https://evolutionnews.org/2018/06/the-perfect-human-body/

The Perfect Human Body?
Jonathan Wells
June 26, 2018, 1:37 AM

We all know that the human body can suffer from flaws. For most people, that doesn’t mean our bodies are accidental by-products of unguided evolution. Instead, they are designed ― despite the fact that they sometimes start out flawed or become flawed as they grow older.

For English anatomist Alice Roberts, however, the human body is a “hodge-podge” of parts assembled in an “untidy” fashion “with no foresight” by evolution. So, like many evolutionary biologists before her, she set out with some colleagues to “design and build the Perfect Body.” Her results were aired on BBC Four on June 13, 2018.

According to Roberts, the Perfect Human Body would have ears like cats and lungs like birds. (Of course, bird lungs would require major modifications to other aspects of human anatomy, but the details might get “untidy.”)

The Perfect Human Body would also have legs like ostriches. Ostrich legs are “digitigrade” ― they rest on their toes. They are also very fast, enabling ostriches to run very quickly on the plains of Africa. And ostrich legs have proven to be a good model for making prosthetics to help people whose legs have been amputated above the knee.

Human legs are “plantigrade” ― they rest on their soles. They are not as good at running as digitigrade legs, but their stance is more stable and they are a lot more versatile. Would I trade mine for the equivalent of prosthetics worn by an amputee? Not unless I have to.

Another change Roberts would make is to the reproductive system. Because of the large size of a human baby’s head, giving birth can be dangerous and very painful for women ― though modern medicine has made it much safer and less painful. For Roberts, it would have been better if humans had evolved to be marsupials, like kangaroos, whose tiny fetuses crawl out into a pouch to complete their development.

But marsupials are much less intelligent than placental mammals (which include not only humans, but also sloths), because a marsupial brain “differs markedly in both structure and bulk” from a placental brain. So Roberts’s Perfect Human would be much less intelligent than an actual human being.
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Photo: The Perfect Human Body according to Alice Roberts, via BBC Four (screen shot).
https://evolutionnews.org/wp-content/uploads/2018/06/Alice-Roberts.jpg
動画
https://youtu.be/y1LdcagaqMc