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We often hear skeptics of the theory of evolution say something like, “Scientists can’t even tell us for sure where the first living cell came from so they can’t possibly know how all other life forms on Earth evolved from it.” The first assertion is true, the second is not. Evolutionary biologists are still debating several different scenarios as to how the first living cell originated, but the most popular one is that it formed from chemical clusters near a deep volcanic vent in the sea.
The first cell became a “living” one when it acquired the means to obtain nutrients, convert them to energy, dispose of waste by-products, reproduce and then to die. Absorbing nutrients from its surroundings and disposing of its waste required the chemical cluster be contained within a suitable semi-permeable membrane. Reproducing required the cluster to have a DNA molecule. Where did all the complex chemicals, DNA and cell membrane come from?
For a billion years after its formation, Earth was a virtual chemical factory, accelerating its productivity after the moon arrived to start producing tidal movements of Earth’s oceans. Earth had accumulated abundant amounts of simple organic and inorganic chemicals that reacted to form some complex ones. Basic chemicals such as ammonia and acetic acid produced amino acids which eventually polymerized into proteins. Carbohydrates such as starches, sugars and fats (phospholipids) were synthesized. Phospholipids are necessary components of cell membranes. More complex organic compounds combined with inorganic ones to make nitrogen bases (components of DNA) and chelates that are necessary ingredients of hemoglobin (blood) and chlorophyll (plants). Of course, during this enormous time period many trillions of other chemical interactions were taking place to form many compounds that eventually became useful tools for the development of life. Vast quantities of these chemicals became concentrated into clusters and became organized around hot volcanic vents in the oceans. Tidal movements and radiation impacts (from our sun and other bodies from around our galaxy) provided a continuous stirring of the oceans, which brought fresh chemicals to react with growing molecules. These larger molecules provided the tools for the formation of proteins, enzymes, and a very unique molecule called DNA that is the only molecule that is able to make exact copies of itself. Once this molecule and the enzymes that could replicate it were formed, the only ingredient that would still be needed to produce all the life forms that ever existed on Earth was TIME!
Read Settled Science to see how this first living cell, that required a billion years to form, in a matter of days began the evolutionary process of mutation, natural selection and genetic drift to build a vast population of diverse strains where the larger, more aggressive, and better equipped ones began eating the less efficient ones for food; and how over time initiated the very important processes of photosynthesis, respiration, death and biodegradation, and over a 3.5 billion year period modified themselves into all other living things.
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