Modern lifeforms appeared when the sea temperatures reached 25˚C (77˚F), which is 5 degrees higher than today’s averages. The temperatures rose up at the time rapidly, according to scientists from the University of Leicester, The Independent reported.
The humanity evolved thanks to global warming, according to scientists
About 540 million years ago there was a so-called “Cambrian explosion”. It was the time when a variety of different animals and plants “suddenly” appeared on the face of the planet Earth. The novel varieties included chordates, the ancestors of today’s vertebrates, the brunch of life forms that includes humans.
Scientists have long suspected this was a particularly warm period in the history of the Earth, but only now they have managed to prove it by researching facts of life that long time ago.
How to find out the temperature of seas half a billion years ago?
Obviously, scientists cannot directly measure the temperature of the sea 500 million years ago. Therefore, for the experiment, academics used isotopes of oxygen, which are a popular paleothermometer. These isotopes were extracted from tiny fossil shells from limestone blocks. It is believed that these shells can be up to 515 million years old.
“Careful examination of these tiny fossils revealed that some of them have exceptionally well-preserved shell chemistry which has not changed since they grew on the Cambrian sea floor,” explained Thomas Hearing, a PhD student at the University of Leicester who has led the study.
Dr Tom Harvey, a geologist at the University of Leicester who co-authored the study, added: “Many marine animals incorporate chemical traces of seawater into their shells as they grow.
Having studied the levels of oxygen isotopes, scientists were able to get a clear idea of what the sea temperature were during the Cambrian period. Their study showed that in the high-latitude oceans the waters warmed up to 25 degrees, which is approximately 5 degrees higher than now. In modern terms, the Cambrian explosion occurred against a background of global warming.
The scientists believe their research should help understand the conditions that gave rise to many of the animal forms which are still found on Earth today.
So, what do you think of the global warming of today? Maybe, some other novel life forms are already starting to propagate, unnoticed by us?