Mx analyses were also repeated on two subgroups of twins stratified for age (equal or below 50 y and above 50 y). Very similar results were obtained in both groups (data not shown) so age at interview did not affect heritability estimates.. Archaeologist Ben Potter of the University of Alaska, Fairbanks, spends a lot of time visiting ancient sites of human habitation throughout the state. He says you can think of them like a laboratory to understand how humans coped “when they’re pushed to their
