Common descent

Common descent is a scientific theory in Biology it can be applied on two levels, with a clad or group of species being said to share a recent common ancestor, or the broader theory which states that all organisms on earth originated from a single common ancestor. The theory is usually used in support of the Theory of Evolution.

Darwin wrote:

"When I view all beings not as special creations, but as the lineal descendants of some few beings which lived long before the first bed of the Silurian system was deposited, they seem to me to become ennobled."

Jonathan Wells in his book Icons of Evolution made the claim that many current biology textbooks use distorted pictures of vertebrate embryos to convince students that vertebrates share a common ancestor. (Wells) However, this statement has been heavily criticized by many scientists who have reviewed his book as being misleading in some cases and false in others. [1] [2]