He later tried to justify his comments by saying he talked about the number of Muslim prize winners because we often hear "boasts about their total numbers".
He added: "A statement of simple fact is not bigotry."
Dawkins has gained worldwide attention for his outspoken criticism of organised religion, and argued that the September 11, 2001 attacks on the United States showed that a harder line must be taken with believers.
In 2010, he sparked controversy after labelling the Pope "a leering old villain in a frock" in an article for the Washington Post. He has also called the Catholic church "evil". Previous Twitter comments have also caused a stir, including: "Don't ask God to cure cancer & world poverty. He's too busy finding you a parking space & fixing the weather for your barbecue."
This year, he called those who burned down a library in Timbuktu, Mali, "Islamic Barbarians".
His comments were interpreted as being derogatory to Islam and insulting to followers of the religion by some on Twitter.
Trinity College, Cambridge, has 32 Nobel laureates, as against 10 Muslims listed in Wikipedia.