The history of biological development The earth where human beings live was formed about 4.6 billion years ago. In the long historical evolution, protein, a living substance, began to form on the earth. Primitive life forms-cyanobacteria and bacteria-appeared on the earth 3.8 billion years ago. 800 million years ago, multicellular metazoa appeared in the ocean, and by 545 million years ago, they almost represented all kinds of animals living today. From 430 million years ago to 4. 1 100 million years ago, plants and animals landed and evolved one after another, from which organisms radiated to every corner of the earth. The evolution of organisms has experienced a progressive development and evolution process from inorganic to organic, from low to high, from aquatic to terrestrial, which is irreversible. Today, there are all kinds of life on the earth, and nearly 2 million species have been described. If you add paleontological species, there are nearly 654.38 billion species that have appeared on the earth!
Organisms that lived in geological history (12000 years ago) are called paleontology, and their remains and remains are often preserved in the stratum in the form of fossils. Paleontologists know paleontology through the study of fossils, determine the genetic relationship between paleontology and modern biology through comparative study (see 3rd edition), and understand the living environment and palaeoecology of paleontology at that time through the study of the characteristics and conditions of fossil preservation, so as to guide the prospecting and exploration. At the same time, fossils can also help us roughly determine the age of strata. It should be pointed out that not all paleontologists can form fossils, only a very small part. Therefore, fossils are precious materials for studying the origin of life and biological evolution, and it is everyone's responsibility to protect these materials.
The evolution of organisms is closely related to the environment. Since the geological age, the surface environment has been constantly changing, and organisms have been evolving and developing in the process of adapting to environmental changes. By adapting to the environment, organisms produce characteristics of adapting to the environment (such as ichthyosaur-like body shape) in terms of body structure and function, and pass them on to future generations through genes, while organisms that cannot adapt to environmental changes will disappear. We call this phenomenon extinction. Extinction is the natural law of biological evolution. Human efforts can't save extinct creatures, but excessive encroachment and pollution on the environment will accelerate the extinction of endangered animals.
In the past 4.6 billion years, the earth and its crust have experienced a series of geological events such as life evolution, crustal movement, magmatic eruption, land-sea change, planetary collision, magnetic pole reversal and so on. These events constitute the history of the development and evolution of the earth and crust, and they are all recorded in rocks formed in different periods. We call layered rocks formed at a certain time in geological history strata. In fact, the stratum is a history book written by the earth itself, which records the development history of the earth: fossils preserved in different strata are records of life in different geological times; Different sedimentary rocks are records of different sedimentary environments; Different magmatic rocks are the result of magma intrusion and ejection at different depths underground; The contact relationship between strata is a record of the nature of crustal movement.