Faced with the failure of the Stanley-Urey model to explain the origin of life, evolutionary scientists have been exploring the RNA World theory. With only the four nucleic acids required to form RNA (pictured left) rather than the twenty amino acids to form a protein, the chance probability tipped the advantage to the RNA-first theory, but that is not all.
“This is the RNA World. To see how plausible it is, we need to look at why proteins are good at being enzymes but bad at being replicators; at why DNA is good at replicating but bad at being an enzyme; and finally why RNA might just be good enough at both roles to break out of the Catch-22.”
The RNA World theory solved the chicken-or-the-egg Catch-22 conundrum. At least that was the hope. Notice Dawkins’s use of the word “plausible.” Building proteins requires the information from DNA, but the information in DNA requires enzymes that are proteins—the Catch-22.
In the mid twentieth century, using a simple laboratory experiment, Stanley Miller (pictured left) and Harold Urey (pictured right) was the first to demonstrate how life may have started from simple molecules and energy. In the excitement, addressing the scope of the Miller-Urey probability issue was postponed.
The Stanley-Miller origin of life model was once the most popular theory, starting with the publication of The Planets: Their Origin and Development in 1952. Written by Harold Urey, the book speculates that life originated in early Earth’s atmosphere composed of ammonia, methane, and hydrogen—a reducing atmosphere without oxygen.
“This little creature is going to show us our connection with the rest of all the mammals; with cows and sheep, and elephants and anteaters,” said Sir David Attenborough, who narrated the BBC documentary in May 2009. “The more you look at Ida, the more you can see, as it were, the primate in embryo” – signaling the beginning of the Ida fossil fiasco.
The media hype later became known as the Ida fossil fiasco.
“It tells a part of our evolution that’s been hidden so far. It’s been hidden because the only [other] specimens are so incomplete and so broken there’s nothing almost to study”, said Dr. Jørn Hurum, the paleontologist from Oslo University’s Natural History Museum who assembled the scientific team. The fossil findings were released to the world at a press conference in New York, simultaneously with the online publication of the paper in the Public Library of Science(PLoS ONE) on May 19, 2009.
Darwin, Then and Now chronicles who Darwin was, how he developed his theory, what he said, and what scientists have discovered since the publication of The Origin of Species in 1859.
The book traces the rise and fall of evolution as a scientifically valid theory. With over 1,000 references from Darwin and scientists, Darwin Then and Now retraces how this once popular theory is increasingly recognized as only a philosophy since the theory has yet to be scientifically validated.