For the third week running, chimpanzees are on my mind, as are the ways we humans construct similarities and differences between us and great apes. I’ve been thinking about how, for 20 years now, I’ve assigned in my Introduction to Biological Anthropology class Jane Goodall’s Through a Window-- and each year must offer a clarification.
Goodall brings chimpanzees at Gombe, Tanzania, alive in a way that’s especially effective for great-ape novices. Personalities emerge in her narrative, allowing students to think beyond “the great ape” or “the chimpanzee” or even “the Gombe chimpanzee,” to consider distinct individuals. The comparison between two mother-daughter pairs, Flo and Fifi, Passion and Pom, always generates discussion.
As Goodall fans know, famous Flo was a loving, nurturing Mom, emulated by Fifi in her own patterns of childcare as she grew up. Passion and Pom teamed up to become not so much famous as infamous, as they killed and ate other females’ offspring.
My students glean apt lessons from this contrast. Yet they come away assuming that mother-daughter bonds persist for life in chimpanzees—until the mother gets old and dies. This assumption is wrong; in the vast majority of cases at Gombe and other sites across Africa, chimpanzee females transfer at puberty into a new community, where they take up residence, mate, and rear their youngsters. Because they do not return to their natal groups, the mother-daughter bond, at least in terms of physical proximity, is severed.
I’m suddenly thunderstruck by the potential emotional implications of this severing. It’s no random realization, either. My husband and I are taking Sarah, our daughter (and only child) to college for the first time on Monday night. Move-in is Tuesday, followed by a luncheon program organized by the honors program at James Madison University, to which Sarah has been admitted. Then a private goodbye as we leave Sarah in her dorm, to launch this exciting new phase of life.
What an impact this impending event is having on us, as it must have on many thousands of families annually. Let me make some stipulations at this point. I am confident that Sarah will thrive at James Madison University; she has travelled on her own before, and is well-prepared both academically and emotionally, thanks to her own talented and strong nature. Further, I am unworried for myself. When an acquaintance asked me in passing last week how I’ll cope with “the empty house” upon Sarah’s departure, her phrase jarred around in my brain. It’s not one that fits. My house won’t be empty—it will be filled with a good marriage, anthropology work that I love, books strewn everywhere that I can’t wait to read, not to mention numerous rescued cats, each one abundantly loved.
On the other hand, if someone feels they have to tell me, “oh you’ll be just fine!” I flare up a bit, wishing to say, “Yes, of course, but let me have my feelings,” because there’s going to be an unfillable hole. All these 17 years have brought me to a point that involves more than pride in Sarah as a caring, generous-hearted person, an honor student, and an All-State soprano whose singing brings me beauty. It’s that I will so miss those infinite but tiny moments with her of spontaneous laughter about people or animals or books or films; our ridiculous love of reality-TV travel shows, shared with her Dad; our mutually challenged attempts to compete with total lack of finesse in the Wii kayaking game; and our bits of chat, and sometimes quite a lot more than only chat, about what’s happening in her life and mine, shared as we come and go with our two busy schedules. (We have shared explosive mutual exasperation at times, too; neither Sarah nor I, I feel certain, would opt to relive her year 14, or some of our stand-offs about the P word, otherwise known as procrastination.)
That daily in-person thread of connection with all its soaring highs and lows? It seems impossible to me that it’s about to change in the ways it will. Even thinking about this as I write causes me to tear up. Well, let me not hide behind a euphemism--- it causes me to cry. I cry easily right now. This temporary fragility of mine is no doubt exacerbated by it’s having been a tumultuous summer in other ways, involving (as I wrote earlier in this space) my mother’s emergency surgery and long recovery, and our shared struggle to accept her “new normal” in terms of health and memory. This strange crying of mine will fade soon enough, and the tears anyway are not because I would change anything about Sarah’s leaving—I wouldn’t. I adored my college years and know that she will adore hers, and that our sharing will not disappear, just shift in nature.
Still, it’s harder than I’d ever thought possible to weather this transformation without the tear-spilling part.
What emotions may be connected to the transfer-at-adolescence in nonhuman primates? In chimpanzees, it’s the daughters who leave. In many monkeys, it’s the sons. In some primate species, it’s both sexes. It’s a natural occurrence, just as much as is the pattern of our sons and daughters leaving their first home. But how does it feel to the apes and monkeys? After all, these primates (to different degrees across species and individuals) plan ahead, remember the past, feel love and grief.
Do the emigrating adolescents carry memories with them of home? Do the moms (and other relatives) left behind feel sorrow? And it’s such a clean break, in nonhuman primates! No post-transfer posts, no long-distance communication. Maybe this is just one of those areas where chimpanzee and human emotional lives part ways.
When I write next week’s blog post, I’ll be on the other side of an event that feels to me right now pretty huge. See you there.
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Hominid females roamed while males waited: study
By Julie Steenhuysen
CHICAGO | Thu Jun 2, 2011 10:33am EDT
CHICAGO (Reuters) - Females from two hominid species that roamed the South African savannah more than a million years ago left their families and struck out on their own, while their male counterparts tended the home fires, an international team of researchers said on Wednesday.
The findings, published in the journal Nature, came from an analysis of traces of the isotope strontium that had built up in adult teeth from two extinct groups -- Australopithecus africanus and Paranthropus robustus.
Both Paranthropus robustus and Australopithecus africanus were part of a line of close human relatives known as australopithecines that included the Ethiopian fossil, Lucy, estimated to be some 3.2 million years old and regarded by many as the matriarch of modern humans.
To understand how these hominids used the landscape and formed social groups, the team, led by Sandi Copeland of Colorado University Boulder, turned to the ancient dental record.
Using a high-tech analysis known as laser ablation, the team zapped the hominid teeth with lasers to measure ratios of strontium, a naturally occurring element found in rocks and soils that is absorbed by plants and animals.
The team tested 19 teeth dating from roughly 2.7 to 1.7 million years ago from both Australopithecus africanus and Paranthropus robustus individuals from the Sterkfontein and Swartkans cave systems in South Africa.
The team found more than half of the smaller, female teeth came from outside the local area, but only about 10 percent of the male hominid teeth were from elsewhere.
That suggests that males likely grew up and died in the same area, Copeland said.
Copeland said the pattern in which the females left home in search of a mate is similar to chimpanzees and some groups of modern humans, in which a woman leaves her family to join her husband's household.
But it is different from most other primates -- including gorillas -- where the females stay with the group they are born into and the males move elsewhere.
"In any mammal group, including primates, where individuals live in groups, either the females or males must eventually leave their birth community. One of the important reasons for this is to prevent inbreeding," Copeland said.
"In most mammals, it is usually the males that leave their home community," she told a news briefing.
She said the findings were a bit of a surprise.
"We assumed more of the hominids would be from non-local areas since it is generally thought the evolution of bipedalism was due in part to allow individuals to range longer distances," Copeland said.
Such small home ranges suggest that bipedalism evolved for other reasons, she said