Leonardo Pisano, better known as Fibonacci, was an Italian mathematician (someone who studies math) who conducted experiments relating to this special series of numbers in 1202. Although mathematicians in India knew about this sequence before he did, Fibonacci is credited with making it popular around this time.

His experiment was based on breeding rabbits. He wondered how many pairs of rabbits could be produced from a single pair of rabits in ideal conditions.

The first assumption of the experiment was that female rabbits always give birth to one male and one female bunny (which is not true in real life). The second assumption was that rabbits do not reproduce in the first month.

• Start with one pair of rabbits
• The second month would only have one pair because they would not reproduce
• The third month would have two pairs
• The fourth month would have three pairs
• The fifth month would have 5 pairs

The Fibonacci sequence is: 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144… to infinity. To find the next number, add up the two previous numbers.

Golden Spiral
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Look at the array of seeds in the center of a sunflower and you'll notice what looks like spiral patterns curving left and right. Amazingly, if you count these spirals, your total will be a Fibonacci number. Divide the spirals into those pointed left and right and you'll get two consecutive Fibonacci numbers. You can decipher spiral patterns in pinecones, pineapples and cauliflower [or brocolli] that also reflect the Fibonacci sequence in this manner.

Some plants express the Fibonacci sequence in their growth points, the places where tree branches form or split. One trunk grows until it produces a branch, resulting in two growth points. The main trunk then produces another branch, resulting in three growth points. Then the trunk and the first branch produce two more growth points, bringing the total to five. This pattern continues, following the Fibonacci numbers. Additionally, if you count the number of petals on a flower, you'll often find the total to be one of the numbers in the Fibonacci sequence. For example, lilies and irises have three petals, buttercups and wild roses have five, delphiniums have eight petals and so on.

Take a good look at yourself in the mirror. You'll notice that most of your body parts follow the numbers one, two, three and five. You have one nose, two eyes, three segments to each limb and five fingers on each hand. The proportions and measurements of the human body can also be divided up in terms of the golden ratio. DNA molecules follow this sequence, measuring 34 angstroms long and 21 angstroms wide for each full cycle of the double helix [source: Jovonovic].