Slide 1

feathers claws thin ribs teeth long tail wing-like forelimbs Reptile-like features Bird-like features Replica of Archaeopteryx fossil; half bird half reptile 16

Slide 2

Vertebrates Fish, amphibia, reptiles, birds and mammals all have vertebral columns, skulls, brains, circulatory systems and many other features in common This suggests that they all arose from a common ancestral form rather than arising independently. The same reasoning can be applied to other groups of organisms such as insects which have most of their anatomical features in common Although these features are superficially different there is a basic pattern underlying them all 18

Slide 3

Vertebrate limbs The basic pattern of the vertebrate limb is represented by the human arm skeleton shown below ball and socket joint hinge joint single bone two bones group of small bones five jointed digits 17

Slide 4

The forelimbs of the following vertebrates show the basic pattern of limb bones with modifications which are adapted to their methods of locomotion. LizardBird DolphinBat The basic pattern suggests they have evolved from a common ancestor 19

Slide 5

Mammals Flatworms Annelids InsectsCoelenterates Fish Birds Reptiles Crustacea Amphibia Single celled organisms MonocotsHerbsShrubsTrees Dicots Flowering plants Conifers Mosses LiverwortsAlgae Ferns Fungi Multicellular plants Multicellular animals Mollusc 22