Question: As we are all descendants of Prophet Adam A.S., I understood the explanation of Hawa A.S. giving birth to various sets of twins of different race and thereafter the marrying of the males to females of a different set to produce various race. However, i then learned we are all descended from Prophet Nuh A.S and that all other lineages had perished *(which is mentioned in this [answer](https://islam.stackexchange.com/a/2063/15201))*.

**Question:** If we are all descendants of Prophet Nuh A.S., why are we so many races?

Answer: 
Islam is meant to be for spiritual well being and attainment. Some may call it closeness to God and others may call it something else. Some, not all, Muslims (actually religious people in general) think that religion has the answer to every question. However, that is not the case. It has answers to most questions, especially, questions related to spiritual well being: This includes social and judicial laws since they are needed for spiritual well being. But it does not have answers for all question and this question is one of them. 

Answer to a question such as this will not be found in Quran or Hadith because it is outside the context of what Islam brings to this world. Therefore, for questions such as these, one should not depend on religion (Islam, Christianity, Judaism etc.) but depend on History, Science etc.

There are Muslims who would argue and say that Quran has answers to every question one can possibly have, and I am not disagreeing with them because they would point me to a verse such as [this](http://en.islamtoday.net/artshow-315-3185.htm):

> 
> If you can pass beyond the zones of the heavens and the Earth, then pass!
> 
> 
> 

which they claim speaks of travelling to space. Now whether they are correct or not is beyond the argument here. What I am trying to say is that sure everything in this world ties to Quran (if you are a Muslim) or Bible (if you are Christian) in some way but it would be foolish if one was to look inside The Holy Quran, or Hadith or The Bible to try and find how binary arithmetic works.

In conclusion, you will have better luck and a more informed answer if you were to ask this question on another site.
If we are all descendants of Prophet Noah, why do we have so many races?
In some narrations, the existence of differences in the color of the mud from which Adam and Eve were created, has been introduced as the cause of the difference in the color and race of human beings. The Messenger of God, may God bless him and grant him peace, was asked: ... Was Adam created from all mud or from a single mud? The Imam said: Of all the flowers, and if it had been created from a single flower, some people would not have known others (that is, they would all be alike).

A hadith from Imam Ali (as) has been narrated about the difference between human beings: “The reason for the difference between different people is their nature. Because from the beginning, human beings were a combination of salty and sweet soil, hard and soft ... one beautiful and short-sighted, another tall and low-minded, and one ugly and virtuous, and one short and well-thought-out, and one pure in nature and immoral. ... »

In some hadiths, the prayer of Prophet Noah (pbuh) is introduced as the cause of differences between races and colors. In the commentary of Noor al-Thaqalin, he narrates from Hazrat Abdul Azim Hasani: I heard Ali ibn Muhammad Asgari (peace be upon him) say: He prayed for them and said: خ "O God, change their crucifixion so that only black children will be born from their crucifixion ..."
But from the Qur'anic point of view, the will of God Almighty is that human beings are different in terms of color, race and shape. God, who is able to create man from inanimate mud, can make some of Adam's children black and some white, etc., for his personal and social interests. It is stated in Surah Al-Hujurat: "O people, We created you from a male and a female, and made you into great clans and small clans, that you may know one another."
And in verse 22 of Surah Romans, God Almighty expresses the difference of languages and colors as signs of His power.

Ref:<https://hawzah.net/fa/Question/View/65359/>