Evolution Over Time
By: Lena Martens
- Earliest Fossil Bacteria
- 2,750 Million Years Ago
- Precambrian Era
- Origin of O2 by Photosynthesis
- 2,500 Million Years Ago
- Precambrian Era
- First Eukaryotes
- 1,500 Million Years Ago
- Precambrian Era
- Early Eukaryotes
- 1,500 Million Years Ago
- Precambrian Era
- Diverse Protists
- 1,000 Million Years Ago
- Precambrian Era
- Earliest Multicellular Organism
- 700 Million Years Ago
- Precambrian Era
- Origin of Major Animal Phyla
- 520 Million Years Ago
- Cambrian Period
- Origin of All Major Animal Phyla
- 510 Million Years Ago
- Cambrian Period
- Animal Diversity Abounds ; First Jawless Fish
- 500 Million Years Ago
- Ordovician Period
- First Mass Extinction
- 440 Million Years Ago
- Ordovician Period
- Plants and Arthropods Invade Land ; Jawed Fish First Appear
- 440 Million Years Ago
- Ordovician Period
- Bony Fish Became Abundant
- 400 Million Years Ago
- Devonian Period
- Early Amphibians
- 370 Million Years Ago
- Devonian Period
- Second Mass Extinction
- 360 Million Years Ago
- Devonian Period
- Early Reptiles
- 350 Million Years Ago
- Carboniferous Period
- Third Mass Extinction
- 250 Million Years Ago
- Carboniferous Period
- The First Dinosaurs and Mammals
- 240 Million Years Ago
- Triassic Period
- Fourth Mass Extinction
- 200 Million Years Ago
- Triassic Period
- Dinosaurs
- 180 Million Years Ago
- Jurassic Period
- Appearance of Flowering Plants
- 120 Million Years Ago
- Cretaceous Period
- Fifth Mass Extinction
- 65 Million Years Ago
- Cretaceous Period
- Birds and Mammals Spread
- 60 Million Years Ago
- Tertiary Period
- Major Mammal Groups Evolve
- 40 Million Years Ago
- Tertiary Period
- Mammals Abundant on Land
- 20 Million Years Ago
- Tertiary Period
- Appearance of Australopithecus
- 5 Million Years Ago
- Tertiary Period
- First Homo Sapiens
- .5 Million Years Ago
- Quaternary Period