According to reports, since 2019, a team of scientists from The University of Stamblos in South America has been conducting scientific research on many tropical islands such as Mauritius Island, Durban, reunion Island, etc. Through a large number of data comparison and analysis, they have found a surprising fact: the toad that invaded the tropical island in the 1920s has shrunk by one-third in less than 100 years, which is a very incredible thing from the perspective of natural evolution of organisms.
Tropical island toads are rapidly getting smaller
Researchers say that there were no toads on these tropical islands, and between about 1922 and 1927, toads were artificially introduced on these tropical islands.
Over the past year or so, researchers have caught a total of 158 toads on the island of Mauritius for comparative studies, compared with 186 and 151 toads on Reunion Island and Durban.
The study found that the size of the toad on the island of Mauritius was the most obvious, of which the female toad on the island of Mauritius was 33.9% smaller than the toad in other regions, and the male toad, although the size change was not so serious, there was still a shrinkage.
The toads on Reunion Island, on the other hand, are 25.9% smaller than the female toads, and the male toad size does not change. In this regard, researchers are not clear about what is going on.
Because the toads on the islands of Mauritius and Reunion are both introduced from Durban in the same period, they belong to the same species as the toads in Durban, but due to changes in habitat, their size is completely different from the toads on Durban, which is not in line with the laws of evolution from the perspective of the biological evolution process currently mastered by humans.
Researchers say that in general, although animals on islands, because most of them are in a state of "isolation", affected by special climatic environments, will indeed evolve independently, but if it is a change in body size, it will take at least thousands of years, or even millions of years, to see the change.
But apparently, the toads on the islands of Mauritius and Reunion have violated this law, although the reason is not clear at present, but there are views that this may be related to the climate and environmental changes on the island.
Since mauritius and reunion islands have always been tropical climates, this has led to toads that originally bred seasonally in Durban, and now they can breed all year round, which makes them unable to store too much energy, and naturally they will not become very large or fat.
Considering that these changes are mainly concentrated in female toads, the researchers believe that this conjecture is likely to be the "standard answer", of course, the specific reasons for the change need further research to confirm.
Why are modern animals getting smaller?
In fact, it is not only the toads on tropical islands, in fact, many modern animals on the earth, even including plants, are getting smaller and smaller. You know, in the ancient period of the earth, there were many behemoths on the earth, for example, the largest dinosaur in the dinosaur era could be more than 40 meters long, and now the largest mammal elephant on the land, placed in the ancient period, can only be regarded as a normal animal.
What's going on? First of all, the first reason is the change in oxygen content in the Earth's atmosphere, in ancient times, the oxygen content on the earth once exceeded 30%, but now the oxygen content on the earth is only 21%.
We all know that modern scientific research shows that if the intake of oxygen is too much, it will lead to the growth of organisms, but now the oxygen content on the earth has become significantly less, and nature is accompanied by the evolution of organisms, and the size of living animals cannot be compared with ancient times.
In addition, today's earth's climate environment does not allow animals to become too big, because since the emergence of humans, the rise of human beings has gradually caused the earth's ecosystem to lose its balance, and at the same time, it has also led to fewer and fewer resources on the earth, and this resource reduction is mainly a change in the food chain for the earth's organisms.
For example, the reduction of forests, grasslands, etc., will lead to insufficient food sources for herbivores, naturally, they will not be able to develop very large, and they must also be vigilant against the killing of humans and other predators.
And the food chain we all know, it is interlocking, herbivores eat plants, correspondingly they are also carnivores food, when herbivores are getting smaller and smaller, natural carnivores will also change with their changes.
Some people believe that in the future, the creatures on the earth may become smaller and smaller, because only in this way will it be easier for them to obtain enough habitat and food, otherwise they will gradually be eliminated by nature.
Next, scientists are also ready to study the size changes of other organisms, see if all organisms are accelerating towards "small" changes, explore the relationship between their changes and humans, and look forward to solving the mystery as soon as possible.