Photo: James St. John / Flickr
An international group of scientists revealed the cause of the mysterious fluctuations in biodiversity of ancient marine animals, which remained unexplained for many years. These fluctuations do not correspond to the typical picture of increasing species richness gives way to their subsequent disappearance. Instead, there are situations when the increase of biodiversity or the extinction is moderate. The results of the study publication reports Science Alert.
The researchers conducted a statistical analysis of the evolutionary dynamics of the various groups of extinct invertebrates and found that at the level of families and groups the balance between the appearance of species and the disappearance of remains. However, if we consider more different groups of animals, and the scale increase to classes and types, the dynamics becomes more complex.
In various families and groups of marine invertebrates will adapt to the environment in different ways, so there are curves with “thick tails.” According to scientists, the cause of such distributions may be that the animals have formed a niche conservatism, that is, they are adapted only to specific conditions.
Some scientists believe that mass extinctions occur on our planet every 26 to 30 million years, and the biodiversity replaced every 62 million years. However, not all groups of animals are subject to such dynamics. The results will help to understand the various processes that complicate the picture of evolution.
Video, photo All from Russia.