1. Unit 4 Evolution CH 10: Principles of Evolution
Ch 11: Evolution of Populations
Ch 12: The History of Life

2. Ch 10 Principles of Evolution 10.1 Early ideas about evolution
Scientists:
Carolus Linneaus: Swedish botanist, developed classification system (binomial nomenclature) for species
Georges Louis Leclerc de Buffon: French naturalist, suggested species shared ancestors, he and Charles Lyell suggested earth was much oder then 6000yrs
Erasmus Darwin: Charles’ grandfather, English doctor/ poet, proposed living things from common ancestor

3. 10.1 cont’d Leading up to Darwin’s theory
Jean-Baptiste Lamarck: French naturalist, proposed all organisms evolved towards perfection/ complexity b/c of change in enviro.
Leading up to Darwin’s theory
Georges Cuvier: French zoologist, fossils different in layers and catastrophism
James Hutton: Scottish geologist, proposed gradualism
Charles Lyell: English geologist, agreed and theory of uniformitarism

4. 10.2 Darwin’s observations
Island species differences
Variation was interspecific and intraspecific based on islands he visited
Galapagos Islands: tortoises (necks/ legs), finches (size beak)

5. Darwin’s observations cont’d
Fossil/ geologic evidence
Giant armadillo fossils; suggested ancestor and earth older 6000yrs
Marine fossils in mountains; volcanoes/ other activity changed land over time (gradualism)
Darwin and His Work

6. 10.3 Theory of Natural Selection
Artificial selections- people make genetic diversity of plants/animals
Natural selection
Darwin- heredity; Malthus- struggle for survival/ competition
neck feathers
crop
tail feathers

7. 4 principles of Natural Selection:
Variation: inherited/ mutations
Overproduction: many offspring= survival or compete
Adaptation: better suited for environment
Descent with modification: better trait passed on
“fitness”: ability to survive in environment/ adapt
wrist bone
five digits

8. 10.3 cont’d Natural selection changes phenotypes not genotypes
Why evolve?
Changing environments: ex food/ finches
Not really ‘passed on’ over many generations, can be response to need in environment
Natural Selection

9. Quick Data Lab Pg 290

10. 10.4 Evidence of Evolution Evidence/ support
Fossils: age/ location/ environment when organism was alive; layers had oldest at bottom
Geography: Galapagos similar plants/ animals as S. America; distance from mainland, biogeography

11. Embryology: crab/ barnacles look alike as larva; embryos in verts
Embryology: crab/ barnacles look alike as larva; embryos in verts. Look similar too
Anatomy: homologous structures (forelimbs)- look same but have different functions; analogous structures (wings)- do the same function, but look very different; vestigial structures (ostrich/snake)- organs or structures had function for earlier ancestors
Human hand
Bat wing
Mole foot
Human hand
Bat wing
Mole foot
Fly wing

12. 10.5 Evolutionary Biology Today
Paleontology- fossils/ extinct organisms; NEW and lacked transitional fossils

13. Fossil/ anatomical evidence
DNA sequence analysis: nucleotides show how closely related
Pseudogenes: no longer function but still in DNA (like vestigial organs)
Homeobox genes: control development of specific structures- links us back to common ancestor
Protein comparisons: molecular fingerprinting to show common cells and make ancestor connections

14. Videos of Evolutionary Biology
Evolution is in all biology fields!
Natural Selection
Evolutionary Bio 1
Evolutionary Bio 2

15. End of CH 10 Review Pick 2 of the following to complete
Title the page “Ch 10 review” and keep it in your classwork section.
Student Premium: Animated Biology clips
Student Premium: Virtual Investigation
Student Premium: Interactive Review Games

16. 11.1 Genetic Variation within Popln
Genetic variation leads to phenotypic variation.
Phenotypic variation is necessary for natural selection.
Genetic variation is stored in a population’s gene pool.
made up of all alleles in a population
allele combinations form when organisms have offspring

17. Genetic variation comes from several sources.
Mutation is a random change in the DNA of a gene.
can form new allele
can be passed on to offspring if in reproductive cells
Recombination forms new combinations of alleles.
usually occurs during meiosis
parents’ alleles arranged in new ways in gametes

18. 11.2 Natural Selection in Popln
A normal distribution graphs as a bell-shaped curve.
highest frequency near mean value
frequencies decrease toward each extreme value
Traits not undergoing natural selection have a normal distribution.

19. Natural Selection changes poplns
Microevolution is evolution within a population. (observable change in the allele frequencies)
Directional selection favors phenotypes at one extreme.
Stabilizing selection favors the intermediate phenotype.
Disruptive selection favors both extreme phenotypes.

20. Directional selection
Stabilizing selection
Disruptive selection

21. 11.3 Other Mechanisms of Evolution
Genetic drift causes a loss of genetic diversity.
It is most common in small populations.
A population bottleneck can lead to genetic drift.
It occurs when a few individuals start a new population.
The founder effect is genetic drift that occurs after start of new population.

22. Genetic drift has negative effects on a population.
less likely to have some individuals that can adapt
harmful alleles can become more common due to chance
There are two types of sexual selection.
intrasexual selection: competition among males
intersexual selection: males display certain traits to females

23. 11.4 Hardy-Weinberg Equilibrium
very large population: no genetic drift
no emigration or immigration: no gene flow
no mutations: no new alleles added to gene pool
random mating: no sexual selection
no natural selection: all traits aid equally in survival
p2 + 2pq + q2 = 1
"The Hardy-Weinberg equation is based on Mendelian genetics. It is derived from a simple Punnett square in which p is the frequency of the dominant allele and q is the frequency of the recessive allele."

