Question

Explain when did life begin? (Scientific theory)

Answer 1

Answer:

First scientific theory on origin of life came from Russian biochemist Alexander Oparin which stated that first life on earth appeared through chemical evolution .

Explanation:

Chemical evolution theory supports evolution of life through abiogenesis. Oparin's idea received immediate support from Haldane who also thought that life evolved through abiogenesis in primitive ocean which was described as hot prinordial soup by Haldane himself.

Scientific proof in favour of chemical evolution theory came much later through innovative simulation experiments , conceptualised and pioneered by Harold Urey and Stanley Miller in 1950s. Such experiments were conducted in flasks containing gaseous mixtures, closely mimicking primitive atmosphere of earth.

Such simulation experiments showed that biologically important organic molecules like amino acids could have been generated in a reducing primitive atmosphere. Those molecules also generated polymers like proteins. Aggregated protein molecules formed coacervates in the primitive sea; eventually lipid bilayer appeared around coacervates.

Chemical evolution gave rise to nucleotides and first nucleic acid was definitely RNA , which in the beginning of life on earth acted both as a genetic material and as an enzyme inside the first generation of cells.

Answer

Answer 2

The earliest life forms that 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

What science say about origin of life :

The origin of life on Earth is a set of paradoxes. In order for life to have gotten started, there must have been a genetic molecule—something like DNA or RNA—capable of passing along blueprints for making proteins, the workhorse molecules of life. ... Now, researchers say they may have solved these paradoxes.


If talking about Big Bang i don’t know I read it wrong but I’m not deleting this because I’m not feeling up to it right now : )


Big Bang Theory.｡oO┌(;￣◇￣)┘

In basic terms:
An atom exploded and made everything.... but keep in mind...( energy cannot be created not destroyed)

The scientific theory: