How to emerge as evolution’s top gun

CARDIFF U. (UK) — Marine plankton are offering new insight into the winners and losers of a 65 million year long evolutionary race to the finish.

“Importantly this fossil record has recorded what happens to foraminifera in terms of diversity and abundance across an extensive period of time when environmental conditions in the oceans were very different to our modern oceans,” says Tracy Aze,  of Cardiff University.

The research, published in the journal Science, finds that species are more likely to become extinct if they are “older” disputing a well established theory that the probability of extinction in groups of organisms is constant and not dependent on age.

The findings also say the emergence of new species is more likely to occur early on in the lifetime of pre-existing ancestor species.

Addressing evolutionary questions dating from both Charles Darwin and his contemporary Alfred Russel Wallace, the research looks at how competition between species alive at the same time and environmental change influenced extinction and emergence of new species.

Darwin thought that environment played a more important role in natural selection, Wallace thought that interaction between species was more dominant.

By incorporating detailed information about species ecologies the study says both theories were important in shaping a group’s evolution.

“If we are to attempt to conserve global biodiversity and maintain global ocean ecosystems we need to understand how organisms respond to environmental change,” Aze says.

“Our research has shown that extinction is more strongly influenced by changes in the environment, while the emergence of new species – known as speciation – is more strongly influenced by the interactions between species.”

Researchers from Imperial College London contributed to the study that was, funded by the Natural Environment Research Council (NERC).

A live Globigerinella siphonifera. (Credit: Thomas Ezard)

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