Bipedalism & Human Birth: The Obstetric Dilemma
Over hundreds of thousands of years, the human body has evolved in many different ways to help us adapt to our ever changing environment. The obstetric dilemma refers to changes in the female pelvic region as a result of our evolution towards bipedalism, and the resulting difficulties in childbirth. When assessing gestation periods, premature births and maternal & infant health, the question comes up as to why the human body has evolved in such a way as to make childbirth potentially fatal for both mother and child? The advantages of bipedalism can be seen when we throw a ball, carry the shopping bags from the car or collect the mail from the letterbox. But are the advantages we gain worth risking the lives of both mother and infant during childbirth? Have we found the balance between possessing bodily adaptations which are essential for bipedalism, and the advantages of having babies that are better developed and are born with larger, more complex brains? Bipedalism is a form of terrestrial locomotion, where humans and a few other bipedal creatures can move around using their two hind limbs. The earliest bipedal adaptation is thought to have begun with Australopithecines, dating back between 3 and 4.2 million years ago, with evidence of upright locomotion found in fossil form. A number of selective pressures started to arise with the evolution of the human species, and as a result a number of changes had to be made throughout the body, especially females, to accommodate for these pressures. Natural selection played a role in the development of bipedalism, as our ancestors were moving through environments that required them to have maximum foraging distance and ground coverage with minimal energy expenditure. This in turn meant that individuals possessing the right characteristics for upright striding had a greater chance of survival as their environments grew less and less accommodating. Among other...
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