Evolution Question?

Question

Im no biologist and don't knwo alot about evolution. I read somewhere that its caused by a random mutation in an animal and then that animal has a better chance to survive

But to me it makes more sence that an animal already has the potential to mutate and change their DNA acording to the environment around them and not do it randomly but because of whats happoning aroud it at the time

If its random mutation why are for example black and white people? its obvious that black skin helps Africans survive in the hot country they live in but its not like they would die out if they had moved to a different continent

We all had to start off as one colour rite? i just can't imagine black people going to a cooler climate and then slowly all the dark skined people dying out

It makes alot more sence to me that humans evolve to their environment and not that humans mutate and then the environment chooses who survives, am I completely off here?

I mean is there scientific proof that DNA can change based on how a person lives their life?
Like if a person say gets a tan every day, will that alter their DNA slightly or not? Or if a person drinks lots of alcohol will that alter their DNA slightly if at all?

WTF? I asked this question in Biology to specificaly avoid religious answers, please no more, evolution is bullshit, ask god answers

im not christian and never will be, i can't follow an egotistical religion that believes that everyone apart from them is going to spend eternity having their skin shaven from their bones and their eyes plucked out no matter how good a person they are, and no matter how many little boys the christian malests

Answer 1

I think Christianity has nothing to do with evolution. This is the biology section, so let me answer this in a biological way.

Yes, you are right that if an animal has the potential to control their own DNA and mutate according to its environment, they would be much better adapted! However, you need to think of a mechanism to do this. The thing is, there is no mechanism for us to control our DNA. Random mutations is what happens in this world, simply because DNA replication is not perfect. While DNA polymerase can check the duplicated sequences, they make 1 mistake in a couple billion nucleotides (if I remember correctly). Considering that our entire genome consists of 3 billion nucleotides, it is not that amazing to assume our DNA is changing, and that if these changes occur in our gametes, our children will have some genes that are different from our own. In other words, humans and all other species are constantly changing due to these random mutations.

Why are there black and white people? Well, let's say black people came first (because mitochondrial DNA suggests that all humans descended from Africans). Imagine there are some people with random mutations that cause them to become white. White people interbreed, and the resulting population is white. This is not a matter of the fact that Africans can survive in another continent or whatever, it is just that in the past, black people interbreed separately from white people, so there is two distinct populations. With interbreeding, doesn't the skin color change as well? Besides, skin color is not wholly dependent on DNA. Our DNA sequence codes for production of pigments that respond to environmental signals, meaning that if you are in the sun, your skin color changes. However, what gets passed down to your offspring is your genes, not how you look like now. That is to say, even though you are tanned, your baby won't be born tanned. That's sort of obvious, right?

Once again, what do you mean humans evolve to their environment by non-random change? You need to suggest a mechanism for us to do so before I can answer your question. The reason why it is random is because that is the only means of DNA change. There cannot be non-random DNA change as far as we've seen in science. We can't go like "I want TACATGCTCAAAATC as my gene". If that's the case, we could all be Eistein, if not smarter. Maybe further down the road with evolution choosing for those with greatest fitness, there will be a species that can evolve in a non-random manner, choosing which segment of DNA would be best suited for their environment and be able to change it as much as they like. But as we still aren't such an advanced species, natural selection is the best mechanism for the evolution of better species.

And on your latest edit:
Yes, there is scientific evidence that lifestyle can cause different degrees of change in DNA. The change will still be random, but more change can be induced. For instance, there is an obvious link between lung cancer and smoking. Smoking obviously induces DNA change because cancer is caused by DNA change. For your information, scientists can choose mutations but inducing natural selection on bacterial colonies. They put in a bunch of stuff that mutates DNA (like UV light), put the colony in a plate of antibiotics, and the resulting bacteria that are capable of surviving the conditions carry a mutation for antibiotic resistance.

One last note:
Evolution is a very good theory. It can explain many things about science, that is why it is still so widely used today in so many scientific disciplines. Evolutions does not contradict with religion. There is little connection between the two anyway. We did no evolve from apes, but rather, apes and us share a common ancestor species that is extinct now through speciation. Apes are equally adapted to their environment as we are to ours, so by no means are humans the most evolutionarily advanced race and that other animals must not exist by natural selection or whatever those theories that twist evolution and calls it evolution say. A final remark is that nothing in science can be proven. It can only be supported or refuted because the next thing around the corner may disprove any theory, no matter how good it is. Evolution is the most widely accepted theory for the origin of species to this date, but by no means can anyone say there is a 100% chance that it is right, because every single scientific theory out there is just based on what we humans can observe. Perhaps something that we cannot observe would disprove everything that we know.

