Defined: Collection of every known fossil Most fossils found in sedimentary rock Age determined by depth –Law of Superposition: new rock forms on top of older rock Evidence Conclusions: –1) Newer fossils are more complex –2) Common ancestors: similarities between ancient & modern life

Comparing old fossil to modern life shows change Ancient Kelp Modern Kelp

Radiometric Dating Helps determine age of fossils Isotopes: atoms of the same element with differing neutrons –Ex: 12 C and 14 C 12 C = 6 protons + 6 neutrons 14 C = 6 protons + 8 neutrons When organism dies: 14 C starts to decay Fossil age determined by comparing ratio of 12 C to 14 C Both are Carbon

(LUCA)prokaryotes Land prokaryotes Unicellulareukaryotes Multicellular plants Fish (first vertebrates) Land plants & fungi Land animals (amphibians) Amniotic egg (reptiles) Dinosaurs extinct Apes 24 Hour Earth Timeline Dinosaurs appear Outside links Link 1 Link 2 Scale: 1 minute = 3 million years

AKA: Transition Fossils –Archaeopteryx: shares both bird & reptile features –Basilosaurus: shares whale & land mammal features –Tiktaalik: shares fish & amphibian features Evidence Conclusion : Indicates common ancestry Reptile Evidence Teeth Bony tail Bird Evidence Wishbone Features Whale Evidence Long spine Found in dried up oceans Land Evidence Wolf-like teeth Hind legs Fish evidence Scales Fins Found in dried-up oceans Amphibian evidence Eyes on top of head Wrist bones

Defined: similar body structures with very different functions Different environments lead to adaptations –Ex: The forelimbs of animals Evidence Conclusion : Indicates common ancestry

Defined: Organs which have lost most or all their original function Vestigial Human Parts: –Gill slits = once used to breath oxygen in water –Yolk sac = once used to nourish developing embryo –Tailbone = once used for balance –Appendix = once used to digest plants –Wisdom teeth = once used to grind plant tissue Evidence Conclusion : Indicates common ancestry

Human Embryo w/ Vestigial Structures

Pythons have tiny femurs (leg bone)

DNA, RNA, proteins compared Genetic code same for most life More related species have more similar biochemistry Evidence Conclusion : Indicates common ancestry

Different species show similar development patterns Different body plans become noticeable later in development Evidence Conclusion : Indicates common ancestry

Antibiotics: drugs designed to kill bacteria –Obtained from fungi Antibiotic Resistance: Bacteria are adapting to the use of antibiotics –Misuse of antibiotics speeds up the process –Importance: Bacteria infections are becoming harder to treat –Example of natural selection Fungus Bacteria

Antibiotic Resistance GoodBad The antibiotics kill the bacteria, so the area around them are clear The antibiotics don’t kill the bacteria, that’s why there is no clear area around them.

Pesticides –Chemicals designed to kill pests (rodents, insects, etc…) –Pesticides sprayed on crops to kill pests Pesticide Resistance: pests are adapting to the use of pesticides –“Strong” pests survive to reproduce –Importance: Crops are being destroyed by pests

First life on earth were prokaryotes (bacteria) Changing environments lead to adaptation Much evidence indicates life has common ancestors