CHAPTER 13: THE ENVIRONMENT AND CHANGE OVER TIME

Lesson 3: BIOLOGICAL EVIDENCE OF EVOLUTION

?? Essential Questions What evidence from living species supports the theory that species descended from other species over time? How are Earth’s organisms related?

Vocabulary Comparative Anatomy Vestigial Structure Homologous Structure Embryology Analogous Structure

Evidence for Evolution Living species that are closely related share a close common ancestor. The degree to which species are related depends on how closely in time they diverged, or split, from their common ancestor.

Evidence for Evolution Comparative Anatomy is the study of similarities and differences among structures of living species Homologous structures are body parts of organism that are similar in structure and position but different in function

Evidence for Evolution Analogous structures are body parts that perform a similar function but differ in structure Vestigial Structures are body parts that have lost their original functions through evolution

Evidence for Evolution Developmental Biology The science of the development of embryos from fertilization to birth is called embryology

Evidence for Evolution Molecular Biology Comparing Sequences: Scientists can study relatedness of organism by comparing genes and proteins among living species Divergence: Scientists have found that some stretches of shared DNA mutate at regular, predictable rates

The Study of Evolution Today The theory of evolution by natural selection is the cornerstone of modern biology How New species Form: scientists debate some of the details, further fossil discoveries will help scientists study more details about the origin of new species Diversity: How evolution has produced Earth’s wide diversity of organisms using the same basic building blocks (genes) is an active area of study in evolutionary biology

Classwork Page 487 #1-9 Write down questions and answers Workbook page #416-147 and 423