The latest scientific research subverts cognition: the ultimate ancestor of mankind is actually this

There are often doubts about the theory of evolution on the Internet. When it comes to the process of human evolution, the most obvious criticism is: How can humans evolve from monkeys? Aren’t monkeys still monkeys, and aren’t humans still humans?

In fact, these people have completely misinterpreted the essence of the theory of evolution, which is that species evolve gradually from low to high, rather than a certain species suddenly changing into a new species. The theory of evolution has never said that humans evolved from monkeys, but it has gone through a long process of tens of millions of years, from mammals evolved primates, from primates evolved apes, and from apes evolved humans. Monkeys are just a close relative of humans.

Modern research suggests that the Earth was formed 4.5 billion years ago. At first, it was a hot, molten fireball, and life could not exist there. Hundreds of millions of years later, the Earth's surface cooled and condensed into a crust, and the atmosphere and hydrosphere were formed, and life gradually emerged. Evidence from geological archaeology shows that primitive life appeared at least 3.7 billion years ago, and science speculates that life may have been born 4 billion years ago.

The earliest life form was a single-celled organism with a cell form, so the original ancestor of all life was this single-celled organism. After billions of years of evolution, life differentiated into plants, animals, microorganisms, etc. After hundreds of years of exploration, analysis, research and modeling, scientists have formed the context of the evolution of life, which people call an evolutionary tree.

On this evolutionary tree, 95% of the animal family tree has a strong chain of evidence to support it, so it is consistent with reality, but there are still about 5% that are obviously inconsistent, which has puzzled scientists. This inconsistent part mainly points to the bottom of the animal evolutionary tree, that is, the ultimate ancestor problem.

Scientists divide the history of life evolution into two major stages, the Hadean Eon and the Phanerozoic Eon, based on whether life forms can be observed by the naked eye. From the birth of life about 4 billion years ago to the Cambrian period 542 million years ago, during this long historical period, life reproduced and evolved in the form of microorganisms, so it was invisible to the naked eye. This stage is called the Hadean Eon.

In the Cambrian period, due to changes in the earth's environment, life suddenly exploded and differentiated, and tangible creatures began to appear. The earliest fossil discovered by archaeology is Dickinsonia, which was 558 million years old. This seems to be a dividing line, demarcating the boundary between the Hadean Eon and the Phanerozoic Eon. From that point in time to the present, it belongs to the Phanerozoic Eon.

But the appearance of tangible animals should be earlier than this time, because the most primitive animals, although tangible, do not have real bones, and it is difficult to become fossils after death. It is difficult to find their traces in modern excavations. For example, sponges, anemones and comb jellyfish appeared about 600 to 700 million years ago, and their history is basically submerged in mud.

Fortunately, since the rise of genetics, scientists have been able to make the evolution of species clearer through gene comparison, which has opened up a way for research that was previously helpless. Because many ancient creatures still live in people's sight, by studying the genes of these primitive animals, we can find clues to their evolution.

But there is a misunderstanding that has misled people for decades. Scientists have always believed that the genetic evolution of species is from simple to complex. Based on this concept, they have concluded that sponges may be the earliest ancestors of animals.

The fundamental difference between animals and plants is "movement", which is scientifically defined as: belonging to a branch of organisms, generally feeding on organic matter, and being sentient organisms that can move or move autonomously. Sponges have existed in the ocean for 600 million years, with more than 10,000 species, accounting for one-fifteenth of the marine animal species, and are a huge family.

Sponges do not have mouths, digestive cavities, or central nervous systems, but they have many flagella in the small holes all over their bodies and a sieve-like ring. The flagella swing to absorb seawater, bringing in oxygen, bacteria, microalgae, and other organic debris, which are then filtered through the ring and become nutrients for the sponge to survive.

Therefore, sponges meet the basic characteristics of animals, but they are very low-level animals. According to the inherent concept that animals evolve from low to high levels, sponges have long been considered the starting ancestors of animals. However, from the perspective of genetic research, sponges have obvious inconsistent characteristics as the ultimate ancestors of animals.

As early as 2008, Yale University evolutionary biologist Cathy Dunn questioned this and believed that comb jellies might be animal ancestors that existed earlier than sponges. However, this view was not widely supported by the scientific community due to lack of evidence and has been controversial for decades.

The latest study, published in the journal Nature on May 17, supports Dunn's view with detailed genetic evidence. The study was conducted by a team of scientists from the University of California, Berkeley, the University of Vienna, the Monterey Bay Aquarium Research Institute and the University of California, Santa Cruz.

By studying the chromosome pattern breakage and fusion states at the bottom of the animal evolutionary tree, they finally discovered the relationship between these early animals from the chromosomes of single-celled close relatives of three animals, namely sponges, comb jellyfish, and jellyfish. They placed comb jellyfish at the bottom of the animal evolutionary tree, which is the ultimate ancestor of animals, thus eliminating the inconsistency of sponge as the ultimate ancestor.

Comb jellyfish, also known as comb jellies, are marine invertebrates that look like jellyfish. Their bodies are radially symmetrical and have eight rows of comb plates on their translucent bodies. The comb plates are covered with short cilia, which move constantly, but comb jellies are not good at swimming. They are just pushed by the current and drift with the current. Transparent comb jellies are almost invisible during the day and emit soft bioluminescence at night.

The scientific community has always believed that the genetic complexity of animals gradually increases during evolution. Therefore, sponges that lack neurons and muscles appear more primitive, while comb jellies that have muscles and neurons are considered to be an animal branch that is later than sponges.

This research breaks through past cognition and proves the complexity of the genetic evolution process, rather than a simple linear development. This breakthrough opens a new window for the future application of genetics in biological evolution research.

This study determined that the earliest animal ancestor that can be recognized since the division of life on Earth into plants and animals is the comb jelly. Humans evolved from the continuous evolution of animals, so the comb jelly can also be said to be the ultimate ancestor of humans. This conclusion may overturn the cognition of many people, especially those who scoff at the theory of evolution.

But science is science, and until there is new evidence to overturn the existing scientific conclusions, this is the truth. Are you willing to claim the comb jelly as your ancestor? Welcome to discuss.

This is an original article from Space-Time Communication. Please respect the author’s copyright. Thank you for your understanding and support.

References:

https://www.scientificamerican.com/article/the-closest-living-relative-of-the-first-animal-has-finally-been-found/?utm_sou rce=Nature+Briefing&utm_campaign=91a93ef166-briefing-dy-20230523&utm_medium=email&utm_term=0_c9dfd39373-91a93ef166-47042271