1. Evolution!

2. Vocab
Population- group of organisms of the SAME species that occupies certain area
Species- organisms that can INTERBREED and produce FERTILE offspring
Ex) Sauerman Woods Crown Point
-whitetail rabbits -deer
-sparrows -squirrels

3. Liger (lion and tiger)-infertile

4. Cama (camel and llama)-infertile

5. Tigon (tiger and lion)--infertile

6. Can we capture all the whitetail rabbits in Sauerman Woods?
Population Sampling- technique uses part of population to represent whole population
Capture 100 random rabbits
These rabbits are a representation of all the rabbits in the area.
We can study many things within this group…

7. Genetics of the Population…
Gene Pool- all of the genes of every individual in population sample
Frequency- how often something occurs
Population genetics involves studying the frequency with which certain alleles occur in a population’s gene pool.

8. In 50 years, will the allele frequencies be the same?
Hardy-Weinberg Equilibrium Principle –
“Under certain conditions, the frequencies of the
dominant and recessive alleles will remain the same
generation after generation.”

9. HARDY WEINBERG 5 CONDITIONS
To keep H-W equilibrium there must be:
No mutations
Large population
Population size remains same (no migration)
Random mating
No “survival of fittest” (evolution)
***These conditions are NEVER all met, so populations are always changing and NOT in
H-W equilibrium.

10. History of Evolutionary Thought
Before 1850, most people believed…
Earth formed by supernatural events and never changed.
Earth only a few thousand years old.
Each species was made to fit its environment.
Species never changed and did not go extinct.

11. History of Evolutionary Thought
Jean Baptiste Lamarck
Proposed that species DO evolve
***PROPOSED EVOLUTION OCCURRED BY INHERITANCE OF ACQUIRED CHARACTERISTICS

12. Lamarck Lamarck’s Hypothesis: 1. Desire causes change
Ex.) ancestors of birds had a desire to fly, so they did.
2. Use and Disuse
Ex.) If species used its arms to swim over and over, it would develop flippers. If not, flippers would disappear.
3. Traits acquired during life can be passed on
Ex.) Tiger Woods’ children will be great golfers.
WRONG!!!!

14. History of Evolutionary Thought
Alfred Wallace
English teacher who collected plants and insects.
Observed variations in organisms
Proposed that species DO evolve
 similar to Darwin’s
Sent idea to Darwin

15. Charles Darwin
At 22, sailed on the “HMS Beagle” to the Galapagos Islands.
Was going to school to be a minister-believed God created each species to match its habitat and they never changed.
Thought Earth was about 6,000 years old and didn’t change.

16. Charles Darwin cont.
During journey, he made observations and recorded them in a journal.
Darwin began to doubt that species remained “constant.”

17. Charles Darwin cont. In 1859, Darwin published The Origin of Species.
His book stirred up controversy.
Proposed **EVOLUTION OCCURRED BY NATURAL SELECTION

18. Major points of Darwin’s book:
Organisms have more offspring than can survive.
Certain individuals are more likely to survive than others (survival of the fittest.)
Species DO change over time.
Gradual changes may cause members of one species to eventually evolve into new species.
African apes are close genetic relatives of modern humans.
Darwin Video

19. What We Know Now Evolution is a Scientific Theory
Not a hypothesis, or an educated guess, or a “theory” in layman’s terms.
Unending amount of evidence to support it
Evolution is called “the unifying principle of Biology”
Isn't Evolution JUST a Theory?

20. Types of Evolution
Evolution - genetic change of a population of organisms over time- descent with modification
Microevolution:
Small genetic changes of a population
Shorter amount of time
Bengal tiger simulation was microevolution

21. Types of Evolution MACROevolution:
When new species are formed over long periods of time.
Due to tremendous amounts of accumulated genetic changes in a population
Speciation- formation of new species due to accumulated microevolution and mutations.

22. Speciation Geographic Isolation!
Geographical isolation- members of a population are separated geographically
Major step that leads to speciation.
Due to volcanoes, earthquakes, flooding, etc.
Can lead to divergence and then speciation.
Geographic
Isolation!

23. How does macroevolution work?
dibosirdsaur
GEOGRAPHIC ISOLATION
dibosirdsaur dibosirdsaur
10 million years of accumulated mutations
diosirdsaur ibosirdsaur
10 million years of accumulated mutations
diosirdsaur iboirdsaur
dinoirdsaur boirdsaur
dinordsaur boirdsur
dinodsaur boirdsu
dinodsaurs boirds
DINOSAURS BIRDS

24. Darwin and the Finches
When Darwin traveled to the Galapagos he took interest in the finches.
He noticed the finch species on the islands were different, but all resembled one from S. America.
Darwin thought some migrated and new species evolved. This is what he proposed:

25. Darwin’s Finches Finches migrated from South America to the islands
Populations on different islands adapted to different environments and food sources they found.

27. Darwin’s Finches
Different mutations accumulated in the different populations on the different islands and they became more and more different from each other.
Divergence- the accumulation of differences between species or populations.

28. Darwin’s Finches
Over time the populations on the islands became so different they no longer mated->speciation
Several new finch species evolved from a common ancestor from S. America
This is an example of macroevolution

29. Recent finch
research

30. Darwin’s Natural Selection is the Driving Force Behind Evolution
Natural selection- organisms best suited to their environment survive and reproduce.
Darwin’s proposed mechanism of evolution
Survival depends on the particular environmental conditions a species finds itself in—nature!
If the environment changes, so do the populations that live there.
Adaptation- using inherited genetic characteristics to increase chance of survival in new environment.
Natural Selection and Salamanders

31. Whose idea for
evolution is this?

32. Natural Selection
Three conditions necessary for natural selection to occur:
Genetic variation: Individuals within a population must be genetically different. This is due to mutation.
****Random mutations are the raw material for evolution to occur!!!!!!!
Overproduction of offspring: More organisms are born than can survive.
Differential reproduction: Certain traits enable individuals to survive and have more offspring than others.—SURVIVAL OF THE FITTEST

33. Natural Selection Result of Natural Selection:
Genes that help a species survive stay in the gene pool.
“Unfavorable” genes gradually decrease.
This causes changes in the genetics of populations EVOLUTION!!!!!
Over a long time, the new populations no longer can mate with the original they started as. New species have formed.

34. Natural Selection Example
The industrial revolution
In England in the early 1800’s industry boomed
Factories, trains, smoke and smog
Peppered moths were dark or light colored, and the dark ones that were once rare became more common.
Hypothesis?

35. The Peppered Moth Kettlewell tested this hypothesis
Released equal numbers of moths in polluted AND clean forests.
In industrialized areas, dark gray moth was better camouflaged.
They survived, had more offspring
The population *as a whole* evolved to be better suited to the environment more gray and camouflagedADAPTATION!
This is an example of microevolution

36. The Peppered Moth
Peppered Moth Simulation

37. geographical isolation
EVOLUTION
by natural selection
Microevolution
MACROevolution
Changes
in gene frequencies
in a population
Accumulated
microevolution and
mutations to form
whole new species
Examples:
Peppered moth
and Bengal tiger
Shorter times
Examples:
Darwin’s finches and
geographical isolation
Longer times

38. Artificial Selection
Artificial selection- human intervention in animal or plant reproduction to ensure that certain desirable traits are passed on.
Instead of NATURE selecting which traits are favorable, HUMANS selectively breed those animals with favorable traits.
Ex. dogs or racehorses