Cambrian explosion of life is still known as a major problem for paleontologists and geologists, when the earth entered the Cambrian, the species of life suddenly exploded and grew, starting from 530 million years ago, about 20 million years ago, many classes of arthropods, brachiopods, demodex, sponges, chordates, invertebrate fossils, etc. suddenly appeared, but in the early and more distant strata, there are still no fossils of their ancestors.
Therefore, the phenomenon of life species that suddenly appeared during this period was called the "Cambrian explosion of life" by paleontologists.
The Cambrian explosion of life has sufficient evidence in the strata to prove that the Chengjiang biological fossil group in Yunnan, the Burgess biological fossil group in Canada and the Kaili biological fossil group together constitute the world's three major Cambrian shale-type biological fossil groups.
Like nature, they magically reproduce the magnificent landscape of ancient marine life and the original characteristics of living animals, providing direct evidence for the study of the "Cambrian Explosion" with rich biological information. For example, the fossil biota of Chengjiang in Yunnan (a total of more than 120 species) belongs to more than ten species of animal phylums, such as sponges, coelenterates, brachiopods, gill-dragging animals, leafpods, software animals, arthropods, echinoderms, chordates, etc., in addition to some strange taxa with unknown taxonomic positions and a variety of symbiotic seaweeds.
These fossils have preserved the mineralized bones of many living species intact, and also preserved a large number of soft tissue marks, such as: epidermis, tentacles, cilia, eyes, intestines, stomach, digestive glands, mouth and nerves, etc., and even some animal digestive tract food can still be analyzed and identified.
Biologists have explored the primitive origins of arthropods, claws and crustaceans in invertebrates, and have confirmed that the phylum and subphylum of living animals and complex ecosystems almost originated in the early Cambrian period, causing evolutionary blows and providing evidence for explosive theories.
Why in the early Cambrian period, why the earth's living species will suddenly appear explosive growth is still a mystery, that is to say, this puzzle has not been systematically solved so far, but biologists have put forward various hypotheses, such as Chen Junyuan, a researcher in the field of archaeological biology in China, who once proposed the idea that cambrian biological mutations have a very obvious spontaneous evolutionary behavior, the hypothesis is that early Cambrian life species suddenly encountered a period of extremely suitable for survival, the earth's temperature, humidity, climate, Oxygen content and so on are very suitable for the survival of living species, so in different ecological environments, living species also evolve towards different morphological characteristics, and the phyla began to be complex and diverse, so the phenomenon of a large explosion of life species was presented.
There are also various hypotheses. Some believe that it is related to environmental changes caused by the impact of a celestial body on the Earth. Although this phenomenon was mentioned in Darwin's theory On the Origin of Species, it is also believed that the theory would be used as evidence to refute his theory of evolution. Although Cambrian species showed great explosions, the ancestors of these species of life may still be precambrian creatures. The "suddenness" of cambrian fossils and the lack of precambrian fossils are largely hypothetical due to incomplete geological records or to the submergence of old strata in the ocean.
Darwin's theory of evolution explained almost everything about biological evolution, but the Cambrian explosions have always made Darwin feel strange. Because Darwin's evolution also focused on finding the ancestral fossils of some organisms to judge the evolution of the species. However, some biological fossils found in the Cambrian period did not find the ancestors of the fossils of the creature before the Cambrian Period, which means that these creatures most likely appeared suddenly and did not follow a slow evolution. Darwin, in On the Origin of Species, also states that he cannot explain the sudden appearance of Cambrian fossils.
Traditional and classical biological theories still hold that biological evolution has undergone a long evolutionary process from aquatic to terrestrial, from simple to complex, from low to high, from survival of the fittest, which was gradually achieved through natural selection and the slow rolling of genetic variation, and that the Cambrian explosion event was not enough to challenge this evolutionary idea.
Xiaobian's conjecture is that it can evolve because of a specific environment or under the guidance of some forces.
In the future, xiaobian will also present a view that shakes Darwin's theory of evolution!!!