If humans disappeared, what species would rule the world?

Marina Fernandez Meteorized Argentina 7 min
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Evolution is a very difficult thing to predict. Credit: Luis DeLuca.

We know that life on Earth is possible as we know it thanks to several physico-chemical factors positively combined: the exact distance from our sun, the size of the earth, its gravity, the presence of water and a protective earth atmosphere with just the right density and an ideal composition rich in ozone and oxygen, among other.

The age of our planet is estimated at about 4.57 billion years, but initially life on it was not possible given the environment (temperature and type of atmosphere), which was totally incompatible with the evolution and evolution of biological molecules. According to research, it is estimated that about 3,850 million years ago, conditions on Earth began to be favorable for life on Earth.

Many animal and plant species have evolved, and others have disappeared in mass extinctions over geological epochs. In particular, the human species evolved from other non-human species, and to reconstruct our biological history, we need paleontology, biogeography, anthropology, molecular biology, and other sciences.

dominant species extinction humans dinosaurs water bears monkeys animals ants
The Fifth Great Extinction wiped out dinosaurs and 75% of all life on Earth 66 million years ago.

Our sun (currently a yellow dwarf star), will become a red giant in 5 billion years, increasing in size and brightness, and this relentless increase will end “life on earth.” But what if, for some reason, before our star dies, we humans disappeared before most of the creatures we know?

“dominant” species

Human extinction would cause fundamental changes in the Earth and its environment, as history has already shown us with other species. Many authors has compiled lists of candidate species to be the “new dominant species” (rats, cockroaches, dolphins, tardigrades, pigs, ants, whales, bats, etc.), with different selection criteria, but what do we mean by “dominant”?

Well, if we limit ourselves to the animal kingdom, the world has always been dominated by bacteria, even though the “age of bacteria” ended about 1.2 billion years ago, not because bacteria lost their dominance, but because we, humans, tend to classify large multicellular organisms as “dominant species”.

mass extinction dinosaurs monkeys ants water bears humans
Monkeys would not be the candidate species to become the new “dominant”, as they would be more likely to die out before us, or at least on par with us.

Our great narcissism causes us to designate ourselves as the dominant species, but we are not. Four out of five animals are nematodes (a type of microscopic worm), so it is more than clear from this example that that neither prevalence, quantity, nor diversity is essential for us to speak of “dominant life.”

Ecologists claim that without the presence of vertebrates (humans), the Earth is likely to thrive like never before after our extinction.

The human species has had such great success in this destructive conquest that many scientists think we are heading for the sixth great extinction (there have been five before, the last extinct dinosaurs and 75% of all life on Earth 66 million years ago).

planet of the Apes

You may remember the movie “Planet of the Apes”, where the new dominant species was assigned to our “close relatives”, suggests that primates could develop speech and adopt our technology if we give them enough time and space. But this possibility would not be the best, because it would be more likely that the apes would become extinct before us or at least on a par with us, because any crisis that wipes out humans would also be dangerous for organisms with similar basic physiological needs. . to the monkeys.

The new dominant species

According to the article published in The Conversation, Professor of Biological Sciences Luc Bussiere from the University of Stirling, Scotland, of all the species that have theoretically been dominant animals at one time or another, humans are the only ones with outstanding intelligence and manual dexterity.

It should be clear that evolution does not promote intelligence per se unless it leads to a higher level of survival and reproduction. It is therefore a serious mistake to think that our successors will be particularly intelligent, social, talkative, or tech-savvy beings.

So who will replace us as the dominant species? Although the answer is disappointing, we do not know exactly what they could be, but Bussière indicates that we can be pretty sure it will not be a chimpanzee speaks 50 million years after the extinction of man.

evolution evolution of humans future animals dinosaur water bear ant
Scottish geologist Dougal Dixon published the book “After Man: A Zoology of the Future” in 1981.

It is not excluded that the ants will regain dominion over the Earth, they have also been the subject of speculation in various analyzes, but it is impossible for us to know what these dominant ants will look like, descendants of modern ants.

Similarly, when Scottish geologist Dougal Dixon published his book “After Man: A Zoology of the Future” in 1981, in which he describes the dominant species of the future and shows illustrations of their possible morphology, these one and a half meter long bats could, for example, be a science fiction story for us today.

The fact is that in the light of history, for example, the small creatures that lived with the dinosaurs and managed to survive at the end of the Cretaceous were unlike any species known today. One thing all scientists agree on is that the development is very difficult to predict.

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