A team of researchers has recently discovered that new species of plankton have appear and disappeared over a period of 60 million years, long before human evolution. In analyzing the fossil record, it seems to them that astronomical cycles led to climatic effects that ultimately corresponded to the appearance and extinction of new plankton species on Earth.
Does the moving orbit of the Earth influence the evolution of life? It would seem so, indeed. “Our results show that known processes related to the mechanics of the solar system have shaped marine macro-evolutionary rates relatively early in the history of complex life,” write the authors in this new study published today in the Proceedings of the National Academy of Sciences.
The researchers examined in detail the data of 1,794 fossilized species of zooplankton, analyzing how they appeared and disappeared between 481 million and 419 million years ago. It seems that this information corresponds with those of the “Milankovitch cycles”, these regular changes in the shape of the Earth’s orbit around the Sun. They occur every 1.3 and 2.6 million years, and may have significant effects on the climate.
These “big cycles” would have modulated climate variability, alternating periods of relative stability in the environment with periods of maximum imbalance. They have influenced ocean circulation and structure, and thus phytoplankton populations at the base of the marine food pyramid. This is particularly the case of Graptoloid, a large group of Early Paleozoic zooplankton. These astronomical cycles could therefore explain the statistical changes in the number of new zooplankton species that have appear and disappeared.
It would be interesting to see if these cycles also affect a wider range of organisms, because it is not an exaggeration to think that cosmic forces can be the driving force for species renewal. Recall that last week, researchers speculated that the orbits of the planets Jupiter and Venus could have an influence on the climate of our planet, influencing the Earth’s orbit every 405,000 years. Read the story here.