Stated plainly, biological evolution is the theory that explains the pattern of the tree of life as resulting from descent with modification from a single, common ancestor. Because the definition of evolution is change in the heritable characteristics of a population over generations, evolution can occur by means other than natural selection. Though not less controversial than the first ancestor, it is at least the subject of testable hypotheses. Examples of common ancestor in a sentence, how to use it. There is evidence of common descent that all life on Earth is descended from the last universal ancestor. Moreover, Darwin proposed that all of life on Earth descended from a common ancestor, via slow, incremental accumulation of heritable (genetic) changes. An ancestral species is a common ancestor because two or more descendant species share it as an ancestor.When we speak of a trait being identical by descent, generally we are referring to a common ancestor sharing that trait with more than one descendant species.. Biology Glossary search by EverythingBio.com The state of two individuals when they are blood relatives. Choose from 83 different sets of ancestor biology flashcards on Quizlet. (plural common ancestors) an ancestor that two or more descendants have in common The monarchs of Spain and the UK have a common ancestor namely Queen Victoria. (A related concept is that of progenote. ) A related concept is that of progenote. 20 examples: And is there one common ancestor for sauceboat, saucebox, saucepan, and saucy… The last common ancestor is more accessible to geology and molecular biology than the first ancestor. This stems in part from the continued misconceptions surrounding biological evolution. When two parents have a common ancestor their offspring will be inbred. Learn ancestor biology with free interactive flashcards. However, to the general public, the term “common ancestry” is rife with confusion. 8.01.5.3 The Last Common Ancestor. Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time. The last universal common ancestor or last universal cellular ancestor (LUCA), also called the last universal ancestor (LUA), is the most recent population of organisms from which all organisms now living on Earth have a common descent—the most recent common ancestor of all current life on Earth. In evolutionary biology, a group of organisms have common descent if they have a common ancestor. Biology. Common descent describes how, in evolutionary biology, a group of organisms share a most recent common ancestor. Dictionary.com Unabridged One from whom an estate has descended; the correlative of …