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I'm trying to understand more about evolution theory. (I am coming from a mathematical background)

What i understand till now is that the "improvement" of the dna is a purely random development and the Selection criteria if the improvement was not negative is by surviving.

The better the improvment was the higher the likelyhood of surviving is.

What i don't understand is that the likelyhood that something useful comes from random changes in the dna is very low?

This reminds me of the http://en.wikipedia.org/wiki/Infinite_monkey_theorem it has surely a finite likelyhood but considering the complexity i still doesn't understand how for example wings of birds evolve.

Consider a pre-bird without wings, to get wings it has to have interstage with some useless pre-wings and then it has to learn how to flight.

Maybe someone can help me solve these mysteries :)

The other thing i am wondering is the smallest living element is the cell. How did the first cell evolve?

Thank you very much

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closed as too broad by Bez, Remi.b, Cornelius, WYSIWYG, Armatus Jul 31 at 17:33

There are either too many possible answers, or good answers would be too long for this format. Please add details to narrow the answer set or to isolate an issue that can be answered in a few paragraphs.If this question can be reworded to fit the rules in the help center, please edit the question.

    
This question has a large answer but in short, mutations occur at a certain rate, which can depend on the environment and how exposed organism is to mutagenic factors but there are intrinsic mechanisms for creation of variation such as SNPs and chromosomal crossover. Many mutations don't have any negative impact on survival (more importantly passing your genes). The ones that do will get selected against but the ones that increase chances of survival will remain and tend to become prevalent amongst the species over time. Cell is the smallest living unit in an organism. Look at the RNA world. –  Bez Jul 31 at 16:56
    
Your two questions (1. How can useful features initially evolve, 2. How did life start) are two of the largest debates in biology, with endless arguments going back and forth throughout academia and laydiscussion. It's not currently possible to definitively answer either of them, and people have written entire books trying to summarise the state of the debate at that time. Google these to your heart's content - some keywords of potential interest include "origin of life", "intelligent design" and "RNA world" - but unfortunately Bio.SE is not a suitable platform for discussing this. –  Armatus Jul 31 at 17:38

2 Answers 2

Welcome to BiologyBeta.SE!

On stackExchange sites, an OP should always limit his/her post to one question and should make his/her question is not too broad. But before you split up your question I invite you to have a look to some other post that will give you some answers. For this reason your question will very likely get closed as too broad. But I am giving some indices below. Also your post is a bit poorly written. This also lead people to close posts. Please come back with better posts, show some efforts in seeking for some information and it will be my pleasure to help you!

Origin of life

There are already a bunch of posts on the origin of life for example. Note that the origin of life is not a field that is part of evolutionary biology as evolutionary biology only explain the evolution of life and not its origin. As a mathematician you may prefer saying something like the domain of definition of evolutionary biology does not include the origin of life just like the shannon's theory of information says nothing about the euclidian geometry.

What i understand till now is that the "improvement" of the dna is a purely random development and the Selection criteria if the improvement was not negative is by surviving

Hum… that's sounds very weird. If I didn't know I would hardly recognize that you talk about evolution. You should have a look to some introduction to the field. Also, you should not confound the concepts of evolution, natural selection and mutations that I guess you confuse. A good, extremely simplistic view of evolution is that mutations occurs and create variance in the population. This traits are heritable. The variants that replicate the best increase in frequency in the population while the other variants will decrease in frequency up to the point to disappear. This is called natural selection.

Consider a pre-bird without wings, to get wings it has to have interstage with some useless pre-wings and then it has to learn how to flight

You also seem to ask a question about how some traits may come to exist while what seem to be necessary intermediate would not be beneficial. This question has been answered probably a thousands of time as it is a common creationist argument.


Because your questions really sounds like creationist arguments I am a bit afraid that you are not trying to understand evolution but you wondering whether evolution does occur or not.

Note also that evolutionary biology is a very big field. You cannot expect to have a more or less good understanding of the whole science of evolutionary biology in less than a year. But if you are trying to just understand the very basic, sufficiently to persuade you that evolution does occur, then few weeks will probably be enough if you show some effort Please don't forget the questions you may have. Seek by yourself for more knowledge and if you can't find something, then you're really welcome to come back to this site with an accurate question.

