Evolutionary Timeline Summary 10 20 bya Galaxy forms
Evolutionary Timeline Summary • 10 -20 bya: Galaxy forms • 5 bya: Earth forms • 4 bya: Life forms from non-life • 3 bya: Cyanobacteria evolve photosynthesis • 500 mya: Explosion of Life - Massive Extinction • 150 mya: Dinosaurs evolve • 66 mya: Dinosaurs become extinct • 5 mya: Humans begin to evolve • 50 tya: Neanderthals/Cro-Magnon • 10 tya: Homo sapians
Dinosaur Extinction? • Crater found • Dated to dinosaur extinctions • 66 million years ago • Iridium • Would we have evolved if this didn’t happen?
Humble Beginnings?
Evolution of Nervous Systems • radial nerve • nerve net • segmental nerve • ganglion • nervous system
Vertebrate Brain Evolution • midbrain emphasis decreases • forebrain emphasis increases • cerebellar emphasis increases
The Human Lineage
Human Evolution and Brain Size Increases
Varied Cortical Commitment Association Areas Increase with Evolution
Varied Cortical Surface Area
Genetics and Evolution Modern Day Chimpanzee Modern Day Human
Evolution of Language Chimpanzee Human High in throat Low in throat • A random mutation causes the larynx to drop in human ancestor • This increases the complexity of sounds that the species could make • Couple this with a more complex brain and we have the advent of language • And the evolution of the species based on cognition and language
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