An aquatic ancestor?

Did you catch Michael Phelps in the last Summer Olympics? He was like a fish, born for the water. 

Some thinkers are suggesting that maybe Phelps, along with all modern humans, world-class swimmers and hydrophobes alike, has a semi-aquatic ancestor.

Elaine Morgan, a writer who has been supporting this hypothesis for almost 40 years, and a small cohort of anthropologists and biologists are promoting the consideration of the aquatic ape hypothesis, a theory that suggests all modern humans have a semi-aquatic ancestor that sets us apart from chimpanzees.

Unlike other hypotheses about human life, like creationism and intelligent design, the aquatic ape hypothesis does not include divine intervention, and it is based on the theory of evolution. So why do some people think we have a semi-aquatic ancestor?

Morgan, the leading advocate of the aquatic theory, has drawn numerous connections between life in the water and the anatomical differences between chimpanzees and humans. Unlike chimpanzees, we have streamlined bodies that are highly hydrodynamic. Excluding diving mammals and diving birds, we are the only animals able to voluntarily and consciously control our breathing. This ability allows us to control our breathing for speech. Chimpanzees cannot talk because they do not have that ability.

Also, no matter how many waxing appointments we collectively need for this upcoming spring break, we are practically hairless compared to a chimpanzee. Interestingly enough, every other nearly hairless mammal, with one exception, is either aquatic, like the whale and dolphin, or has a fairly recent aquatic ancestor, like the elephant and rhino. The exception is the naked mole rat.

Our larger brains require nutrients that are most easily found in seafood. We humans also have downward facing nostrils and slight webbing between our fingers, both characteristics that would benefit us while swimming.

Many aspects of this theory seem to make a lot of sense, but many scientists have picked it apart and concluded it has little viability. They argue that most of the aquatic ape hypothesis claims have alternative explanations that do not include an aquatic ancestor. As a result, the theory has been almost ignored in college curricula.

Last semester, the College of Arts and Sciences offered a “themester” (a themed semester) on evolution, diversity and change. It was a great opportunity for students to begin thinking about what creates such great diversity among living things.

I encourage all students, no matter their field of study, to explore different theories and discoveries in the field of evolutionary biology.

Since the time of Darwin, people have studied evolution and made hypotheses about the origin of the diversity of living things on earth.

Use this semester as an opportunity to ask questions and research new ideas, and maybe you can decide if we really do have an aquatic ancestor swimming around in our history.


E-mail: kslabosk@indiana.edu