1. E

    Question Do haplogroup mutations usually just occur in only one, or a whole population of sperm cells inside the father's testes?

    I have been wondering about this for so long. Do those haplogroup mutations usually only occur in ONE of the father's sperm cells? So you can have two brothers in the same family carrying two different Y haplogroups, even if they are biological brothers by blood, both paternally and maternally...
  2. Jovialis

    'Old' sperm produces healthier offspring

    Sperm that live for longer before fertilising an egg produce healthier offspring—according to new research from the University of East Anglia and Uppsala University in Sweden. New research published today shows that longer-lived sperm in an ejaculate of a zebrafish male produce offspring with...