How many genes created the different finch beaks?  

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gsenviro eNotes educator| Certified Educator

Darwin's finches are a number of species of finch found on the Galapagos Islands that shaped his theory of evolution. During his famous visit aboard the H.M.S. Beagle, he found that finches have different beaks, even though they are the same type of bird. Some finches have longer pointed beaks, while others have thinner beaks. 

Scientists have now found the gene responsible for this variation in beak shapes. It's interesting just one gene is responsible for this variation. This gene is known as ALX1 and is commonly found in human beings as well. Based on genetic studies on a large number of finch samples, scientists have found that this particular gene may be somewhat different between different individuals of the same species and this causes differences in beak shapes.

It is to be noted that Darwin observed that different beak shapes are suited to local foods, available on that particular island. These results clearly show that genetic variation is a key to evolution. 

Hope this helps.