EVOLUTIONARY TREES

Page from Darwin's notebooks around July 1837 showing his first sketch of an evolutionary tree

Evolutionary Trees• Diagram that reflects the evolutionary relationships among groups of

organisms• HYPOTHESIS – summarizes our current understanding of evolutionary

relationships between living things – both extant and extinct; testable• EVIDENCE BASED – anatomy, biochemistry, fossils etc; the more data

sets that support the tree the more confident we are that we are correct• SCIENTIFIC MODEL - testable idea created by the human mind that

tells a story about what happens in nature; a description of nature that can predict things about many similar situations - The value of a model is that we can trust its predictions about similar situations even if we don’t encounter each situation; a diagram, an equation, a physical model, etc.

ANY QUESTIONS?