Core architecture of the body encoding [closed]

Question

First of all, I am not a biology guy; I am in Computer Science. But, I have a strong interest in all the mysteries of nature, from universe to human body. So, I want to ask a question related to genetics.
As I have read that all(both male's and female's) the biological traits of a person are passed genetically to the offspring(of course assuming the crossing). So if my mom's eye color is blue and my dad's eye color is also blue, I will get blue color too, but what about the core architecture of the body? I mean I have 2 legs at a certain location from my body(my waist but, not from my head!) and similarly other orientations.
Why they are that certain way? If they somehow got changed, would the resultant body be stable?Is the answer different in case change is artificially engineered or natural?
Where is this core architectural information exactly stored(If the answer is DNA then how?) and in what form is it stored?How come that information is not changed in thousands of years or even millions of years? And is that information of such nature that it contains "exact" steps to develop a healthy say, brain structure(which is a really complex)?
My another question is: If there is a community of mutated people, will their offsprings be mutated always with 100% certainty?

I know these are a lot of questions but you can see that, they basically revolve around the information that I am curious about. Can someone address my curiosity?

Answer 1

Welcome to Biology.SE!

Your question is very broad. Also, your post has the default of containing severals questions in it. Make sure in the future to restrict your post to only question, it will be much more likely that you receive a good answer then. I hope that I can give some indications about how to get some more knowledge in this answer. In this answer, I do not consider all your questions one by one to answer them (or guide you to the answer) but I think that all your questions will get an answer as you learn more about the subjects I cite. Hope that answer will help you.

Very basics of molecular genetics

You should start to have a few ideas about genetics. Make sure you know what is a chromosome, a gene, an allele, a protein and a phenotype. Wikipedia will help you with that. Come back on Biology.SE if something seems unclear to you.

Basics of genetics and evolution

You are definitely interested in concept of segregation. This is a very fundamental concept in genetics. The basis of the laws governing segregation has been first discovered by Gregor Mendel and we still name these basics laws after Mendel. We talk about Mendelian segregation. You may want to google that.

Then you are interested in the concept of heritability. I have been talking about heritability in different posts. In the third sentence of my answer here, there is a short list of posts that define the concept of heritability.

Eye color you said?

You talked about the genetics of eye color inheritance. Here is a post that will interest you then.

The Genetics of Development

Your question is not only about genetics but is about the genetic of development. You may want to have a look to the basics of developmental biology. The most famous DNA sequence involved in determining the body plan of many different living things are the so-called homeobox. There is plenty of interested things about this homeobox. This post may interest you btw.

Rough details about the evolution of development along the tree of life

How come that information [architectural information] is not changed in thousands of years or even millions of years?

It really depends on what you call architectural information. But in any case it does evolve. If you think of things such as like size of an animal. Then it may evolve fairly quickly. You may thing of more important change, such as evolving a new pair of legs or evolving wings or a head, then it tends to take more time. Below are just a bunch of examples of how animals differ in terms of body plan along the tree of life.

You might be interested to study a bit the development or early animals. Some have a radial symmetry while other (like us) have bilateral symmetry (see wiki). Some animals have a head, some don't. Some animals have two dermes while others have three dermes. The Deuterostomata (vertebrates, tunicates, echinodermes, ...) have a development where the blastopore of the gastrula becomes the anus while in the protestomata (now thought to not be monophyletic and divided into ecdysozoa and lophotrocozoa (see here)) the blastopore becomes the mouth. Among the arthropoda (insects, spiders, millipedes, ...) the story is very interesting as well. Some have a highly segmented body with a pair of legs at each segment (millipedes) while other groups have fused those segments. Spiders have only two big body parts, while insects have three big body parts. In insects, the thorax (one of the 3 body parts with the head and the abdomen) contain three segments and each segment hold a pair of legs. The first flying insects also had three pairs of wings, now degenerated into two and even into one in Diptera.