For thousands of years and in many cultures, the Tree of Life has been an icon of creation, a symbol of life and a map of kinship. Recently, scientists have revealed a Tree of Life that illuminates how all creatures alive today have evolved and share a common ancestor.
The Tree of Life shown here, presents a simple overview of how life evolved over time. This particular Tree of Life is based on the molecular code of life: DNA. Beginning with the origin of life over three and a half billion years ago, the lines on this tree illustrate how organisms have emerged, changed and disappeared over time.
Thee colorful and engaging pictures at top of the tree to represent the diversity of creatures alive today. The base of the tree indicates when life on Earth first appeared, over 3.5 billion years ago. Numbers along the side indicate the thousands of millions (billions) of years before the present. This tree is based on comparisons of DNA sequences from genes of thousands of diverse creatures. Humans, amoebas, strawberries and E. coli all share about 500 similar genes. (For comparison, humans have between 20,000 -25,000 genes.)