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