日本研究小组拍摄的黑猩猩产子录像显示，这种动物的分娩方式与人类相似。科学家一度认为，人类的分娩方式是独一无二的。这一观点面临挑战。录像中，黑猩猩婴儿以面朝母亲的姿势从产道钻出。科学家一度认为现代人的灵长类祖先进化出这种姿势。这一研究发现反驳了一项理论。

为了进行此项研究，日本冈山林原大猿研究所的研究小组现场拍摄了3段黑猩猩产子录像。研究发现刊登在英国皇家学会《生物学快报》杂志上。为了拍摄产子录像，研究人员与圈养的黑猩猩一起生活，睡在它们的围栏内以确保分娩时自己就在现场。首席研究员平田智在接受英国广播公司(BBC)采访时表示：“我们一直与黑猩猩呆在一起。分娩时，我们就在屋里，近距离拍下整个分娩过程。”

科学家在研究论文中指出，猴子等灵长类动物的婴儿出生时面朝母亲。这允许母亲安全地举起婴儿，在其出生后快速清理呼吸通道。平田智说：“人类学家认为人类婴儿出生时面朝母亲是助产的需要，但我们的观察告诉我们事实并非如此。我们往往认为人类的分娩方式是独一无二的，但对于其他动物的分娩方式，我们的了解还不够。”

研究人员指出，3段黑猩猩产子录像反驳了这一理论。他们表示：“所有3次分娩过程中，婴儿钻出产道时的面部和肩膀方向均相似，说明这是一种‘正常’姿势，以同样的方式受黑猩猩的解剖学结构控制。”

原文出处：

Biol. Lett. Published online before print April 20, 2011, doi: 10.1098/rsbl.2011.0214

Mechanism of birth in chimpanzees: humans are not unique among primates

Satoshi Hirata*, Koki Fuwa, Keiko Sugama, Kiyo Kusunoki and Hideko Takeshita

Abstract

Researchers have argued that the process of human birth is unique among primates and mammals in that the infant emerges with its face oriented in the opposite direction from its mother (occiput anterior) and head rotation occurs in the birth canal. However, this notion of human uniqueness has not been substantiated, because there are few comparative studies of birth in non-human primates. This paper reports the mechanism of birth in chimpanzees (Pan troglodytes) based on the first clear, close-up video recordings of three chimpanzee births in captivity. In all three cases, the foetus emerged with an occiput anterior orientation, and the head and body rotated after the head had emerged. Therefore, these characteristics are not uniquely human. Furthermore, in two of the three cases, the chimpanzee newborns landed on the ground without being guided from the birth canal by the mother. The fact that the human newborn emerges with an occiput anterior orientation has thus far been taken as evidence for the necessity of midwifery in modern humans, but this view also needs revision. Our observations raise the need to reconsider the evolutionary scenario of human birth.