25. 11.5 Speciation through isolation
Populations become isolated when there is no gene flow.
Isolated populations adapt to their own environments.
Genetic differences can add up over generations.
Reproductive isolation can occur between isolated populations.
Behavioral barriers can cause isolation.
called behavioral isolation
includes differences in courtship or mating behaviors

26. Geographic barriers can cause isolation.
Speciation is the rise of two or more species from one existing species.
Geographic barriers can cause isolation.
called geographic isolation
physical barriers divide population
Temporal barriers can cause isolation.
called temporal isolation
timing of reproductive periods prevents mating

27. 11.6 Patterns of evolution Natural selection can have direction.
Convergent evolution: evolution similar traits in unrelated species.
Divergent evolution: evolution toward different traits in closely related species.

28. Mass extinctions are rare but much more intense.
destroy many species at global level
thought to be caused by catastrophic events
at least five mass extinctions in last 600 million years

29. Many species evolve from one species during adaptive radiation.
ancestral species diversifies into many descendent species
descendent species usually adapted to wide range of environments

30. Ch 12 The History of Life 12.1 The Fossil Record
How Fossils Form:
Permineralization: minerals carried by water are deposited around a hard structure.
Natural cast forms: flowing water removes all of the original tissue, leaving an impression.
Amber-preserved fossils: organisms that become trapped in tree resin that hardens after the tree is buried.
Preserved remains form when an entire organism becomes encased in material such as ice.
Only a tiny percentage of living things became fossils!!

31. Relative dating estimates the time during which an organism lived.
Radiometric Dating:
Relative dating estimates the time during which an organism lived.
It compares the placement of fossils in layers of rock.
Radiometric dating uses decay of unstable isotopes.
Isotopes are atoms of an element that differ in their number of neutrons

32. Half-Lives

33. 12.2 The Geologic Time Scale
Index fossils can provide the relative age of a rock layer.
existed only during specific spans of time
occurred in large geographic areas
Index fossils include fusulinids and trilobites.
The history of Earth is represented in the geologic time scale.

34. Eras last tens to hundreds of millions of years.
consist of two or more periods
three eras: Cenozoic, Mesozoic, Paleozoic

37. Periods last tens of millions of years.
most commonly used units of time on time scale
associated with rock systems.
Epochs last several million years.

39. 12.3 Origin of Life
The most widely accepted hypothesis of Earth’s origins is the nebula hypothesis.
There are two organic molecule hypotheses.
Miller-Urey experiment: test input of E from light
meteorite hypothesis: off Australia, had 90aa found on Earth
electrodes
heat source
amino acids
water
“atmosphere”
“ocean”

40. There are different hypotheses of early cell structure.
iron-sulfide bubbles hypothesis
Martin/Russell proposed
Conditions needed for early life
lipid membrane hypothesis
Crucial step in the origin of life!

41. A hypothesis proposes that RNA was the first genetic material.
Ribozymes are RNA molecules that catalyze their own replication.
DNA needs enzymes to replicate itself.

42. 12.4 Early Single-Celled Organisms
Microbes have changed the physical and chemical composition of Earth.
The oldest known fossils are a group of marine cyanobacteria.
prokaryotic cells
added oxygen to atmosphere
deposited minerals

43. Fossil stromatolites provide evidence of early colonies of life.
Endosymbiosis is a relationship in which one organism lives within the body of another.
Mitochondria and chloroplasts may have developed through endosymbiosis.
Genetic variation is an advantage of sexual reproduction.
Sexual reproduction may have led to the evolution of multicellular life.

44. 12.5 Radiation of Multicellular Life
Life moved onto land during the Paleozoic Era.
Multicellular organisms first appeared during the Paleozoic era.
The era began 544 million years ago and ended 248 million years ago.
The Cambrian explosion led to a huge diversity of animal species.

45. Reptiles radiated during the Mesozoic era.
The Mesozoic era is known as the Age of Reptiles.
It began 248 million years ago and ended 65 million years ago.
Dinosaurs, birds, flowering plants, and first mammals appeared.

46. Mammals radiated during the Cenozoic era.
The Cenozoic era began 65 million years ago and continues today.
Placental mammals and monotremes evolved and diversified.
Anatomically modern humans appeared late in the era.

47. 12.6 Primate Evolution
Primates are mammals with flexible hands and feet, forward-looking eyes and enlarged brains.
Primates evolved into prosimians and anthropoids.
Prosimians are the oldest living primates.
They are mostly small and nocturnal.

48. Anthropoids are humanlike primates.
They are subdivided into the New World monkeys, Old World monkeys, and hominoids.
Homonoids are divided into hominids, great apes, and lesser apes.
Hominids include living and extinct humans.

49. Bipedal means walking on two legs.
foraging
carrying infants and food
using tools
Walking upright has important adaptive advantages.

50. Modern humans arose about 200,000 years ago.
Homo sapiens fossils date to 200,000 years ago.
Human evolution is influenced by a tool-based culture.
There is a trend toward increased brain size in hominids.
Australopithecus
afarensis
Homo habilis
Homo
neanderthalensis
Homo sapiens