If you mean the mechanics of DNA itself, there have been some variations. Prior to DNA there was RNA. The evolution of DNA required catalytic precursors and mechanisms to translate between RNA and DNA and represents a major advancement in the history of life.
As far as why more extensive and variable changes apparently haven't occurred I can only speculate. There are an infinite number of ways the information of life could potentially be stored. It's an interesting topic. Different chemical structures probably do exist somewhere in the universe. Besides storing information, DNA is also catalytically active and is not as simple as a purely mechanical (punch card) style of memory. DNA is well suited for use in an aqueous environment (inside a cell) and life on Earth is strongly dependent on the molecular properties of water. If, for example, a polymer chain (say made of polyethylene plastic) was studded with "impurities" to encode information for life, it would first have to be transcribed into a form that could participate in the chemical reaction. However polyethylene is so inert in water, that it might be too difficult or impossible for such a mechanism to develop. Water would not be the solvent to use for plastic "DNAs".
Life as it is now, assuming that it could have been different, seems to be stuck with this at it's core.
by davidwpa 7 years ago
Does the Earth have the same mass today as it did billions of years ago?If mass is constant but changes form, does the Earth with 6 billion people on it now have the...same mass as it did a billion years ago when there was very few or no humans here? In other words does the population...
by Money Man 2 years ago
Why did God wait billions of years before making an appearance in the form of Jesus?Religion seems to be a hot topic right now. I would love to hear from religious people about this topic. Why did God not make his appearance 1 or two billion years ago?
by Jasmin 4 years ago
My hubscore hasn't changed in over a week is this down to the technical issues hubpages are having?I have seen that there are a few issues with Hubpages, My score hasn't changed in a week now is this due to the technical issues they are having?
by The Reluctant Revivalist 2 years ago
Is the earth billions of years old or thousands of years old?
by aka-dj 7 years ago
I found the following article most interesting.It's not for the non-technical minds, but not too difficult to grasp what is being said. http://biologicinstitute.org/2011/04/16 … t-collide/See what you think.
by aka-dj 5 years ago
I mentioned the phrase "flaws in evolution" in the context of challenging the constant assertion by may that evolution is a proven well understood and accepted fact, as opposed to a flawed theory.Proponents of evolution in Hubpages don't like facing these issues, as it messes with their...
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