1. Charles Darwin Born in England At age 22 sailed around the world
Collected data on the Natural World
Boat = H.M.S Beagle

2. Darwin’s Observations
Diversity
Organisms are well adapted for their environment
Distribution – why no rabbits in Australia or kangaroos in England?
Fossils
Why are some organisms extinct?
Why are some fossils similar to existing organisms?

3. The Galapagos Islands
Tortoises – the shape of their shells are different from one island to the next. Each adapted to that islands environment.
Mix of food (vegetation) on the ground and on small bushes
Lots of food (vegetation) on trees and bushes
Lots of food (vegetation) on the ground

4. The Origin of Species Published 25 years after his voyage
Basis for the Theory of Evolution by Natural Selection

5. Hutton and Lyell
Geological events are always changing the earth (volcanoes, rivers, etc…)
The earth is millions of years old

6. Lamarck’s WRONG Hypothesis
Jean Baptise Lamarck (1809)
First to develop a scientific hypothesis about evolution
First to recognize organisms adapted to their environments
Wrong ideas – If an organism acquired or lost certain traits, these traits would be passed on.

7. Thomas Malthus
Thomas Malthus (1798) – noted the human population is growing
At some point humans would run out of food and/or living space
Darwin realized that Malthus’s ideas applied to all living things.
What factors determine who lives and dies when food or space run out?

8. Evolution
Evolution- the process of cumulative change in the heritable characteristics of a population.
Theory of Evolution - By the process of natural selection populations will change and may give rise to new species

9. Artificial Selection – humans select reproduction
Parents pass on their traits (determined by their DNA) to their offspring.
Variation: Individuals of a species are different from each other.
Ex: Dogs and Wolves
Artificial Selection – humans select reproduction
a.k.a. – selective breeding

11. Natural Selection
Darwin compared artificial selection to natural selection
Populations produce more offspring than can survive (K)
Individual must struggle and compete for survival
Each individual in a population is different (variation)
differences may help that individual survive and produce a greater percentage of offspring (advantage)
Hereditable traits that individual has gets passed on to its offspring
As each generation of offspring survives better (and has greater number of offspring) the traits that gives those individuals an advantage becomes more numerous in the population.

12. Evolution by Natural Selection
Natural selection leads to organisms that are well suited for a particular environment.

13. Descent with Modification
As time goes by, organisms become well adapted to their environment
Become different then their ancestors
Eventually, with enough change, can become a different species.
Common Descent
At some point all organisms have the same ancestor
Similar to a family tree

14. Proof of Evolution: Homologous body structures
Structures that are similar due to evolutionary origin
Ex: Forearms in different animals all have the same bones

15. Proof of Evolution: Vestigial Organs Ex: Leg structures in a whale
Body structures that serve no purpose
Ex: Leg structures in a whale
Ex: Human tail bone

17. Proof of Evolution: Embryonic Similarities
Embryos of different species are very similar

18. Snake Chicken Possum Cat Bat Human

19. Proof of Evolution: Molecular Evidence
All life uses similar arrangement of atoms and molecules
Ex: DNA is used by most organisms
Similarities in DNA or Amino acids can show how closely related species are to each other.
Genetics explain how favorable traits are passed on

20. Proof of Evolution: Fossil Evidence
By comparing fossils of different ages Evolution is evident

21. Proof of Evolution: Geographical Distribution of Living Organisms
the distribution of placental, marsupial and monotreme animals
Isolation:
Australia has been isolated from other continents for over 100 million years, without a land bridge for dispersal of mammals from other continents
Independent evolution:
Marsupials and monotremes entered Australia before its separation from the other continents, and have evolved independently ever since, without competition from placental mammals, adaptively radiating into a wide variety of species, 200 of which survive today.

22. Geographical Distribution of Living Organisms (Cont.)

23. Proof of Evolution: Selective breeding Artificial selection
Humans controlling the breeding of animals or plants having desirable characters… creating an evolution of the species

24. Advanced Evolution Concepts

25. Endosymbiotic Theory
Both mitochondria and chloroplasts were once independent prokaryotic cells that were engulfed by a larger heterotrophic cell
Instead of being digested, however, the cells were kept alive and continued to function as usual
Eventually this evolved into the eukaryotic cell

27. Endosymbiotic Evidence
Mitochondria and chloroplasts grow and divide like cells
They each have a loop of naked DNA like prokaryotes
They synthesize their own individual proteins using 70s ribosomes like a prokaryote
They have double membranes – something you would only expect a self sufficient cell membrane to have, and not an organelle

28. Eukaryotic Development
Some evidence that cilia and flagella could possibly have endosymbiotic origins, but not clear
Eukaryotic chromosomes, meiosis and sexual reproduction had to evolve in eukaryotic cells as well
Once this occurred, evolution could occur at a much more rapid pace than before
Described as “an explosion of life” on Earth once sex finally evolved

29. What is a species?
A group of actually or potentially interbreeding populations with a common gene pool which are reproductively isolated from other such groups
In other words – you gotta be able to make babies together or you’re kicked out of the gene pool

30. Variation Vocabulary! Gene Pool – all the genes in a population
All genes for different traits
All variation of all traits
Example – all the genes that could possibly be found in any human
Relative Frequency – how common an allele is
Percentage of the population with that allele
Evolution is a change in relative frequency!

