Lesson 8

Human Abilities & Success  Perform complex reasoning  Ability to learn  Use of sophisticated tools  Use of complex language

Human Abilities Required the Evolution of physical characteristics:  Large Brain relative to body size  Hands that are capable of fine manipulation and coordination  Bipedalism – walking upright allowing our hands to be free for tool use

Human Phylogeny

 New World & Old World  Continental drift that separated South America (New World) from the land mass that would form Africa and Eurasia (Old World)

 Humans and Chimpanzees share approximately 98.8% of their DNA  Humans and chimpanzees differ from gorillas by about 1.6%  The most recent common ancestor that we share with chimpanzees lived in Africa more than 6 million years ago

Human “Races”  From a biological perspective, human ‘races’ do NOT exist. There is NO significant genetic difference between people around the world  Traits that we associate with races (skin colour) are visually obvious, but genetically minimal

Hominid Fossil Record

 Mary Leaky in 1976 discovered the Laetoli footprints in Tanzania

Out of Africa  All early hominids evolved and lived in Africa  Homo erectus was the first species to spread beyond Africa about 1.9 million years ago  Ancestors of Neanderthals spread beyond African about to years ago  Soon after the earliest modern human evolved, they too spread out of Africa

DNA & Fossils  DNA from Neanderthal bones have been sequenced and we have its genome  Genetic remnant of Neanderthal genome found in humans of European and Asian decent. There is no function of this DNA, but it suggests interbreeding

Cultural Evolution  Even if humans and chimps are 98% genetically related, our cultural differences are immense  How has our biological evolution influenced our cultural evolution?

Evolution Today & Darwinian Medicine  Darwinian Medicine:  Application of modern evolutionary theory to understand health and disease  Ex: Taste for fats and sugars  Ex: Spiking a fever to help fight an infection  Ex: Coughing to expel disease-causing agents from lungs

Modern Theory of Evolution  Read section 7.6

Epigenetics  Recall Use and Disuse:

Epigenetics:  Epigenetics is the study of heritable changes in gene activity which are not caused by changes in the DNA sequence.heritablegeneDNA  Changes can occur response to environmental influences   ARTICLE: grandmas-experiences-leave-epigenetic-mark-on- your-genes

Homework:  Read 7.6 Modern Theory of Evolution  Do some more research on epigentics