A Level core biology question

I really need help with my core biology , please see below the question i need help with . Using your knowledge of meiosis and the passage below, explain why there are so many different human skin colours. Inheritance of skin colourThe theory that characteristics showing continuous variation could be due to the combined effects of many genes was suggested in the early20th century, but little progress was made during rest of the century in identifying the genes involved. Skin colour in humans is an interesting example. A study published in 1964 of families in Liverpool that had both African and European ancestors suggested a minimum of three or four genes affecting skin colour, but much larger numbers of genes could be involved. Mutations of several genes are known that can prevent melanin production completely, leading to albinism, but genes varying the amount of melanin production are required to explain the observed continuous variation in humans. A mutation of a gene called SLC24A5 has been discovered that causes paler skin and accounts for more than 25 per cent of the variation between European and African populations, but the remaining variation must be due to other genes. When these have been discovered, it will be possible to say exactly how many genes are involved in this example of polygenic inheritance. (Advanced Genetics OUP)