Body Hair

Apes, including humans, are physiologically riders, meaning that they carry their babies with them as opposed to leaving them in nests or dens because their breast milk composition is not suited to leaving their infants alone for long periods of time (Ross, 2001). But unlike humans, apes don’t need a tool to carry their infants in part because they have body hair for their infants to cling to but it’s more complicated than simply having body hair and a baby that can grasp it. Hair strength, density, infant weight, carrying position, adult posture, and even humidity play a part in successful infant carrying without tool use. Continue reading

What is the Obstetrical Dilemma? |Squished Pt 1|

In western culture, there is a long tradition of women suffering through labor… something about an apple? Throughout the history of obstetrics, theories have been tossed about to explain humanity’s apparently unique difficulties in childbirth. One of the more recent is the Obstetrical Dilemma which posits that the female pelvis is too narrow to give birth to human babies (without a lot of professional, technical intervention, and even then… ) but too wide (wider, on average, than a male pelvis) to be efficient.

Racist Roots with a side of Misogyny

The OD hypothesis came into being around the same time that hospital birth was becoming the norm in the United States. In 1949, Aldoph H. Schultz, from the John Hopkins University School of Medicine in Baltimore, Maryland published a paper titled Sex Differences in the Pelves of Primates about the pelvic measurements of a variety male and female cadavers from a selection of primate species. Among these non-human primate species are chimpanzees, gorillas, and negroes.

Yes, you read that correctly. And if you aren’t horrified, I am not sure I want you reading my blog. 

giphy

Schultz believed that black people represented a different species of primate, describing their pelvic measurements as more animalistic than whites, as a means of explaining why they had easier births. His research was used to justify the lack of medical care available to pregnant black women across the U.S. but even more so in the Jim Crow south. Continue reading

Big Babies

Humans, like the other Great Apes, are physiologically riders; breast milk composition is not suited to parking infants for long periods between feeding (Ross). For this reason among many others, our species has had to carry our babies with us wherever we go. Unfortunately, humans find carrying infants more difficult than our evolutionary cousins for three reasons: lack non-grasping feet and body hair, physically helpless infants and, most importantly for this post, the relative size of our infants.

giphy

Non-human apes in the taxonomic family Hominidae (literally means “Great Ape” and makes me think of Charlotte’s Web’s “Some Pig” but I digress) have smaller, more precocious babies than humans. Adult gorillas, for example, are significantly larger than adult humans, yenewborn and adult weightst their newborns are about half the size of human newborns. Chimpanzees, which are our closest extant evolutionary relative and have a similar adult body weight to us, give birth to newborns that are around 3% of their adult size, while humans have newborns that are around 6% of adult size (DeSilva). At what point since our common ancestor with chimpanzees, did hominins start having bigger babies? Continue reading