I think you may be misunderstanding what the original point was in regards to this. I was saying that tests done to see if evolution through mutational changes to proteins can find the precise structures needed for life in among the billions of possibilities.
1. you're assuming that they were as precise when life first formed as they are now, which is not the case. All living cells on Earth have acquired billions of years of added complexity and specificity that is not inherently necessary for life, just for modern life. Also, there is a decent amount of variation in the protein needs of various modern organisms, and plenty of organisms don't produce them themselves, but rather consume them from the environment or other organisms.
2. I request a source for your claim, preferably a scientific journal.
3. Natural selection applies to proteins as well; life developed in steps, not all at once, thus, say, a cell wall could form first, and then a replicating molecule could get trapped in it, and find the protective covering and closed environment improved it's ability to reproduce. then, any replicating molecule which could also replicate the cell wall would have an advantage over those that couldn't, and so on and so forth. Those many possibilities are not equally likely, and it would be jumping the gun to assume the more basic proteins necessary for life are somehow rare or unlikely to form on their own, when in reality, most abiogenesis experiments generate some of them.
I said tests showed it unlikely and even if it was possible to make small changes it takes a very long time. I used the example of how scientists talk about the millions of years it takes for something to evolve or the 3 plus billion years it took to go from single celled life to multi celled life. Hoghead 1 said that they know how evolution works from the fossil records. I said the fossil records show that it took a long time anyway.
I dont even know why geology was brought into it anyway as I was talking about how long it takes evolution to evolve complex life to show that its not an easy thing to do and requires time. Going from pint A to point B isn't just a case of a straight line and easily finding the right ingredients. The evidence shows that there is a lot more to making life and mutations through natural selection doesn't seem to have what it takes to do it because of the hit and miss process it involves. What we see is that many different and distantly related creatures find similar designs right down to the molecular level over and over again as though the code for life was pre determined or the genetic info is somehow available to many creatures without having to somehow find it through adaptations. That there are set paths that are followed rather then a tit for tat process of trial and error.
Mutations are very common, and single celled organisms have huge populations. Every person on the planet has 40-60 approximate mutations in their DNA that they don't share with either of their parents. So, let's do the math, giving highly critical numbers towards benign mutations at 5% (even though they have been measured to occur at a much higher rate than that). Currently, about 353,000 people are born per day, making the number of mutations in the human population per day between 14,120,000 and 21,180,000. Let me be extra skeptical, and cut the lower number in half and use that in the calculation for the number of mutations in the human population per year, which, when I do that, comes out to 2,576,900,000 mutations per year. Now, to apply the 5% for how many of those will be benign, and that comes out to 128,845,000 benign mutations in the human population per year currently. I know that this isn't exactly representative for the size of the human population historically, but I'm using an example of how prevalent benign mutations can be. Consider also that a few petri dishes of bacteria can have a higher population than the current ones for our own species, and you begin to see exactly how frequent benevolent mutations occur.
Inevitable comment: "But Sarah, aren't malevolent mutations way more common than benevolent ones?" Actually, the majority of mutations are neutral, meaning they don't provide any benefit or detriment. In reality, negative mutations are a bit more frequent than beneficial ones, but through a combination of being selected against through death and reproductive failure, the worst of them will never become prominent in any population (think of how common miscarriages are. One of the common causes is detrimental mutations in genes necessary for proper development and living). Hence, even if the frequency of bad mutations was something crazy, like 80%, and benign mutations were only a fraction of a percent, natural selection would still act upon them; evolution would just be slower.
Additionally, it is not uncommon for single genes to have multiple impacts on the body, so even changing one gene can have a huge immediate effect on physiology.
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