If Darwin were alive today, he would rethink "The Origin of Species"

Anyone who has seen the movie "Prometheus" will be impressed by a scene in the play: after those "engineers" (alien giants who created humans) drank a cup of black "liquid", their bodies immediately decomposed, and their DNA merged with the rivers and organic matter on the earth, and the DNA was recombined, and thus all kinds of life on earth were born.

Stills from the movie "Prometheus", from the Internet

The film conveys a basic message at the beginning: DNA can shape all kinds of life.

But for many people who have not been exposed to modern life sciences, such as Darwin himself, this is a very fresh perspective.

After all, Darwin's world of life is still far from what we know.

What's missing from Darwin's theory of evolution?

Darwin's Origin of Species holds a pivotal position in the history of life sciences. We have been taught since childhood that life can evolve. This is an important message of materialistic enlightenment.

However, if Darwin lived today, he would probably doubt the theory of evolution because in his research, evolution has no direction and everything depends on "God's will", which means that each species cannot control its own destiny.

Illustrations from the inside of Decoding 4 Billion Years of Life

Due to the limitation of the times, his view lacked evidence from genetics and paleontology, which made it impossible to explain the evolution of many organs of organisms. This was because Darwin had initially assumed a long transitional period for the evolution from one species to another - as long as time was long enough, the morphology of the species would eventually become what it is today.

This is why scientists have been keen to discover species around the world for a long time in order to supplement the connections between these organisms. However, the species that have been discovered at that time cannot help people find all the connections, so people are keen on discovering and studying fossils to find connections from the past.

But gradually, fossils could no longer meet the research needs.

From fossils to DNA, a new picture of the exploration of life

When fossil research progressed to the cellular level, and even the DNA level, people discovered that the origin of life seemed to have a new explanation:

Darwin did not understand DNA, nor did he understand how cells worked, let alone how genetic material built the body during embryonic development.

If we study the origin and evolution of life from the perspective of DNA, many of Darwin's views can be well confirmed and supplemented, but they will also be questioned or even overturned.

Because the discovery of DNA fully demonstrates that before individual life appears, all the information of life has been written and stored, and what life embodies is the life information in DNA.

For example, angels (if such creatures really exist) have wings, not because they suddenly grow wings out of thin air, but because the DNA for wings already exists in their cells. Similarly, when aquatic animals want to live on land, they do not evolve lungs only after they arrive on land, but because they already have the structure of lungs when they are in the water, which allows them to live on land.

Lungfish have both gills and lungs. When the dissolved oxygen in the water is insufficient, they use their lungs to breathe air, just like humans. Another type of fish has no lungs but has a swim bladder to increase buoyancy.

In DNA research, even if it is the same gene, different mutation locations can create different biological forms. For example, the body structures of fish, mice and humans are controlled by different versions of the same gene.

So people will pay attention to the embryonic morphology and find the differences in position from the morphology. For example, although the final morphology of sea squirts is very different from that of humans, they still retain the same characteristics as their vertebrate ancestors during embryonic development - a big head, and they propel their bodies forward by swinging their tails back and forth. In their bodies, a neural tube extends along the back, and there is a connective tissue rod (notochord) extending from the head to the tail; they even have gill slits behind their heads.

Development of sea cucumber sheath

The key to DNA opens the door to true evolution

In order to study the extent of the "transformative" effect of DNA on organisms, scientists have carried out many difficult experiments and produced some very interesting results.

One is the discovery of the NOTCH2NL gene.

A team in California compared brain organoids from humans and rhesus monkeys and catalogued all the differences.

In a dish, human brain organoids formed uniquely human cortical regions, while monkey brain organoids did not. The researchers studied the genes activated when the tissue formed. One gene was expressed in all human cells but not in monkey brain tissue. Although the name of this gene is a mouthful, NOTCH2NL, it is closely related to the story of human evolution.

The science fiction aspect of the research grew when the Dutch team took the human NOTCH2NL gene and inserted it into the genome of mice, creating a human-mouse chimera that grew more brain cells in the cerebral cortex, just like humans.

Image source: pixabay

One is that through the expression of dominant genes in corn, it was found that as long as the "jumping genes" are controlled, gene mutations can be controlled.

McClintock learned where and when mutations occurred within the corn plant, and she tracked the different colored spots on each kernel. She looked at the mutations on each kernel, and then repeated the observations on thousands of kernels in each ear of corn. She found that the color mutations could be turned on and off repeatedly. Ironically, because she was a woman, in a male-dominated era, her discovery of "jumping genes" was considered just "something weird about corn."

Image source: pixabay

It wasn’t until 1977 that other labs found evidence for jumping genes in bacteria and mice (in fact, in every organism they experimented with), and McClintock didn’t win the Nobel Prize in Physiology or Medicine until 1983.

These jumping genes can replicate themselves and insert themselves anywhere in the genome. As long as we take over these genes, we can achieve true "evolution".

The "gene mutations" that are often mentioned in reality are actually more mutations caused by the lack of genetic information. They have not become a better "evolution" for organisms to adapt to the environment, but often go further and further down the road of deterioration, so some strange organisms have become extinct.

In this way, the monsters in "Classic of Mountains and Seas" may have existed.

The code of life in salamanders

After a lot of hard experiments and multiple benchmarks, scientists finally made gratifying progress from salamanders, which have larger embryos and are easier to observe. More "keys to evolution" are hidden in these "cute creatures".

For example, salamanders create a variety of exaggerated organs and shapes by changing the speed of development during metamorphosis (stopping prematurely or slowing down).

For example, some salamanders can have 5-10 times more DNA than other species. Some salamanders and frogs have 25 times more genetic material than humans, which has led to the discovery of over-replicated "nonsense DNA" fragments.

Salamander chromosome paper cuttings have given new insights into genetic inventions in the history of life. Scientist Inui Ohno hypothesized that this redundancy means that one gene can remain unchanged to maintain its original function, while the other copy can change and acquire a new function. New genes can be created rapidly, at almost no cost to the producer.

In addition to the cute salamanders, there are many interesting experimental discoveries and stories: studying protein-encoding genes and molecular switches that control gene activity through the working mechanism of bacterial genomes, and many species evolving by losing characteristics (degeneration), etc., which is really eye-opening.

Life science is a science that is constantly evolving. In the early years, through the efforts of scientists such as Darwin, Huxley, and Hooker, the building of life science began to take shape. In today's era, it is biased to judge Darwin from an omnipotent perspective.

In such research, humans have also discovered life's hard work and desire to become stronger, which is also the greatest charm of life.

Part of this article is excerpted from "Decoding 4 Billion Years of Life History From Fossils to DNA"

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