« Reply #21 on: Tuesday 02 January 18 17:17 GMT (UK) »
Many years ago, when I took a population statistics course, average human generation time was considered to be 28.5 years. That means, using definition #2 [difference in age between parent and offspring], that the average child is born when its mother is 28.5 years old.
Circa 1948 and I was a youngster in a classroom of 39 pupils learning about graphs and averages. We were told there were three generations per century. The lesson regarding averages required us each to give the age of our mothers when they married and I thought about lying about my mother's age because she was absolutely ancient compared to the other ages being quoted. My mother married the month after her 20th birthday, whereas most of my classmates mothers married when they were eighteen years old.
Aberdeen: Findlay-Shirras,McCarthy: MidLothian: Mason,Telford,Darling,Cruikshanks,Bennett,Sime, Bell: Lanarks:Crum, Brown, MacKenzie,Cameron, Glen, Millar; Ross: Urray:Mackenzie: Moray: Findlay; Marshall/Marischell: Perthshire: Brown Ferguson: Wales: McCarthy, Thomas: England: Almond, Askin, Dodson, Well(es). Harrison, Maw, McCarthy, Munford, Pye, Shearing, Smith, Smythe, Speight, Strike, Wallis/Wallace, Ward, Wells;Germany: Flamme,Ehlers, Bielstein, Germer, Mohlm, Reupke