IV. Evidence for Evolution Evolution is supported by scientific evidence from many disciplines including geography, geology, and biochemistry B. Direct Observations 1. Insect populations rapidly become resistant to DDT and other pesticides

2. Drug-resistant bacteria, viruses, and cancers

3. Development of melanistic insects in polluted environments a. In an unpolluted environment, the trees are covered by a pale-colored lichen, which provides camouflage for the light moth. b. In a polluted environment, Sulphur dioxide kills the lichen while soot blackens the bark, providing camouflage for the dark moth. Industrial revolution – 95-100% of moths melanistic Today, 0-30% of moths melanistic thanks to clean air act

4. Guppies moved to low- predation environments produce fewer and larger offspring in less than 30 generations John Endler

C. Comparative anatomy – comparing morphology (body shapes & structures) for similarity resulting from common ancestry 1. Homologous structures - anatomical structures that have been adapted to different environments/functions, but have the same underlying structure (More structures two species have in common more closely related they are) Ex. Pentadactyl limbs of higher vertebrates

2. Embryonic homologies – early development shows similarities that are not necessarily seen in adult forms a. Ex. All vertebrate embryos have a post- anal tail and pharyngeal pouches

3. Vestigial Structures – remnants of structures that served a purpose in an ancestor, but have limited/no function now a. Hip bones in pythons and whales

D. Molecular Homologies 1 D. Molecular Homologies 1. Similarities in DNA, RNA, or protein sequences 2. ALWAYS the most important evidence for determining evolutionary relationships *BLAST website

E. The Fossil Record 1. Fossils are remains or traces of organisms from the past (bones, footprints, etc.) found in sedimentary rock Extant vs. extinct

2. Show change in organisms over time 3 2. Show change in organisms over time 3. Transitional fossils have been found that link ancient organisms to modern species

F. Biogeography 1. Geographic distribution of species 2 F. Biogeography 1. Geographic distribution of species 2. Species that live nearer each other tend to be more closely related.

3. Endemic species – species found only in a certain geographic location Marine iguanas are endemic to the Galapagos islands

4. Continental drift – break-up of Pangaea Ex. Australia broke away earliest which explains why it has so many endemic species