Friday, June 2, 2023

The bungling in the ‘design’ of the human species

We republish this article by Marcial Escudero, professor at the Department of Plant Biology and Ecology at the University of Seville, published in The Conversation on May 11, 2023.

He said Sigmund Freud that two scientific findings dramatically affected the psychology of the human being: that Earth is not the center of the universe and that we have only been on the face of the planet for a very small period of all the time that has elapsed since his formation, 4 500 million years ago. Everything existed without us.

But one more bump must be added: we are not perfect, our species is far from being “designed” well.

The male reproductive system is an evolutionary hoax.

The male reproductive system is a clear example of how poorly designed we are. It doesn’t seem very smart or optimal to have such a sensitive organ fully exposed. It would be much better to have it well protected like the lungs or the heart.

The problem is that our male gametes, spermthey do not develop correctly at our body temperature (36.5ºC), and the solution to lower that temperature a bit has been the one we all know.

Other organisms, which are not warm-blooded, such as the Frogs, have the male reproductive organs well guarded and protected. Even in some warm-blooded organisms, such as the elephantsare safely stored without harming the male gametes.

back pain

The spine is undoubtedly another example of how badly designed we are. Who has not had in his life one or more back problems?

In the rest of the mammals that walk on all fours, the vertebrae are arranged horizontally, forming an arch, which efficiently supports the rest of the structures of the animal’s body.

However, in humans, our bipedal condition means that our vertebrae are literally arranged in a vertically arranged column. This arrangement means that the lower vertebrae have to support a great weight and various forces. And it is the reason that lumbar problems in our species are the rule and not the exception.

A blind spot in the eyes

He human eye it is also an example of evolutionary bungling. The retina is covered with photoreceptors that capture light information that the optic nerve subsequently sends to our brain. The problem is that at the point where the optic nerve crosses the retina there are no photoreceptors, which means that we all have a blind spot in each eye.

This is not the case in other species with eyes similar to ours, such as octopuses, since the camera-like eye has alternately generated twice in the course of evolution. In the eyes of the octopus The optic nerve fibers lie behind the retina, so they don’t need to pass through it at any point on their way to the brain, and octopuses, unlike us, have no blind spot.

throat and choking

Another of the most notorious examples of bad design of our body is that of the human throat. One of the first causes of unnatural death of healthy people in our species is choking. Last year in Spain Twice as many people died from choking that for car accident.

The tubes that carry food and air mix in a very dangerous way in some points of our body, and the pharynx is the most critical point.

Normally water and food travel from the outside to the esophagus and air to the trachea. But sometimes something goes wrong, and food goes into the windpipe, blocking the airflow, which can lead to fatal consequences such as death by suffocation. We are not well designed, for example, to eat grapes at high speed.

The Magellan expedition and vitamin C

Of the approximately 250 sailors who set out with Magellan and Elcano, only 18 completed the circumnavigation of the earth more than 500 years ago. One of the big problems during the voyage was scurvy, a disease that occurs after long periods of time without eating fresh food.

Not ingesting vitamin C causes its levels to drop and we cannot synthesize a protein, collagen, which is essential to maintain and regenerate many of our tissues. Our organism has vitamin C synthesis pathway, but it is incomplete. That explains why we can’t produce it and we have to consume it in fresh foods. Something that does not happen to cats, which are capable of synthesizing their own vitamin C, so they never suffer from scurvy.

Evolution and not intelligent design

These are just a few examples of unintelligent design in our body, but the list is long: the birth canalthe multitude of bones in relatively inflexible feet, the blood coagulation mechanism, nursemaid’s elbow, the human genome, etc.

We can very well explain our species as the result of evolutionary processes that are far from intelligent design. In it Homo sapiens The same forces have acted as in any other species that has existed or exists: natural selection, genetic drift, hybridizationetc.

We are the result of non-deterministic processes that occurred, but could not have occurred. And, it is felt, but we do not have a relevant role in the evolutionary process. On the contrary, we are, like so many other species, the result of chance.

The Conversation


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