Answer 2

You are thinking along the right lines, but...

*All* animals have the potential to mutate; mutation is a change in the organism's DNA, and all mutations are random. However, some mutations will be bad, some mutations will be neutral (no change in the organism's ability to survive and reproduce), and some mutations will be positive.
The environment puts a *selective pressure* on the organisms, such that those with the "good" mutations are more likely to survive and reproduce. So, after a few generations, their genes (including the beneficial mutation) will be more common in the population.
Think of it this way: if one organism has a mutation that means that it is twice as likely to survive to reproduce than all the others in the population, then it's going to have (on average) twice as many offspring as all the others. Since the offspring will inherit the trait, they will have twice as many offspring, and so will their offspring ... and so on. Pretty soon, instead of just one individual with that mutation, there will be hundreds - and the population as a whole will have *evolved*.

For skin colour in humans, no-one is 100% certain, but one idea comes from how humans obtain vitamin D. Vitamin D is made in the skin, by the action of sunlight.
In africa, there is no problem making vitamin D, because there is lots of sunlight; in fact, there is so much sunlight that black skin is good, because the melanin (the actual black pigment) protects your skin from UV light and skin cancer. But, if you move away from the strong sunlight of africa, then the problem becomes getting enough vitamin D, because the melanin also shields against the vitamin D production by action of sunlight. So if you have lighter skin, you won't get skin cancer (because the UV light isn't strong enough), and you'll be able to make enough vitamin D to avoid getting a deficiency. So individuals with a mutation giving them paler skin become more and more common, and eventually, you have almost no dark-skinned people in more northerly latitudes.

PS - some "lifestyle choices" will have an effect on the amount of mutation. Carcinogenic conditions like lots of sunlight will increase the liklihood of mutation (though only in the cells actually bombarded by the UV - the skin cells). Alcohol isn't really a carcinogen/mutagen, so it won't have much of an effect.

Answer 3

What you are proposing is Lamarckism, the inheritance of acquired characteristics. Before Darwin many people thought this might be possible, but as it turns out evolution doesn't work that way.

In every population of living creatures, there is a constant level of mutations going on all the time by means of copying errors in their DNA and chemical and radioactive damage, also to the DNA. These errors get passed along to the offspring, making them slightly different from their parents (only identical twins look just like each other but neither looks just like their parents).

Most mutations are harmful and give a disadvantage to the individual that suffers from them, making it less likely they will reproduce and pass it on to the next generation. A few turn out accidentally to be advantageous in whatever the current environment happens to be, and nature will favor those with such mutations.

This has been observed many times in fruit flies and smaller creatures, but also quite spectaculary in, of all places, the Galapagos Islands themselves. Some researchers living there for many years noticed when the weather changed over a long period the birds on this island gradually developed different beaks to suit the change in the food supply!

The beaks did not change under the influence of the new climate - the new climate favored the retention of mutations that produced the new kind of beaks. Remember that mutations are random and are either neutral, harmful or advantageous depending on the environment of the moment. If the environment goes back to what it was before the new beaks will no longer bestow an advantage (possibly even becoming a disadvantage) and will no longer be as common.

This beautiful mechanism has vast explanatory power and requires no supernatural intervention to work, much to the dismay of religious believers but to the joy of everyone else, since at one stroke it made sense of so much of biology.

It explained the emergence of new species as well. If part of a population becomes isolated from the rest and they cease to interbreed, genetic drift - the gradual buildup of random mutations - guarantees that at some future time the two populations will have such different DNA that they can no longer reproduce, making two species out of one (assuming the original group still exists, which is not 'impossible' as some fundamentalists would have you believe).

In point of fact, species will mutate into other species over time even if the original population remains intact. There won't be any remote ancestors left but it's a safe assumption that they wouldn't be able to breed with their present-day descendants if enough time has passed.

PS: Groucho is an ignoramus, confusing the fact of evolution (proven consistently for 150 years with millions of examples) with the explanation - called a theory in the scientific sense - of *how* it happens. Scientifically, theory does *not* mean 'educated guess' as it does in the vernacular - so you lose, Grouchy boy.

Answer 4

DNA does not change based on how we live our lives, this was a big contender once, called lamarckian evolution but it has since been thoroughly discredited.

