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