Describe the paleontological, embryological and molecular evidences for evolution.
How to lay out the answer. Follow the frame, then write it in your own words.
1 · Define evolution in one line. Evolution is the gradual change in organisms over generations, producing new forms from older ones.
2 · Explain fossil evidence.
Fossils are remains of hard parts preserved in sedimentary rock layers.
Lower layers are older; each layer has different life forms, some extinct like dinosaurs.
Age is found by radioactive dating.
3 · Explain embryological evidence. Haeckel: all vertebrate embryos show vestigial gill slits behind the head. Von Baer disapproved it: embryos never pass through the adult stages of other animals.
4 · Explain molecular evidence. Similar genes and proteins do the same job in diverse organisms; same genetic code; more alike in closely related organisms.
5 · Show a rock section if asked. [Diagram: layered sedimentary rock, oldest at bottom, fossils in each layer]
6 · Close in one line. So all three lines of evidence point to common ancestry and change over time.
Scoring tip: Name both Haeckel and von Baer, and say clearly that Haeckel's idea was disapproved. Examiners mark this down if left out.
