>IMHO babies come with one biological mother, the one with the milk since we
>are mammals!  Therefore, any other parent, support person, GMa, Auntie etc.
>gets to care for our off spring with loving attention etc, etc...all the other
>baby/child care tasks that come with the baby....everything except
>breastfeeding (giving milk from the breast!).

Issues of lesbians aside, it is common in many cultures around the world for
babies to be nursed *primarily* by their birth mother, but also occasionally
by other females in the family such as grandmothers, co-wives, aunts, etc.
This is one of the many benefits of living in an extended family group with
multiple adult females in the household -- mom can go to the river to wash
clothes, or go to the field to plant or weed, or go to the market to buy
cloth, and she can leave the baby behind with someone who has milk to offer.
This has also been noted in a number of non-human animal species that live
in social groups.

Also, studies of "bonding" cross-culturally have shown that babies will bond
to any number of consistent caregivers.  If the baby is cared for primarily
by mother only, then it bonds to mother only; if the baby is cared for by
mother and grandmother both on a regular basis, it will bond to both; if the
baby is cared for by mother, grandmother, co-wife, aunt, older sister,
father, uncle, older brother, and neighbor on a regular basis, it will bond
to all of them.  The idea that a baby bonds *only* with its mother (or
parents) is a direct result of our isolated, nuclear family style of living
in the US and other Western countries.  The higher primates most closely
related to humans (gorillas, and chimpanzees) all live in multi-female,
multi-male groups.  Monogamous pair-bonded primates such as gibbons and
siamangs have no sexual dimorphism (no difference in size or appearance
between males and females).  Humans don't have as much sexual dimorphism as
chimpanzees and gorillas, but we have much more than gibbons and siamangs,
suggesting that humans are *not* designed to live in nuclear families with
monogamous pair bonds.

Katherine A. Dettwyler, Ph.D.
Associate Professor of Anthropology and Nutrition
Texas A&M University