How did life on earth form?

Answer 1

In the natural sciences, abiogenesis, or origin of life, is the study of how life on Earth could have arisen from inanimate matter. It should not be confused with evolution, which is the study of how living things change over time. Amino acids, often called "the building blocks of life", occur naturally, due to chemical reactions unrelated to life. In all living things, these amino acids are organized into proteins, and the construction of these proteins is mediated by nucleic acids. Thus the question of how life on Earth originated is a question of how the first nucleic acids arose.

Some facts about the origin of life are well understood, others are still the subject of current research. The first living things on Earth are thought to be single cell prokaryotes. The oldest ancient fossil microbe-like objects are dated to be 3.5 Ga (billion years old), just a few hundred million years younger than Earth itself.[1][2] By 2.4 Ga, the ratio of stable isotopes of carbon, iron and sulfur shows the action of living things on inorganic minerals and sediments[3][4] and molecular biomarkers indicate photosynthesis, demonstrating that life on Earth was widespread by this time.[5][6]

On the other hand, the exact sequence of chemical events that led to the first nucleic acids is not known. Several hypotheses about early life have been proposed, most notably the iron-sulfur world theory (metabolism without genetics) and the RNA world hypothesis (RNA life-forms).

Answer 2

Scientists believe that life began from bacteria, or some type of matter. Over thousands of years that matter, or bacteria began to evolve. It began to adapt to it's environment. Chemical reactions inside the small tiny organisms began to make it create cells and amino acids, which are the building blocks of life. Since cells duplicate the tiny organisms began to grow over time, eventually getting bigger and bigger, growing limbs, a mouth and whatever it needed to survive to the changing environment, thus creating the dinosaurs.