In answer to the example you provide it is likely that the first humans has a mid - dark skin tone. Dark skin has more melanin which gives dark skinned people extra protection from skin cancer while light skin is more efficient at producing vitamin D from sunlight, a useful adaptation in cold drizzly European areas (not so great in the sun lol). All the black people didn't die out, what would have happened is that as people pushed further north out of Africa those with the palest skin simply lived longer and produced more offspring, therefore there was a selection pressure for pale skin and it became more and more common in these populations. The opposite happens with dark skin.

Answer 5

Well there have been a range of different approaches to explain how animals and plants came to be (but why was God so evil he created tooth decay).

Evolution is the only theory that really has any scientific credibility. Basically, it is about competition. For example, Imagine a population 50% white, 50% black, living in Europe. The black people suffer more from vitamin B deficiency so that next generation it is 60% white and 40% black...and so it goes until the whole population is white.

Do the same thing in Europe and you have more black people living because of skin cancer and you have the same genetic creep over a long period of time.

Answer 6

Evolution is not independent of outside stimuli. You are completely right in that we and animals adapt to our environment as well. Both mechanisms are at play and interact with each other:
- random mutations arise. If they confer a biological advantage, they get propagated further because more of those animals get to sexual maturity and live long enough to raise their children. During the Industrial Revolution in England, moths that were gray survived better because they were less visible in the dusty outdoors than the white moths.
- the environment can put selective pressure on biological beings and choose which beings survive. White moths got eaten because the gray environment better concealed the gray moths.
*on the moth example, which is the classic one, here's a semi-counterpoint that illustrates how complex the problem is: http://www.millerandlevine.com/km/evol/Moths/moths.html

The Wikipedia article is a good one as well...



On your new edit:
Your DNA is damaged everyday (that's where cancers come from), but since the DNA damage is limited and sporadic and random, you're unlikely to gain a positive or systemic trait from that change. On the other hand, babies in utero can certainly be changed by the mother's diet and exposures and experiences -- for example, there is a higher prevalence of Down syndrome in older mothers (and fathers) possibly because of accumulation of DNA damage.

Answer 7

1) According to evolutionists, Humans evolved from apes? Humans are apes by definition. Linnaeus classified us as such and he was a creationist. 2) There are many proven facts in science, but evolution is just a theory. False due to a misunderstanding of the word theory. A fact, in science, is a discrete point of information. Theories connect facts and explain them. There is no higher classification than theory. 3) A transitional form is a fossil of an animal that is part one species and part another. False. All organisms are transitional. 4) The age of the earth is determined by scientists solely through the radioactive dating of fossils ? The age of the Earth was determined by dating a meteor on the assumption that the Solar System was all the same age. All other calculations fit the age found. 5) The scientific method begins with a prediction and then looks for evidence to support that prediction? It begins with observation. Then a hypothesis is formed from that observation. After the hypothesis is formed, scientists look for evidence to support or falsify the hypothesis. 6) The theory of evolution includes the Big Bang? False. 7) To believe in evolution is to believe that life and matter came from nothing? False.

Answer 8

Wow. I guess no one is safe from the bible thumpers. (I'm not very knowledgeable about it but I don't believe it--Ha!)

Anyway, mutations occur randomly, and they add diversity to the gene pool. With sexually reproducing organisms, there is also a continuous "re-shuffling" or mixing of genes.

A "good" trait is one that gives its bearer a statistically higher chance of survival than if the bearer had not had it. A "bad" trait does the opposite. An organism may very well live and reproduce, or die and not reproduce due to other traits, or to natural disasters, etc.

But over long periods of time, a trait that increases the likelihood of survival will grow more numerous in the gene pool. Other random effects on survival will cancel out with large numbers.

In the case of skin pigmentation, darker skin means a smaller probability of getting sunburned, and getting sunburned could cause a person to die, if, for instance, they were competing for a limited amount of food or a sexual partner with a rival that was healthier. It could also increase the risks of infection through skin abrasions.

Bear in mind that we have to think in terms of peoples who didn't have access to modern medicine, and who didn't have governments to protect them from harm. The amount of time that modern civilization has existed is the blink of an eye on an evolutionary timescale.

Answer 9

Let's talk simpler bugs, the cockroach has evolved and will survive almost any attack, some including nuclear war.
The survivors from a nuclear war would have the genes that gave it resistance to the radiation. Some may mutate and survive but it would be a very small percentage and it's hard to say that the mutant would be viable in the long term as opposed to the natural selection from the survivors of the radiation

Answer 10

Mutation cannot occur in nature without happenstance. Because of this evolution is random. Just as an species can evolve into something "better" it can also evolve into something "worse".

The other possibility is that the mutations are controlled - by what or whom is unknown. This could be where religion and science intersect.