Why there was a sudden diversification of species

Examples of the oldest fossils of shelled animals from the early Cambrian Period. Image: Lin Na

Researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have now confirmed the existing theories that extreme niche formation and tectonic plate movements are responsible for the development of the wide variety of species. Their findings have recently been published in the renowned journal PNAS*.

451 million years ago, an event took place that had a major influence on the evolution of life on earth. This event was the Cambrian explosion, which took place at the beginning of the Cambrian Period over a – from a geological point of view – relatively short period of 5 to 10 million years and saw the evolution of all of the major modern animal groups.

To find out what caused this event, researchers from FAU's Geozentrum Nordbayern evaluated a large database of fossils from the Cambrian Period. They analysed the biological diversity of all known species from this period on a local, regional and global level with the aim of understanding the ecological principles that led to the Cambrian explosion.

The causes? Niche formation and plate tectonics

'We discovered that while the number of species within local ecosystems increased in the early Cambrian Period, this was not the main reason for the evolution of the variety of species on a global level,' says Lin Na from FAU's Chair of Palaeoenvironmental Studies. Instead, the different evolution of different populations was much more important.

This is because as species adapted more and more to their environment their ecological niches became more restricted. This meant that individual populations evolved into new species that were adapted to their environments. Carnivores played an important role in this, as Prof. Dr. Wolfgang Kießling, Chair of Palaeoenvironmental Studies, explains.

'Carnivores kept populations small, preventing too much competition for resources. At the same time, however, they forced species to develop new ways of avoiding being eaten and increasingly sophisticated methods of getting food.'

This biological arms race controlled the variety of species at a local and regional level. However, on a global level there was another factor driving the evolution of species forward: plate tectonics. At the beginning of the Cambrian Period, the supercontinent Pannotia broke apart. From then on, deep oceans separated parts of the land and the different sea creatures evolved separately.

'We saw a significant increase in provincialism. The species composition found in the continents' different old shelf seas became more and more different. This could be the main reason that the total number of species increased so considerably,' says Lin Na.

*Lin Na, Wolfgang Kießling: 'Diversity partitioning during the Cambrian radiation', Proceedings of the National Academy of Sciences (USA). doi: 10.1073/pnas.1424985112

Further information:
Lin Na
lin.na@fau.de

Prof. Dr. Wolfgang Kießling
Phone: +49 9131 8526959
Wolfgang.kiessling@fau.de

Media Contact

Dr. Susanne Langer idw - Informationsdienst Wissenschaft

More Information:

http://www.fau.de/

All latest news from the category: Earth Sciences

Earth Sciences (also referred to as Geosciences), which deals with basic issues surrounding our planet, plays a vital role in the area of energy and raw materials supply.

Earth Sciences comprises subjects such as geology, geography, geological informatics, paleontology, mineralogy, petrography, crystallography, geophysics, geodesy, glaciology, cartography, photogrammetry, meteorology and seismology, early-warning systems, earthquake research and polar research.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors