Scientists at Vanderbilt University found that the world's first global extinction was caused by living organisms. This event, known as the Ediacaran mass extinction, happened 540 million years ago, when only bacteria lived on the planet. An article revealing the causes of the disaster was published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology.
The Ediacaran biota was characterized by great diversity. Bacteria spread throughout the Earth 600 million years ago, and their bodies were shaped like discs, quilts, tubes or bags. After about 60 million years, another form of life appeared on the planet - the first single-celled animals (Metazoa). According to scientists, they became environmental engineers who made the habitat unsuitable for the Ediacaran biota. It is the emergence of new organisms that is the main factor in global changes on the planet and mass extinction.
Paleontologists have found traces of a community of organisms, where the remains of both animals and Ediacaran fauna were present. The find was a testament to the close ecological connection between the two groups. Scientists believe that the ancestors of modern sea anemones and other ancient predators may have hunted creatures that prevailed on the planet before Metazoa. The researchers also draw an analogy between the influence on the biota of the first animals and people, which are changing the biosphere of the Earth at the present time. According to them, the Ediacaran extinction shows what happens when organisms arise that can radically rebuild ecosystems.
Another example of environmental engineers is the first photosynthetic bacteria that increased oxygen levels in the atmosphere. This led to the death of many anaerobic organisms.