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In this answer, the author argued that plants are green instead of red or any other color because of some limitations of the evolutionary process. what are other examples in which the physical and functional characteristics of an organism were a direct result of limitations of evolution?

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    $\begingroup$ What does "absolute highest peak on the fitness scale" mean? There really is no such thing, unless perhaps you think of a biological grey goo sort of scenario. $\endgroup$ – Bryan Krause Jul 9 '18 at 16:26
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The "limitations" of evolution is somewhat subjective, I suppose, but a couple of the important ones include random mutations, lack of foresight, and environment. Evolution is a complex process by which mutations occur which either benefit an organism, making it more fit, harming the organism, leading (usually) to death, or to no noticeable change. Over time, these mutations bring about significant phenotypic changes. There's no goal, no purpose to it. In your example of plants, chlorophyll could certainly have evolved a structure that absorbed light in different wavelengths.

Another example is the difference between the vertebrate eye vs the octopus eye. For mammalian eyes, the optic nerve covers part of the retina. This is commonly known as the "Blind spot". For Cephalopods, on the other hand, the optic nerve is located behind the retina, so they have no bind spot.

Both of these examples are the result of random mutations coinciding with ideal (or non-ideal) environmental situations. The author of the post you cited is accurate to say that evolution is not an engineer, working towards a goal. The only goal of evolution is "What maintains life?" It's merely millennia of trial and error, and occasionally calamities occur, causing extinctions and loss of genetic potential.

I really think ANY characteristic of any species you care to name could be considered a result of evolution's limitations.

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The term you are looking for is evolutionary baggage.

An easy example is the crappy color vision in humans, for a long time mammals were only small nocturnal insectivorous or at least that is all that survived), during this time mammals lost two of the light sensing pigments in cone cells, leaving only two, primates had a strong enough pressure that a mutation creating a new pigment was favored giving use three, however two of them are very close to each other and overlap, and a whole portion of the spectrum is still invisible to us (ultraviolet) but non-mammals can see it. Birds see colors everyday you and I will never see.

Another mammal example is we turned the gene that would let us keep growing new teeth into control genes that give our teeth complex shapes, which was an advantage to our ancestors who were tiny insectivores, but now mammals can just grow new teeth to replace old ones like everything else can. there is no way to get these genes back without re-evolving them from scratch or giving up genetic controls on tooth shape, the first is simply to unlikely to occur and the second would be too detrimental.

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