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 fossils 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

Timelines like this are accurate, but the scale of time it too massive for us to visualize…So let’s try a different scale of time

24 Hour Life Timeline Scale: 1 minute = 3 million years This timeline shrinks Earth’s existence to a 24 hour day. We all can visualize 24 hours.

Fossils show that the oldest life is ~3.5 byo…bacteria

Bacteria (3.5 billion) 24 Hour Life Timeline Scale: 1 minute = 3 million years

Fossils show the first vertebrates (fish) lived ~510mya.

Fish (510 million) 24 Hour Life Timeline Scale: 1 minute = 3 million years Bacteria (3.5 billion)

Fossils show the first land animals (amphibians) lived ~340mya

Amphibians (340 million) 24 Hour Life Timeline Scale: 1 minute = 3 million years Bacteria (3.5 billion) Fish (510 million)

Fossils show that reptiles first lived ~310mya

Reptiles (310 million) 24 Hour Life Timeline Scale: 1 minute = 3 million years Bacteria (3.5 billion) Fish (510 million) Amphibians (340 million)

Fossils show that mammals and dinosaurs first lived ~250mya

24 Hour Life Timeline Scale: 1 minute = 3 million years Dinosaurs & mammals (250m) Bacteria (3.5 billion) Fish (510 million) Amphibians (340 million) Reptiles (310 million)

Fossils show that flowering plants and birds first lived ~175mya

24 Hour Life Timeline Scale: 1 minute = 3 million years Bacteria (3.5 billion) Amphibians (340 million) Fish (510 million) Reptiles (310 million) Dinosaurs & mammals (250m) Flowers and birds (175 m)

Fossils show that humans first lived ~200,000 years ago

Humans (200,000) 24 Hour Life Timeline Scale: 1 minute = 3 million years Bacteria (3.5 billion) Amphibians (340 million) Fish (510 million) Reptiles (310 million) Dinosaurs & mammals (250m) Flowers and birds (175 m) 1 second = 50,000 years So if humans have been around for 200,000 years, how many seconds before midnight did we evolve?

Humans (200,000) Other Notable Events Scale: 1 minute = 3 million years Bacteria (3.5 billion) Amphibians (340 million) Fish (510 million) Reptiles (310 million) Dinosaurs & mammals (250m) Flowers and birds (175 m) Unicellulareukaryotes First plants (aquatic) Dinosaurs extinct Obvious conclusion: Life began very simple and gradually became more complex

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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 Feathers 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: 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)

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

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

Constant creation of chemicals for human use is eliminating the “unfit” organisms –Ex: Antibiotics eliminating unfit bacteria –Ex: Pesticides eliminating unfit pests –Ex: Antivirals… –Ex: Fungicides… Allows resistant to survive and reproduce

Antibiotic Resistance Which antibiotics would successfully treat this infection? penicillin ampicillin Amoxycillin tetracyclin vancomycin

How does antibiotic and pesticide resistance show natural selection? How do the following lines of evidence show change over time? –Fossils –Homologous structures –Vestigial structures –Resistant organisms –Embryo development –Biochemical evidence Fossil age can be determined two ways. What are they?