Some say that life on Earth originated from an asteroid. For example, scientists studying the asteroid Ryugu believe that life on Earth may have been brought by an asteroid.
Others say that it’s unlikely that life on Earth originated from extraterrestrial origins. Cells would have to survive extreme conditions of vacuum, heat, and cold to get from where they did evolve in the first place.
However, recent experiments have suggested that earthly organisms can survive in space, at least for a little while.
The panspermia theory states that life exists throughout the universe and is distributed by space dust, meteoroids, asteroids, comets, and planetoids. The theory suggests that life originated in outer space and was transported to Earth by meteorites, asteroids, or comets.
The theory is supported by the fact that astronomers have found organic molecules on comets and asteroids. The theory states that microbial spores from space were brought to Earth by asteroids or meteors, which jump-started life on Earth.
The theory was proposed by Richter in 1865 and supported by Arrhenius (1908) and other contemporary scientists
Scientists have found amino acids, carbon, hydrogen, nitrogen, and waterin asteroids. These molecules are thought to be the building blocks of life.
The asteroid Ryugu contains:
- Uracil, one of the four building blocks of RNA
- Niacin and other compounds that are important for living organisms
- More than ten types of amino acids, including glycine and L-alanine
NASA found traces of carbon and water in a 4.5-billion-year-old asteroid
Some researchers believe that the Murchison, Murray, and Tagish Lake meteorites may have started life on Earth. The Murchison meteorite landed in Australia in 1969, and the Murray and Tagish Lake meteorites landed in the US in 1950 and Canada in 2000, respectively.
Japanese researchers led by Hokkaido University obtained samples from these meteorites. The samples contained organic compounds essential for living organisms.
NASA says that comets may have brought the building blocks of life to Earth 3.8 billion years ago. However, subsequent cometary collisions may have wiped out many of the developing life forms, allowing only the most adaptable species to evolve further
The earliest life on Earth was likely coacervates, which were protein-based spheres with lipid membranes. Coacervates accumulated material from seawater and grew in size. They’re often called protobionts.
The first prokaryotic cellular life evolved 3.5 billion years ago through a process called abiogenesis. Scientists believe that RNA, or something similar to RNA, was the first molecule on Earth to self-replicate.
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. Some of the oldest evidence of life on Earth is 3.49-billion-year-old fossilized remains of microbial mat structures, which look like wrinkle marks in rocks.
Some scientists suggest that deep-sea hydrothermal vents were the birthplaces of Earth’s first life forms. These chimney-like vents form where seawater comes into contact with magma on the ocean floor, resulting in streams of superheated plumes.
Humans evolved in Africa. The fossils of early humans who lived between 6 and 2 million years ago come entirely from Africa. One of the earliest known humans is Homo habilis, who lived about 2.4 million to 1.4 million years ago in Eastern and Southern Africa.
Some say Mars is the likely location of Earth’s first infusion of life from other planets. Mars has all the requirements for life, including liquid water, organic compounds, essential elements and minerals, and access to energy sources. However, no proof of past or present life has been found on Mars.
According to the Bible, the first person on Earth was Adam, who was created by God on the sixth day of creation. The earliest life forms on Earth were microscopic organisms (microbes) that left signals of their presence in rocks about 3.7 billion years old. The first animal on Earth was the ocean-drifting comb jelly, which evolved in the sea over half a billion years ago
According to the Bible, Adam and Evewere the first man and woman. They lived in the Garden of Eden before being expelled for disobeying God. The belief that humanity is a single family, descended from a single pair of original ancestors, is central to the creation myth of the Abrahamic religions.
In other religions, the first man and woman are:
- Hinduism: Manu and Shatarupa
- Navajo: Altsé hastiin and Altsé asdzáá
- Anuak tribe of Sudan: Otino and Akongo
Universe discoveries 