We understand that the infant sling would have been among the first tools our ancestors invented after bipedalism. Early infant carriers would have required fastening technology of some sort: knotting, weaving, or other means. Early infant slings, the kind A. africanus may have used, would most likely have been simple slings of animal tissue or plant material (Russell, 47). They may have resembled the ayĩ strap of the Amazon Kayapo or the forehead strap of the Jawara people.
These straps simply provided a place to balance the weight of the baby, requiring most support from the body of the adult. There is little protection from the elements for the baby with this kind of carrier: they would have full sun, rain, wind, and possibly branches or leaves of plants brushing against them.
When H. erectus left Africa (or, for some populations, evolved out of Africa), they expanded across Asia, into Indonesia. They may have even populated portions of Europe (fossil evidence is disputed as to species on this point). H. erectus used complex tools, used fire and cooked food, and living in small hunter-gatherer groups. They even created abstract art. What is significant is that they remained in warmer regions, environments that suited tropically adapted bodies.
H. heidelbergensis, however, expanded to northward, into modern day Siberia and northern Europe. Even during their time, those regions would have been cold. H. heidelbergensis would have required protective clothing. My hypothesis is that H. heidelbergensis developed sewing to produce protective clothing, or invented clothing using already known techniques for sewing– and this would have affected the kind of carriers their infants were transported in: either the clothing produced would have covered both adult and infant, or the infant would have to be put into a separate carrier that protected it’s body from the environment. Perhaps H. heidelbergensis’s infant carriers were similar to the Inuit Amauti, or perhaps they resembled the cradle-board of the Saami people of Norway.
Of course, we may never know what form ancient infant carriers took. What we can determine is that they were successful, allowing species like H. neanderthalensis to thrive in Europe for hundreds of thousands of years. Early humans, as they left Africa, encountered (and interbred) with these other groups *, learning about their infant carrier technology suited to new environments along the way– helping to ensure modern human’s survival.
* modern humans interbred with neanderthals (Sankararaman, et al.) and possibly others, however there is no evidence of this because we do not yet have genetic coding for them and cannot see what, if any, of their genetic markers are left in modern human populations.
Bourgeois, Catherine. Kayapo woman breastfeeding while holding machete. Digital image. Amazonia: Kayapo the Forgotten Tribe. Terresacree, 10 June 2005. Web. 23 Jan. 2015.
Russell, N. U. “Aspects of Baby Wrappings: Swaddling, Carrying and Wearing.” Ed. Susanna Harris and Laurence Douny. Wrapping and Unwrapping Material Culture: Archaeological and Anthropological Perspectives. Walnut Creek, CA: Left Coast, 2014. 43-58. Print.
Sankararaman, Sriram, Swapan Mallick, Michael Dannemann, Kay Prüfer, Janet Kelso, Svante Pääbo, Nick Patterson, and David Reich. “The Genomic Landscape of Neanderthal Ancestry in Present-day Humans.” Nature 507.7492 (2014): 354-57. Web. 24 Jan. 2015.