WE ARE WHAT WE ARE, NOT WHAT WE WANT OR IMAGINE TO BE

We once again recall what Gilbert K. Chesterton already warned: "There will come a time when we will have to prove that the leaves of the trees are green." That time has come! 

 Geneticist Nettie Stevens (Cavendish (Vermont), July 7, 1861 - Baltimore, May 4, 1912) found that an egg fertilized by a sperm carrying a large chromosome ("X") produced a female and, conversely, if the sperm carried the small chromosome ("Y"), it would give rise to a male. The graphic illustrates -in human beings- the pair of sex chromosomes of men and women.