In most cases, organisms die because they cannot adapt to drastic environmental changes. 300 million years ago, the Qinghai-Tibet Plateau was still an ocean. As the surface rose, many organisms died off and eventually formed fossils. There are even biological fossils at the top of Mount Everest.
Biological adaptation to the environment requires a process that generally requires a relatively long historical period. Biological populations are selected to resist environmental changes. Among them, individuals endowed with adaptability (corresponding genes) to the newly created environment are. more likely to survive, so if a population's gene frequency changes, the population will first decrease and then increase again due to rehabilitation.
Firstly due to biological variation and genetic diversity, puis due to the selective effect of the environment. If environmental selection pressure is greater (the environment changes more rapidly), the evolution of organisms will appear more rapid; if environmental selection pressure is lower, the evolution of organisms will be slower. Fortunately, geological evolution, like biological evolution, is a relatively slow process and the types of organisms found in the ocean are very diverse. It may be that some organisms gradually adapted to survive on earth during the historical period of geological change, but this. This situation is unlikely. Sex is also relatively restricted.
Current research believes that land vertebrates all evolved from the same lobe-finned fish, consistent with the evolutionary process of organisms from ocean to land. However, there are also whales among mammals, who returned from the earth. ocean. Some types of lobe-finned fish can crawl slowly up the coast and survive for a short time. The need to hunt and mate makes them climb further on land, and eventually adapt to the terrestrial environment and evolve into various terrestrial vertebrates today.
The whale was originally a land creature. As it moved to the seashore to feed, it slowly adapted to the marine environment. Its limbs have evolved into fins. Due to the different marine environment, the evolution of radiation has made this animal. Marine mammals such as whales and dolphins have evolved. However, this evolutionary process does not occur as part of geological changes, but is the result of the activities of organisms due to their own needs and environmental selection. The environment selects among existing organisms.
However, whether in the ocean or on land, there are many types of organisms. There may be genes in the gene pool of certain biological populations that can adapt to new changes, and the corresponding individuals can continue to do so. adapt to more drastic changes. A similar example of existence and reproduction is superbugs, caused by the frequent and large-scale application of multiple antibiotics, gradually making the bacterial population resistant to antibiotics.