Chapter 2: The Evidence for EvolutionOverview |
The goal of Chapter 2 is to review evidence that supports an alternative statement of fact that Darwin called “descent with modification,” and that later came to be known as evolution. According to Darwin, species have changed through time and are related by descent from a common ancestor.
2.1 Evidence of Change Through Time
One of the central tenets of the Theory of Special Creation is that species, once created, are immutable. This claim is challenged by several lines of evidence that support the alternative hypothesis that populations of organisms change through time.
The data reviewed in 2.1 of your textbook comes from living species as well as from extinct forms preserved in the fossil record.
2.2 Evidence of Common Ancestry
In contrast to the Theory of Special Creation, Darwin’s theory of life’s history holds that species are not independent, but are connected to each other by descent from a common ancestor. This means that species have geneological relationships analogous to the family trees of individual humans.
Turn to section 2.2 of your textbook to learn the evidence supporting Darwin’s view, it will be worthwhile to spend a few paragraphs introducing the graphical technique evolutionary biologists use to think about the relationships among species.
By the time Darwin began working on the origin of species, data from the young science of geology had challenged a linchpin in the Theory of Special Creation: that Earth was only about 6,000 years old. Evidence was mounting that Earth was ancient.
Section 2.3 of your textbook tells the story of learning about our Earth’s beginning.
2.4 Is There Necessarily a Conflict between Evolutionary Biology and Religion?
We have discussed evidence that conflicts with the Theory of Special Creation, a view of life’s history derived from a literalist interpretation of the Bible’s Book of Genesis. And we have argued that this evidence is consistent with Darwin’s alter-native, the theory of descent with modification from a common ancestor. Does this mean that evolutionary biology is necessarily in conflict with Christianity or with religion in general?
Turn to section 2.4 to learn more about this challenging issue.