How the life began on Earth is a question that might not ever be answered during our lifetime for certain. However, there is a new theory being looked at. Instead of assuming RNA was evolved into DNA and proteins, the new theory assumes that RNA and DNA evolved simultaneously. Researchers at The Scripps Research Institute discovered that there is a significant loss of stability when RNA and DNA share the same backbone which they would have if it was a RNA world. The instability would cause difficulties in the ability to hold information and replicate correctly. There showed to be a loss of function when RNA and DNA were mixed. The researchers have come to the conclusion that RNA in the beginning would have been altered like they are today if RNA nucleobases accidentally join a DNA strand; enzymes will come and fix this mistake. The researchers have assumed that the sophisticated enzymes were probably not around at this time. If DNA and RNA arose at the same time, DNA would have had its own homogeneous system early on. RNA would have still produced DNA but DNA would have had its own raw material first.
To read more: http://www.scripps.edu/newsandviews/e_20161003/krishnamurthy.html
I don't understand this at all. No one thinks that RNA evolved into DNA and proteins so much that RNA was initially both the molecule of heredity and metabolism; and later, DNA took over the first function and proteins the second.
ReplyDeleteIf DNA and RNA shared the same backbone, wouldn't they be the same thing? Its the sugar backbone that distinguishes them, isn't it?
Really confused here.
There should have been a sentence before the statement about DNA and RNA sharing a backbone. If the RNA world theory was correct, researchers believe there would have been cases where RNA nucleotides were mixed with DNA backbones creating heterogeneous strands. This is where the stability is lost, not from RNA and DNA sharing the same backbone.
DeleteWhy would this information be significant? Here's a new theory to "the chicken came before the egg or vise versa" -- they came at the same time! Ok, but in all seriousness, how can this information help us understand the fundamentals of biology?
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