Life Sciences

Discovery and cognitive process of cells

This article focuses on "Who first proposed that cells are the basic unit of organisms?" and introduces the exchange of research on animal and plant cells between German botanist Schleidan and zoologist Schwang in 1838, establishing that cells are biological structures, functions, and reproductive units, forming the cell theory. This theory was listed by Engels as one of the three major discoveries in natural science in the 19th century.

This article introduces the process of continuous adjustment of the biological classification system with the development of cognition: from Linnai's two-boundary classification, to Haeckel's proposal that the protozoa realm should form three realms after the invention of the microscope, to Whitaker's five-boundary theory and Riedel's four-boundary adjustment, there is still controversy in the academic community in the 21st century about whether viruses are independently bounded, reflecting that the classification system is based on scientific understanding of biological evolution.

In the 18th century, Lin Nai and other scholars established a classification ladder centered on realm, phylum, class, order, family, genus, and species, making it clear that species are the basic unit.

This article focuses on the issue of whether mankind will die out, and mentions two serious biological extinction events in history: a large-scale lava explosion in Siberia 250 million years ago caused 95% biological destruction, and a near-Earth asteroid hit the earth 65 million years ago caused the extinction of dinosaurs; It also quoted Princeton University's Gott's calculation based on the Copernican principle, pointing out that there is a 95% probability that humans will become extinct between about 641025 and 97.5 million years ago, and believes that humans can survive for a long time.

There has been controversy over the evolution of humans for hundreds of years. Most scientists agree with Darwin's theory of evolution and believe that the ancestors of modern humans were Australopithecus, which is the best species in the genus Homo studied by scientists from many countries. Human evolution has gone through stages such as Australopithecus and Homo habilis, and adapting to the grassland environment such as upright walking has promoted evolution.

This paragraph explains how natural selection creates single-celled animals and plants. It mentions Darwin's point of view that 2.5 billion years ago, single-celled organisms in the primitive ocean showed two types of mutations due to lack of food and increased carbon dioxide. Natural selection won and multiplied, forming primitive single-celled animals and plants, amoebas, etc. or their descendants.

Natural selection is the core reason driving evolution.

This article discusses the emergence of eukaryotic cells, first explaining the differences between prokaryotic and eukaryotic cells, introducing the endosymbiosis hypothesis put forward by Margulis in the 1960s, and explaining that anaerobic cells absorb aerobic cells, autotrophic cells form mitochondria, chloroplasts, and ultimately constitute eukaryotic cells. The process also mentions the progress of artificial synthesis of living substances or helps answer the question of cell origin.

This article focuses on the world's first issue of cell origin. It mentions that in 2012, the American Discovery News revealed that the University of Oslo in Norway discovered the oldest single-celled organism 1 billion years ago. Combined with the chemical evolution hypothesis, it explains the formation process from small organic molecules to prokaryotic cells in the early earth, and related characteristics of modern cell membrane structure.

This article focuses on "Are life on earth forever unchanged?" and lists many facts about the changes of biological types over time, such as fossil records, living fossil examples, biological differences in the Galapagos Islands, and the evolution of domestic animals and plants from wild species., negates the view that life will never change in creationism, and mentions that there is no complete answer to the source of life.

Viruses have the characteristics of neither life nor life: Viruses are protein-wrapped nucleic acid complexes. They have no vital abilities such as metabolism, reproduction and genetic variation outside the cells, and are non-life; after entering cells, they can use host materials to metabolize and reproduce, appearing life characteristics, becoming a living body.