The document discusses pentadactyl limbs, which have five digits, in different organisms like crocodiles, penguins, echidnas, and frogs. It also discusses speciation and evidence from geographical variation, specifically focusing on the finches of Daphne Major island. The document appears to be from an IB Biology textbook covering evolution and natural selection, and discusses limb structure and function in different organisms as well as speciation patterns seen in island finches.

1. Evolution & Natural Selection (5.1-5.2)
IB Diploma Biology

8. Pentadactyl Limbs
Organism (type) Function of pentadactly limb
Crocodile (reptile) Walk or crawl on land / Hind legs used for swimming
Penguin (bird) Hind limbs for walking / forelimbs for swimming
Echidna (mammal) All four limbs used for walking / Forelimbs for digging
Frog (amphibian) All four limbs used for walking / Hindlimbs for jumping

9. Speciation

10. Evidence from Patterns of Geographical Variation

30. The Finches of Daphne Major

40. Bibliography / Acknowledgments
Jason de Nys
Chris Paine