31. Sources of Genetic Variation
Mutations – are changes in DNA
May have no effect
May cause cancer
May Causes change in proteins.
Change in phenotype
Could effect organisms ability to compete
Point Mutation – change in one area of DNA
Substitution
Insertion
Deletion
Frameshift mutations

32. Sources of Genetic Variation
Gene Shuffling
Law of Independent Assortment
All of your mom’s DNA does not end up in one gamete and all of your dad’s in a different gamete.
Each of your gametes will be a mixture of your mom’s and dad’s gametes
A fertilized egg will by a mixture of all 4 grandparent's DNA
Crossing Over
Occurs in Meiosis.

33. Speciation Speciation is the evolution of a new species
Literally means “Splitting of lineages”
Happens for several different reasons:
Genetic Drift is a major cause
Different mutations in the same population
Leads to the creation of different niches
Isolation

34. Isolation
Reproductive Isolation – when at least two groups are unable to reproduce with the other group.
Leads to new species
Three reasons for Isolation
Behavioral Isolation
ex: mating calls
Geographic Isolation
ex: islands, mountain or river barriers
Temporal Isolation
ex: Time, mating time…

35. Allopatric Speciation
Formation of a new species
Can be allopatric or sympatric
Allopatric speciation – when members of a species migrate to a new area forming a population that is geographically isolated
Example: Galapagos Islands tortoises, lizards or finches

36. Sympatric Speciation
Occurs when two varieties of a species live in the same geographic area but do not interbreed. Two forms:
Barriers occur that prevent reproduction from occurring altogether.
Behavioral isolation
Temporal isolation
Barriers occur based on hybrid infertility, often due to polyploidy

37. Evolutionary Trends
Divergent evolution – each species evolves in different ways by becoming adapted to different ecological roles
Adaptive radiation – if species in a group diverge rapidly, one species forming many

38. Convergent Evolution
Organisms who find similar solutions to the same problem but are not closely related to each other

39. Coevolution When two organism’s evolutions are connected to each other
Example: Bees and plants, cheetahs and impalas

40. Rates of Evolution
Gradualism – the idea that evolution occurs very slowly over time
Punctuated equilibrium – evolution occurs at a slow pace but is occasionally interrupted by some sort of event that causes brief periods of major changes
Supported more by the fossil record

41. Polymorphism
When a population has two alleles of the same gene in the gene pool it is said to be polymorphic
If one allele is gradually replacing the other, the population shows transient polymorphism
Peppered moths of England
Sometime both alleles can persist indefinitely in the gene pool. This is known as balanced polymorphism
Sickle cell anemia
HbAHbA = normal genotype, susceptible to malaria
HbSHbS = resistant to malaria, has sickle cell anemia
HbAHbS = best adapted in area, resistant to malaria and free of sickle cell anemia

42. Basics of Taxonomy

43. Binomial Nomenclature
Created by Carolus Linnaeus in 1758
Binomial Nomenclature uses the Latin genus and species name
Binomial – literally means “two names”
Nomenclature – means a system of naming

44. Classification (two) (names) Binomial Nomenclature
Taxonomy – The science of naming and classifying organisms
All of the earth’s organisms, from the tiniest bacteria to the largest animals, can be named using the two word system
Binomial Nomenclature
(two) (names)

45. Scientific Name: Examples: Homo sapiens Quercus rubra or or
1st word = genus
always Capitalized
2nd word = species always lowercase
Both words underlined or italicized
Examples:
Homo sapiens Quercus rubra
or or
Homo sapiens Quercus rubra
(humans) (red oak tree)

46. How are organisms classified?
Kingdom (6)
Phylum
Class
Order
Family
Genus
Species
The least specific
The most specific

47. Figure 18-5 Classification of Ursus arctos
Giant panda
Abert squirrel
Coral snake
Grizzly bear
Black bear
Red fox
Sea star
KINGDOM Animalia
PHYLUM Chordata
CLASS Mammalia
ORDER Carnivora
FAMILY Ursidae
GENUS Ursus
SPECIES Ursus arctos

48. Dichotomous Key
How did Linnaeus sort through all of those animals at first?
Dichotomous Key – a tool used by scientists to research new organisms and to figure out scientific names
Asks a series of yes/no questions to sort through characteristics