If there's unconscious evolution why didn't human beings with major differences like 8 fingers evolve?

Question

Examples:
Why aren't there people that can run very very fast?
Or with an eye at the back of their back?
Or a human race like elves, dwarves?
Or a human race that can smell or see extremely well?
Or people that see black & white?

Reference points:
1. No one can claim that having 6 fingers is weak against evolution.
2. All our differences are minor, like color, shape of body parts, minor differences in perception etc.

Answer 1

Changes in the evolution proses are very small spread in a HUGE amount of time.
These changes to give an advantage, that's why you have bark skinned people in the hot areas of the planet, slanted eyes for the people that live in the North pole etc. etc.

Answer 2

There are many problems with your argument. I'll start with your two points, and add a few:

1. "No one can claim that having 6 fingers is weak against evolution."
You just assume this is true without really thinking about it. You have to show that 6 fingers would be a *distinct* advantage in the environment in which humans evolved. More fingers would be great for playing piano or typing, but there weren't a lot of pianos around in the Pleistocene savannahs. You have to show why a 6th finger would provide enough advantage that people with 6 fingers would survive better or reproduce in bigger numbers.

2. "All our differences are minor, like color, shape of body parts, minor differences in perception etc."
Precisely. That is part of the assumption, and evidence, for natural selection, that individuals in a population vary within a range. If "conscious" 'design' was happening, then individuals would be having *radically* different 'designs' that skipped any intermediate steps.

Even so, there is more variation within the human population than you might think. We live in a culture with very little tolerance for things outside the norm People are born with sixth fingers, or a tail, or ambiguous genitalia all the time, and we "correct" these things very early. Before medical remedies, we just called these poor people "freaks", and they either stayed hidden, or were trotted out for people's entertainment. But, yes, you're not going to see a lot of radical new mutations at the local mall.

3. Sometimes a structural mutation is just not possible because it requires *many* structural differences. A single mutation can produce a 6th finger. But to go from 5 fingers to 8 would require such a fundamental restructuring of the hand (bones, muscles, nerves) that the resulting extra fingers would most likely be useless.

Likewise an eye in your back would require more than a single gene mutating, it would require a total restructuring of the back, and a rewiring of the spinal cord and visual system for it to work. Genetics can't work that way.

4. Even if evolution was unable to explain why these development can't happen, you have to show how another theory CAN explain it better.

If designs like 8 fingers are truly *better*, then your question produces an even bigger problem to "intelligent design".

And if you are just promoting the "God works in mysterious ways" or the "in God's image" hypothesis, these are not much of an explanation.

5. There has been a community of people that see black & white. See "The Island of the Colorblind" by Oliver Sacks, about an island in Micronesia with an abnormally high number of cases of achromatopsia (total color blindness). This has turned a large part of their culture into a nocturnal one (e.g. they fish at night, and paint their houses all in neutral colors).

And as for a community of very short people, have you not heard of the pygmy cultures of central Africa. Or the species Homo floresiensis (which has been nicknamed "Hobbit" because of its short stature)?

If you're talking actual elves and dwarves, are you talking the Tolkien kind, or Germanic fable kind, or English folklore kind only a few inches tall? Do you mean pointy ears, ability to talk to animals, and maybe a few magical powers? Please be specific.

Again, evolution requires (a) something that genetics can do by mutation; (b) some reason for the isolation; (c) some distinct advantage that selects for certain traits.

Answer 3

1) It takes many times to change in a good way. Most of the mutation are bad for us.
2)Actually we are different from our ancient. very different
3)Do you think if you can run very fast It can help you to live and have a large number kids? It just help you to fry more fuel. evolution needs two things : 1)mutation 2)natural selection where is the force of natural selection in your ideas?
4)It has a evolutionary reason not to see black and white
5)having 6 fingers is not weak but it don't get you any advantages so we have some people who have 6 fingers.

Answer 4

There are people with 6 fingers. The condition is called polydactyly. The problem is that the extra finger (or toe) is often, but not always weaker than the other fingers because the nerves and muscles don't always develop correctly.

There are also people with 4 color receptors rather than the usual 3: They are called tetrachromats. There are also people with no color receptors that only see in black and white.

Physical stature (size) is more related to diet than genetics, but , again, there are races that are shorter or taller.

They eyes in the back of the head is developmentally not allowed: the regulatory proteins don't do that. Some people do smell better (ever been around a pregnant woman?).

