| Evolutionary History Of Life |
Article Index for Evolutionary |
Shopping Evolutionary |
Website Links For Evolutionary |
Information AboutEvolutionary History Of Life |
| CATEGORIES ABOUT EVOLUTIONARY HISTORY OF LIFE | |
| evolution | |
| history by topic | |
|
The evolutionary history of life and the Origin Of Life are fields of ongoing geological and biological research. Although it is not necessary to understand the origin of life on earth to accept evolution by natural selection, Accessed 13 May 2007 the origin of life and its evolutionary history can help shed light on evolutionary processes. The current Scientific Consensus is that the complex Biochemistry that makes up life came from simpler chemical reactions, but it is unclear how this occurred.1 Not much is certain about the earliest developments in life, the structure of the first living things, or the identity and nature of any Last Universal Common Ancestor or ancestral gene pool.234 Consequently, there is no scientific consensus on how life began, but proposals include self-replicating molecules such as RNA ,5 and the assembly of simple cells.6 The first simple, sea dwelling organic structures appeared about 3,400 million years ago. It is considered that they may have formed when certain chemical (organic) molecules joined together. Prokaryote s, single-celled micro-organisms like blue green algae, were able to photosynthesize and produce Oxygen . Around thousand million years later, sufficient oxygen had built up in the Atmosphere and hence it allow multicellular organisms to proliferate in the Precambrian seas.Soft-bodied jellyfish , corals, and sea worms flourished about 700 Million years ago. Trilobites, the first animals with hard body frames, developed during the Cambrian period. About 363 million years ago amphibians came into existence. It was only after the appearance of reptiles that were independent of water. EARLY SIGNS OF LIFE . DNA is far more complex than the original replicator and its replication systems are highly elaborate.]] See Also: Origin of life | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||