Many scientists believe that RNA, or something similar to RNA, was the first molecule on Earth to self-replicate and begin the process of evolution that led to more advanced forms of life, including human beings.
However, recently some scientists have narrowed in on the hypothesis that life originated near a deep sea hydrothermal vent. The chemicals found in these vents and the energy they provide could have fueled many of the chemical reactions necessary for the evolution of life.
The earliest life forms we know of were microscopic organisms (microbes) that left signals of their presence in rocks about 3.7 billion years old. The signals consisted of a type of carbon molecule that is produced by living things.
Homo sapiens, the first modern humans, evolved from their early hominid predecessors between 200,000 and 300,000 years ago. They developed a capacity for language about 50,000 years ago. The first modern humans began moving outside of Africa starting about 70,000-100,000 years ago.
Adam is the name given in Genesis 1-5 to the first human. Beyond its use as the name of the first man, adam is also used in the Bible as a pronoun, individually as "a human" and in a collective sense as "mankind".
Evidence shows that life probably began in the ocean at least 3.5 billion years ago. Photosynthesis began more than 2.5 billion years ago—the Great Oxidation Event. But it took hundreds of millions of years for enough oxygen to build up in the atmosphere and ocean to support complex life.
Hominins first appear by around 6 million years ago, in the Miocene epoch, which ended about 5.3 million years ago. Our evolutionary path takes us through the Pliocene, the Pleistocene, and finally into the Holocene, starting about 12,000 years ago. The Anthropocene would follow the Holocene.
But Earth did not always exist within this expansive universe, and it was not always a hospitable haven for life. Billions of years ago, Earth, along with the rest of our solar system, was entirely unrecognizable, existing only as an enormous cloud of dust and gas.
All life forms share at least one essential purpose: survival. This is even more important than another key purpose for life, reproduction. Plenty of organisms, after all, are alive but do not reproduce.
Currently, the most favored explanation for where the Earth got its water is that it acquired it from water-rich objects (planetesimals) that made up a few percent of its building blocks. These water-rich planetesimals would have been either comets or asteroids.
All of the planets, except for Earth, were named after Greek and Roman gods and godesses. The name Earth is an English/German name which simply means the ground. It comes from the Old English words 'eor(th)e' and 'ertha'. In German it is 'erde'.
Co-lead researcher Shimona Kealy said these people probably travelled through Indonesia's northern islands, into New Guinea and then Australia, which were part of a single continent between 50,000 and 70,000 years ago, when sea levels were 25-50 metres below the current level.
From about 1.2 million years ago to less than 100,000 years ago, archaic humans, including archaic Homo sapiens, were dark-skinned.
A new genetic study suggests all modern humans trace our ancestry to a single spot in southern Africa 200,000 years ago.
IN 4.5 billion years of Earthly history, life as we know it arose just once. Every living thing on our planet shares the same chemistry, and can be traced back to “LUCA”, the last universal common ancestor.
First cells likely arose in steamy mud pots, study suggests. Earth's first cellular life probably arose in vats of warm, slimy mud fed by volcanically heated steam—and not in primordial oceans, scientists say. (Also see "All Species Evolved From Single Cell, Study Finds.")
The discovery pushed back the time for the emergence of microbial life on land by 580 million years and also bolstered a paradigm-shifting hypothesis laid out by UC Santa Cruz astrobiologists David Deamer and Bruce Damer: that life began, not in the sea, but on land.
Basic math tells us that all humans share ancestors, but it's amazing how recently those shared ancestors lived. Thanks to genetic data in the 21st century, scientists are discovering that we really are all descended from one mother.
Genetic studies have demonstrated that humans are still evolving. To investigate which genes are undergoing natural selection, researchers looked into the data produced by the International HapMap Project and the 1000 Genomes Project.
Humans lost their body hair, they say, to free themselves of external parasites that infest fur -- blood-sucking lice, fleas and ticks and the diseases they spread. Once hairlessness had evolved through natural selection, Dr. Pagel and Dr.
It is true that there has been, historically, a small number of claims that there were people in Australia before Australian Aborigines, but these claims have all been refuted and are no longer widely debated.
Aboriginal and Torres Strait Islander peoples are the first peoples of Australia, meaning they were here for thousands of years prior to colonisation.
Prior to that time, were 1,000-pound kangaroos in Australia, 2-ton wombats, 25-foot-long lizards, 400-pound flightless birds, 300-pound marsupial lions and Volkswagen-sized tortoises. After that time, those huge creatures had disappeared.
Earth is estimated to be 4.54 billion years old, plus or minus about 50 million years. Scientists have scoured the Earth searching for the oldest rocks to radiometrically date.