Extinction promotes life diversification
In the fossil record, mass extinction may be the most striking pattern. This is an event that occurs all over the world and causes a large number of species, even species of the entire family, to disappear quickly in a short period of time. Such large-scale extinction events are usually triggered by some kind of global environmental disaster. They are so serious and happen so quickly that they can make the species disappear because they cannot evolve.
Large-scale volcanic eruptions led to the extinction of the Devonian, Permian, and Late Triassic; global cooling and intense glaciation led to the Ordovician-Siurian extinction; an asteroid caused The extinction of dinosaurs at the end of the Cretaceous is the five most concerned species extinction events, and their scale is the largest. But at the same time, there were many less serious events that still threatened civilization, such as the extinction before the end of the Permian.
These incidents are indescribably destructive. The impact of the Hicksulub asteroid on the Earth not only led to the end of the Cretaceous, but also stopped photosynthesis for several years, and made the world extremely cold for decades. It was a cold that no species could avoid, and it prevented most animal species from foraging in that darkness, causing them to become extinct one by one. At that time, perhaps 90% of the species disappeared in just a few years.
Then life began to recover, and they recovered quickly. Although this asteroid has eliminated 90% of mammalian species, they have stubbornly recovered and evolved into horses, whales, bats, and our primate ancestors within 300,000 years. Birds and fish have experienced similar rapid recovery and divergence. Many other creatures, such as snakes, tuna and swordfish, butterflies and ants, grass, orchids and aster, have also evolved or become diverse.
This pattern of recovery and diversification will appear after every mass extinction event. In the mass extinction event at the end of the Permian, mammal-like species were hit hard, but since then reptiles have prospered. When reptiles suffered a devastating disaster at the end of the Triassic, the earth was taken over by surviving dinosaurs, and they began to diversify. Although another mass extinction ended the dinosaurs completely, their initial evolution was all thanks to the mass extinction event.
Despite so much chaos, life has slowly diversified over the past 500 million years. In fact, there are several things that indicate that species extinctions have contributed to increased species diversity. First, the period of fastest growth in species diversity occurred after mass extinction. What is even more shocking is that the restoration of species is not only driven by the increase in species.
In the process of recovery, animals will continue to innovate in search of new ways of survival. They develop new habitats, new food, and new ways of moving. For example, after the end of the Devonian extinction event, the ancestors of fish climbed on land for the first time.
Extinction also promotes evolutionary innovation
Extinction not only promoted the process of species formation, but also promoted evolutionary innovation. The largest batch of innovative events in the history of life is the evolution of a large number of complex animals during the Cambrian explosion, which occurred after the extinction of the Ediacaran fauna, and this is no coincidence.
Innovation can increase the number of species that coexist because it allows species to enter a new niche instead of continuing to compete for resources in the old niche. Fish climbing on land will not compete with fish in the sea; bats that are sonared at night will not compete with birds that are active during the day. Innovation means that evolution is not a zero-sum game. Species can be diversified without extinction of other species.
But why does extinction drive innovation? Innovation may be hindered by a stable ecosystem. A modern wolf may be more dangerous than a velociraptor, but in the Cretaceous period, due to the existence of velociraptors, no small mammals could evolve into wolves. The evolution of any carnivore will end in a terrible ending, because mammals with poor adaptability will compete with or be eaten by velociraptors that have adapted well.
However, during the dormant period after species extinction, evolution may work for species with poor initial adaptability but long-term potential.
The extinction of the velociraptor gave mammals the freedom to explore new niche. At first, their predation ability was poor, but without dinosaurs competing with them or eating them, they did not need to have very superb survival skills, they just needed to be as good as other animals around them at that time. As a result, they thrive in an ecological vacuum and eventually evolve into large, fast, and intelligent hunting groups.
Destruction drives the creation of new things
Life is not only resilient, it can also thrive in adversity. Life can even recover from the current wave of extinction caused by humans. If we disappear tomorrow, then species will evolve to replace mammoths, dodos and passenger pigeons, and life may even become more diverse than before.
The idea that “extinction drives innovation” can even be applied to human history. The extinction of large animals in the Ice Age inevitably led to a substantial reduction in hunting and gathering belts, but at the same time it may also bring opportunities for development in agriculture. The Black Death brought endless suffering to mankind, but the dramatic changes in the political and economic systems at that time may have led to the Renaissance.
Economists talk about creative destruction, that is, creating a new order means destroying the old order. But evolution shows that there is another kind of creative destruction, that is, the destruction of the old system creates a vacuum, which actually promotes the creation of new things, and often better creations. When things are the worst, it is when the opportunities are greatest.