EDIT

Have a look to the definition of scientific theory. Also, please read @Chris comment below.

You misunderstand the meaning of "direct observation" that canadianer used. Observations we do in evolutionary biology are just as valid as those that has been made to confirm the theory of gravity. The only point concerns the easiness of understand these observations for non-literate in the field.

Yes, you are totally right. Just like the theory of gravity, the theory of evolution does not explain everything. It only applies to a subset of the phenomenons existing on earth. The theory of evolution is true, we know for a fact that evolution occurs but our theory is not global enough to explain things like the big bang or the surface tension and will never do so. The theory of evolution will never prove or disprove the existence of God as well (supposing you're concerned about that) because again it is not within its scope and will never be. However, the sociological impact of this theory tells much about the human behavior and our difficulties to accept something we know to be true if it contradicts some pre-establish believes even when these pre-established believes are not based on any logical developments.

Your question has been closed because it is too broad. The issue also is that your questions concern much more than evolutionary biology and biology. It also concerns the very nature of science and this is a common reason why creationist missundestand evolution. They don't (only) missunderstand evolution but they missunderstand what science is.

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thank you very much. That intermediate changes might have some other function is something i did not thought about, but it sounds reasonably. I want to understand Evolution-theory more because i have the feeling i have no idea about it. In mathematics i learned that asking the critical question leads to far better improvement than looking at the obvious examples and that is often the point where some of the "theories" fail. And in my personal opinion as long as something is not proven (might be never the case) you should always look at the critical points without the bias evo is true/false –  jonsonBen Jul 31 at 19:04
    
Direct observations of populations changing were and are made and then the theory of evolution was created to describe the process. There is no debate about evolution being true or false. What you're saying sounds the same as watching an apple falling from a tree, creating a theory of gravity to describe it and then having a debate about whether apples falling from trees is true or false. –  canadianer Jul 31 at 20:23
    
why is it then called theory? –  jonsonBen Jul 31 at 20:59
    
to make your comparison more correct i'd would say it's more about if the theory of gravity is right/wrong. While Newton's Law is true it is only partial true as an approximation for a more general law. (and Newton's Law was discovered through Direct observations) So maybe even while Evolution seems to be true it might not explain the picture fully. –  jonsonBen Jul 31 at 21:18
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@jonsonBen Just because it is called theory, it doesen't mean it is theoretical and can not be proven. The opposite is true. A theory describes the theoretical foundation of a special part of science. As does Newton with its theory of Gravitation or Einstein does with its Theory of Relativity. What you are looking it is the term "hypothesis". This can be proven wrong or right. If the first is true, scientists set up a new hypothesis to work with. Standard procedure, no drama included. –  Chris Aug 3 at 20:42

What i don't understand is that the likelyhood that something useful comes from random changes in the dna is very low?

Well, in that most changes are neutral, sure. But EVERY organism on the planet has mutations. It doesn't matter if the odds are low. If you have billions of organisms in a square meter of soil, how likely do you think it is that not a single mutation in a single organism will be beneficial in that environment?

Consider a pre-bird without wings, to get wings it has to have interstage with some useless pre-wings and then it has to learn how to flight.

Ah, another Creationist who thinks that the universe can not possibly contain anything that s/he can not personally imagine. There might be uses for intermediate structures that you just can't think off off the top of your head (like gliding). There might be intermediates paths that you just can't think of. There might be other structures that worked in concert with the intermediates, and then faded away as things changes, much like you build an arch with a scaffold, and then remove the scaffold. Just because you personally can't imagine the possibility of a scaffold doesn't mean such things are literally impossible.

Have you even tried googling "bird wing evolution"?

The other thing i am wondering is the smallest living element is the cell. How did the first cell evolve?

Come on. That's a completely different question. Surely someone who thinks they understand the problems of evolution better than professionals who have studied the data for years know that lipids spontaneously formed closed cells, right? And knows that RNA can autocatlyze reactions, yes?

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