lesson 8. human abilities & success perform complex reasoning ability to learn use of...
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HUMAN EVOLUTION & MODERN EVOLUTION THEORY
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 500 000 to 300 000 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 culturalevolution?
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.
Changes can occur response to environmental
influences
http://www.youtube.com/watch?v=kp1bZEUgqVI ARTICLE:
http://discovermagazine.com/2013/may/13-grandmas-experiences-leave-epigenetic-mark-on-your-genes
Homework:
Read 7.6 Modern Theory of Evolution Do some more research on
epigentics