I think you don't realize the amount of variation that exists in human populations.

Answer 5

Because there is no advantage to these changes. There does not need to be a disadvantage to them for natural selection not to operate - without an advantage to a mutation there is no way for it to propogate through a species.

And many of these changes would indeed have very undesirable effects.

For instance, high speed and high stamina are mutually exclusive. Hence a wilderbeast cannot run faster than a cheetah but CAN run much, much longer. As a result, cheetah attacks are only successful about 1 time in 10.

I could go on.

Answer 6

Evolution has designed us to suit our way of living. It didn't happen overnight! It has taken millions of years for us to evolve into what we are today and we are still evolving. We only have four fingers and a thumb because if we had more fingers we woudn't be able to grasp as effectively. We lost our tails as they were of no use once we stood straight and walked. Our senses of hearing and smelling are weak compared with the strength that we would have had thousands of years ago. This is simply because we don't require sensitive hearing and smell. These senses were used when, like all wild animals, we had predators. We had to rely on smell and hearing to hunt for food and to avoid danger. Today, we neither hunt nor have the danger. Colour is defined by the sun. The closer to the Equator, the darker the skin, hair and eyes. The further from the Equator, the lighter the skin, hair and eyes. This is simply because the more sunlight and the stronger it is, the more protection we require. As for elves and dwarfs, have you never heard of "Pygmies"? They are tiny little savage men. Finally, the eye on your back? Sorry, but when we run, we run forwards and need to concentrate on what is ahead of us. Maybe, we could develop a head like a chicken, with eyes in the side of our head so we can easily see 360 degrees.

Answer 7

Just a few additions to the excellent answers already here:

Even if 6 fingers was a minor advantage in terms of manual dexterity, there could still be selection against the trait due to sexual selection. Most critters tend to prefer mates that look more or less like themselves. Those that vary radically from the norm are generally less successful at mating, creating a stability of form that persists in a population that doesn't have extraordinary natural selective pressures (this contributes to the equilibrium portion of Gould's punctuated equilibrium).

Also: if fatgirl really does have a MSc in Cell Biology, then I weep for the quality of the American education system.

Answer 8

It is in the genes. The engine of evolution is genes. If it were genetically successful to have additional fingers, the frequency of that trait would increase. Of course you have to have help from humans. People with these oddities would have to mate. Therefore reducing the randomness of such oddities. They would start their own little tribe of 8 fingered people. Now how long and how successful would that be?

We are as we are because our genes make us that way. Thanks to your parental lines. Over a long long period of time.

These oddities are not race specific, like dwarfs. That's a mutation. There was a time when many dwarf died as infants. The reason we see more dwarfs is because medicine and human kindness is keeping them alive and dwarfs are getting together and having more dwarfs.

Humans don't have enhanced sense like other animals. We learned to use our brains to figure things out. We learned what a threat is and how to handle it. Humans learn to over come fear. Humans learned cooperation. Humans learned to make tools.

There are NO weak points against human evolution. Homo sapiens var. are the most succesful species on Earth. That says it all. At one time these minor differences, like skin color, had real purpose. They dont now because we humans have learned to control our environment. Who knows, skin color may become important again. We don't know how the human race will survive the next world wide catastrophy.

Answer 9

Some lizards have prehensile hands and feet with only one opposing projection.
This suites them perfectly for what they are or need.
Mans vision is excellent for their purpose,stereoscopic,sound alerts them to something from behind.
Size is optimum for man to survive between 3 and 8 feet has let them outlive many species.
You need 4 legs for fast running and you need fast running when you can't protect yourself any other way.
Seeing color allows you to see more without requiring motion.
5 fingers seems adequate,2 may have been not so good.
If you think 8 would be better,why not 20 or t30?

Answer 10

Maybe they did - but they were so butt ugly they couldn't pass on their mutations.

Or maybe the mutations were not exclusive and other things went wrong too.

Or maybe blind hunter gatherers ate poisonous berries and deaf ones got caught by the big cats.

All our differences evolved in a mere few short 10's of thousands of years - they recokon a few hundred survived the mega volcano erruption and that we can all trace female mitochondrial genes to just 3 prime females.

So maybe many of the mutation you are looking for came and went.

I do hope your not suggestion that evolution is all stuff and nonesense just because you can't see mutants at the local mall or in church?