An “extreme cooling event” probably wiped out a population of the primitive human species Homo erectus around 1.1 million years ago, according to a recent study.
The researchers speculate that the hitherto unrecognized temperature decline corresponds with what is known about human occupancy of the continent. Homo erectus arrived in Europe from Asia between 1.8 million and 1.4 million years ago, according to fossils and stone tools, but they appear to have disappeared from the continent around 1.1 million years ago.
The next archaic human remains found in Europe date to around 900,000 years ago, presumably following the arrival of a later and more robust species, Homo antecessor, from Africa or Asia.
“There’s an apparent gap of 200,000 years,” said Chronis Tzedakis, a senior author of the paper and a paleoclimatologist at University College London, to Live Science. According to the new research, which was released on August 10 in the journal Science, this gap occurs at the same time as the newly discovered cooling phase, which shows that the cold drove or wiped off any ancient humans.
Ocean evidence
Marine sediment cores taken from the ocean floor off the coast of Portugal contained proof of the cooling, according to the researchers. Their examination of the elements isotopes in the remains of marine plankton from the ocean’s surface and bottom, as well as their examination of pollen grains from plants on land, revealed an abrupt cooling that occurred around 1.15 million years ago.
According to Tzedakis, the water temperature near Lisbon, which is currently on average approximately 70 degrees Fahrenheit (21 degrees Celsius), dropped to about 43 degrees Fahrenheit (or 6 degrees Celsius), and the continent of Europe experienced a comparable cold episode, which may have led its northern ice sheets to move southward.
In addition, scientists found evidence of a steady inflow of cold water beginning at 1.13 million years ago, which they attribute to meltwater from the melting of Europe’s ice sheets as the continent warmed.
According to accepted timeframes, the last ice age peaked at 900,000 years ago, but Tzedakis said our planet has gone through countless cold and warm phases before that. Although there have been theories regarding an even earlier cold era that occurred around 1.1 million years ago, he added there has never been concrete proof of it.
The primary cause of the cooling appears to have been astronomical: According to Tzedakis, Jupiter’s gravitational pull caused Earth’s orbit to be roughly circular at the time, which is a condition linked to previous cooling stages of our planet’s climate.
Although it is unknown whether this was the cause of the cooling or one of its effects, the amount of the greenhouse gas carbon dioxide in the Earth’s atmosphere decreased significantly during this time.
Intense cold
Marine sediment cores taken from the ocean floor off the coast of Portugal contained proof of the cooling, according to the researchers. Their examination of the elements isotopes in the remains of marine plankton from the ocean’s surface and bottom, as well as their examination of pollen grains from plants on land, revealed an abrupt cooling that occurred around 1.15 million years ago.
According to Tzedakis, the water temperature near Lisbon, which is currently on average approximately 70 degrees Fahrenheit (21 degrees Celsius), dropped to about 43 degrees Fahrenheit (or 6 degrees Celsius), and the continent of Europe experienced a comparable cold episode, which may have led its northern ice sheets to move southward.
In addition, scientists found evidence of a steady inflow of cold water beginning at 1.13 million years ago, which they attribute to meltwater from the melting of Europe’s ice sheets as the continent warmed.
According to accepted timeframes, the last ice age peaked at 900,000 years ago, but Tzedakis said our planet has gone through countless cold and warm phases before that. Although there have been theories regarding an even earlier cold era that occurred around 1.1 million years ago, he added there has never been concrete proof of it.
The primary cause of the cooling appears to have been astronomical: According to Tzedakis, Jupiter’s gravitational pull caused Earth’s orbit to be roughly circular at the time, which is a condition linked to previous cooling stages of our planet’s climate.
Although it is unknown whether this was the cause of the cooling or one of its effects, the amount of the greenhouse gas carbon dioxide in the Earth’s atmosphere decreased significantly during this time.
