Darwin's suggestion anticipates phylogenetic bracketing, a method based on that uses characteristics of organisms in a clade to make predictions about the common ancestor of the clade and all of its descendants.

The carbon cycle is best defined as a process in which a. carbon changes from inorganic forms to organic forms and back b. carbon is changed into other elements such as oxygen or nitrogen c. carbon is continually created from the sun’s energy by plants d. carbon is consumed and regenerated from other elements such as oxygen and nitrogen