement is 7.55. In peer-reviewed physics, a result above 5 is considered extraordinary.
Probability that these two profiles belong to the same person: less than 1 in 10 trillion.