A while back, there was a debate in anthropology about “the importance of grandmothers” in the nuclear family.
“According to the “Grandmother Hypothesis,” post-menopausal women can increase their genetic contribution to future generations by increasing the survivorship of their grandchildren.
“A team led by biological anthropologist Leslie Knapp in the Department of Biological Anthropology (University of Cambridge) have discovered that a grandmother’s effect on grandchildren varies according to their X-chromosome relatedness.
“Specifically, maternal grandmothers have 25% X relatedness with both grandsons and granddaughters and both grandchildren are equally likely to inherit any one of her X-linked genes.
“Contrastingly, paternal grandmothers will pass on one of her X chromosomes to their granddaughters (making them 50% X-related) but she will not pass this chromosome on to her grandson (making them 0% X-related).
“The presence of a paternal grandmother had a harmful effect on grandsons because her presence was linked with an increase in mortality.
“Meanwhile, the paternal grandmother’s presence in her granddaughter’s early life had a beneficial effect in terms of the risk of mortality.”
//The presence of a paternal grandmother had a harmful effect on grandsons because her presence was linked with an increase in mortality.
Meanwhile, the paternal grandmothers presence in her granddaughters early life had a beneficial effect in terms of the risk of mortality.//
Hmmm. Interesting. But this part doesn’t make sense, on the face of it (ie, the grandma would protect either sex!!) Faulty conclusion? I’d like to read more, do you have a link?