Origin of Life – Evolution of Life Forms

Several competing explanations have been offered for how life on Earth began. Special creation holds that a supernatural power, respectfully called God, brought life into existence — Hinduism credits Lord Brahma, while Christianity, Islam and most other religions hold that God created the universe, the plants and the animals. Spontaneous generation (abiogenesis) proposed instead that living organisms arose directly from non-living matter through a stepwise chemical and molecular process spread over millions of years; the term abiogenesis itself was coined by Thomas Huxley. The Big Bang theory, which explains the origin of the universe as a single vast explosion, is also linked to an account of early Earth: the primitive planet had no real atmosphere, only ammonia, methane, hydrogen and water vapour at an extremely high temperature; UV rays from the sun split water into hydrogen and oxygen, the planet gradually cooled, water vapour condensed into rain that filled depressions to form water bodies, and ammonia and methane combined with oxygen to yield carbon dioxide and other gases. Biogenesis — the opposing view that life can only arise from pre-existing life — was named by Henry Bastian. …