September 18, 2012
Introduction of Anthropology: Evolution and Genetics
- evolution is decent with modification
- history and evolution
- case studies
Concepts: Evolution and human origins
what is evolution? How's does it work?
1. Adapt to environment
2. Natural selection
3. Sexual selection
4. Variation already exists
5. Survival of the fittest
What is a species?
A group of creates which breed together and produce viable and fertile offspring.
- may be quite similar in appearance (deer) or quite variable (dog)
- may all live in one art of the world or in many parts of the world
- share behavioral traits relating to social groups, foods preference, reproductive strategies, etc.
- distinguished between members of own species and others
Pre- Enlightening Period (1600-1700s)
- According to Genesis - Adam and Eve created story
- everything was made in 6 days
History of Origins
Origin of the Earth and therefore humans based on his interpretation of the bible.
- Archbishop Ussher (1640AD)
First person to tell us about the origins of the earth
He sat down with genesis and counted out the number of generations in the book of genesis to figure out
how old the world was. He figured out it was 6,000 years at the time. He thought the exact day was
- George Cuvier
- if only 6000 years old, then global and violent catastrophes to explain canyons, mountains....?
- Reverend Burnet (1681AD)
Noticed the things like erosions where happening in slow processes not fast catastrophes
slow erosion? Water, wind and ice
********* Uniformitarianism *********
Uniformitarianism: the assumption that the same natural laws and processes that operate in the universe
now, have always operated in the universe in the past and apply everywhere in the universe.
- Buffon (1749AD) "to learn about the earth study the earth" process are known, natural and observable
that we should be able to record the processes we see today to explain the past. He retracted this
statement for fear of his life.
- Hutton (1788AD) slow working uniform and natural process = hundreds of thousands of years.came to
the conclusion that the earth was 100,000 years old September 18, 2012
- Lyell (1873Ad) 100,000 years "The present is the key to the past"
- Reverend Chalmer - Ussher was wrong, not the bible. That he didn't count back the number of
generations correctly and the earth is 100,000 years old
At the same time ......
Carolus Linnesius (1748)
Famous for naming most for naming most of the species of the plant. Plants and animal, came up with
the binomial system, he did this by using functional anatomy.
Linnesius tried to look at the relationship between different species based on how similar or different their
appearance was. What he inadvertently done were name humans as one of these animal species. He
was the first to say that we are a part of the same system.
- comparative biology
- categorizing the worlds plants and animals
- 7 basic layers or taxon levels
- Kingdom, Phylum, Class, Order, Family, Genus, Species
- Binomial system
- Homo sapiens ( wise man)
Adding to the fire
- identified new people's not mentioned in the bible
- stones tools
Life on earth had changed
- conclusion of the enlightenment period
- extinct animals
- strata and stratigraphy
- 1800's the question changed to "How did the earth/ species change"
Lamarck - first mechanism
1. Species adaptation to the environment = TRUE
Examples: during the drought the animals who can reach the leaves are more likely to survive so the trait
for the stretched neck is past on.
2. Species progression towards perfection = FALSE
Examples: worms would eventually evolve into humans and humans would evolve into angles.
3. Species inheritance of acquired characteristics = FALSE
Examples: whatever characteristics your parents acquired would be pasted down to you.
Darwin and Wallace
Mechanism of natural selection
- natural selection
Variation already exists between individuals of the same species allows for adaptation to changes in the
environment. Evolution happens to populations not individuals. It's the frequency of traits in the population
- Survival of the fittest and sexual selection
Those individuals that are by the chance best adapted to an environment will have higher reproductive
- increases the frequency of that within the species/population
- variation is random and there is no direction
- Changes occurs as an adaptation to a changing local environment.
- Change works on the variation of traits already present in a population September 18, 2012
- no direction
1. Favorable variation promotes survival of individual in whom they appear
- traits are inherited by their offspring, whose chances of survival also better.
- Favorable variation eventually spread through the population
2. Unfavorable variations don't promote survival
- may cause the individuals to die at an early age
- may reduce the fertility of bearers, who have few off springs
- either way, unfavorable baristas tend to be removed from the population
3. For any species, natural forces act to favor the expansion for some traits and to favor the removal of
other traits from future generation.
What is evolution and natural selection working on?
- genetic flow
- genetic drift
Gregor Mendel: Austria 1822 - 1884
- breeding experiments with pea plants.
- traits in offspring are not passed solely by either parent
- traits are passed in small, independent packages from both parents
- we call these packages "genes"
Mendel's breeding program
- cross-bred green peas with green peas
- offspring of any generation always had green peas
- cross-breed yellow peas with green peas
- all offspring plants (f1 generation) bore green peas
- cross-bred green offspring (f1 generation) had green peas and some had yellow peas
- some of their offspring plants (f2 generation) had green peas and some had yellow peas
- ration of green to yellow plants in f2 generation was always 3:1
- what would the pun net square look like if we crossed:
- green YY and green Yy
- each observed trait derives from a package of information (gene) acquired by the individual at
- for each trait, an individual possesses two genes: one from each parent.
- Two matching genes Homozygous state: For a given trait, individual receives the same gene form
from parents. Green and Green
- heterozygous state: Individual receives two different gene forms