Search results
Results from the WOW.Com Content Network
At least two-thirds of Mars' surface is more than 3.5 billion years old, and it could have been habitable 4.48 billion years ago, 500 million years before the earliest known Earth lifeforms; [4] Mars may thus hold the best record of the prebiotic conditions leading to life, even if life does not or has never existed there. [5] [6]
In human genetics, the Mitochondrial Eve (more technically known as the Mitochondrial-Most Recent Common Ancestor, shortened to mt-Eve or mt-MRCA) is the matrilineal most recent common ancestor (MRCA) of all living humans. In other words, she is defined as the most recent woman from whom all living humans descend in an unbroken line purely ...
The research also located a possible origin of modern human migration in southwestern Africa, near the coastal border of Namibia and Angola. [252] The fossil evidence was insufficient for archaeologist Richard Leakey to resolve the debate about exactly where in Africa modern humans first appeared. [253]
This week, explore the technology that could allow humans to live on Mars, uncover the truth of a Neanderthal flower burial, see a leggy birdlike dinosaur, and more.
[10] [11] Carl Zimmer has speculated that the chemical conditions, including boron, molybdenum and oxygen needed to create RNA, may have been better on early Mars than on early Earth. [12] [13] [14] If so, life-suitable molecules originating on Mars would have later migrated to Earth via meteor ejections.
The first known mass extinction was the Great Oxidation Event 2.4 billion years ago, which killed most of the planet's obligate anaerobes. Researchers have identified five other major extinction events in Earth's history, with estimated losses below: [ 11 ]
Human history is the record of humankind from prehistory to the present. Modern humans evolved in Africa around 300,000 years ago and initially lived as hunter-gatherers.They migrated out of Africa during the Last Ice Age and had spread across Earth's continential land except Antarctica by the end of the Ice Age 12,000 years ago.
H. erectus is the first known species to develop control of fire, by about 1.5 Ma. H. erectus later migrates throughout Eurasia, reaching Southeast Asia by 0.7 Ma. It is described in a number of subspecies. [38] Early humans were social and initially scavenged, before becoming active hunters.