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KEY CONCEPT Evidence of common ancestry among species comes from many sources. NGSSS.
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KEY CONCEPT Evidence of common ancestry among species comes from many sources.
NGSSS • SC.912.L.15.1*Explain how the scientific theory of evolution is supported by the fossil record, comparative anatomy, comparative embryology, biogeography, molecular biology, and observed evolutionary change. (HIGH)
Evidence for evolution in Darwin’s time came from several sources. • Fossils provide evidence of evolution. • Fossils in older layers are more primitive than those in the upper layers.
island species most closely resemble nearest mainland species • populations can show variation from one island to another • The study of geography provides evidence of evolution.
Larva Adultbarnacle Adult crab • identical larvae, different adult body forms • similar embryos, diverse organisms • Embryology provides evidence of evolution.
Comparative embryology: Similar embryo development in closely related species
Molefoot Batwing Human hand • Homologous structures are similar in structure but different in function. • Homologous structures are evidence of a common ancestor.
The study of anatomy provides evidence of evolution. Homologous Structures: Same underlying structures, different functions, different environments & common ancestor Bird Wing Porpoise Flipper
Comparative Anatomy:Structural similarities link related species
Human hand Mole foot Bat wing Fly wing • The study of anatomy provides evidence of evolution. • Analogous structures have a similar function. • Analogous structures are not evidence of a common ancestor.
Structural patterns are clues to the history of a species. • Vestigial structures are remnants of organs or structures that had a function in an early ancestor. • Ostrich wings are examples of vestigial structures.
Comparative Biochemistry • Similar DNA sequences= • Similar Gene segments of the DNA • Code for similar traits • In closely related species