Humans Homo sapiens are a species of highly intelligent primates. They are the only extant members of the subtribe Hominina and—together with chimpanzees , gorillas , and orangutans —are part of the family Hominidae the great apes , or hominids. Humans are terrestrial animals , characterized by their erect posture and bipedal locomotion ; high manual dexterity and heavy tool use compared to other animals ; open-ended and complex language use compared to other animal communications ; larger, more complex brains than other primates; and highly advanced and organized societies. Several early hominins used fire and occupied much of Eurasia. Early modern humans are thought to have diverged in Africa from an earlier hominin around , years ago, with the earliest fossil evidence of Homo sapiens also appearing around , years ago in Africa.
Waikato Radiocarbon Dating Laboratory
Liquid Scintillation Counting
Swamp kauri has revealed more about a mysterious event 42, years ago. Secrets hidden within ancient swamp kauri have revealed a temporary breakdown of Earth's magnetic field 42, years ago, prompting global environmental change and mass extinctions. This dramatic turning point in Earth's history was triggered by a reversal of Earth's magnetic poles and changing solar winds. The episode has now been dubbed the "Adams Transitional Geomagnetic Event", or "Adams Event" for short - a tribute to science fiction writer Douglas Adams, who wrote in The Hitchhikers Guide to the Galaxy that "42" was the answer to life, the universe, and everything. The findings were made possible with ancient New Zealand kauri trees, which have been preserved in sediments for more than 40, years. Using the ancient Northland trees, Turney, of the University of New South Wales, and his Kiwi and Australian colleagues were able measure, and date, a spike in atmospheric radiocarbon levels caused by the collapse of Earth's magnetic field. Cross-sections from several swamp kauri in Niwa's archive were analysed by Dr Andrew Lorrey to determine their age.
This timeline of the evolutionary history of life represents the current scientific theory outlining the major events during the development of life on planet Earth. In biology , evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organization , from kingdoms to species , and individual organisms and molecules , such as DNA and proteins. The similarities between all present day organisms indicate the presence of a common ancestor from which all known species, living and extinct , have diverged through the process of evolution.
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