about the evidence of evolution from fossils to dna and rna.

2. “Evolve” Means to
Change Over Time

3. EVIDENCE Of
EVOLUTION
Essential idea: There is overwhelming
evidence for the evolution of life on
Earth.
This image of a fossilized
primitive vascular plant called a
horsetail. Fossils are just one
example of evidence for
evolution along with homologous
structures, the universality of
DNA, and antibiotic resistance.

4. The Development of Evolutionary TheoryThe Development of Evolutionary Theory
Naturalists have always wondered at theNaturalists have always wondered at the
diversity of living things………diversity of living things………
Great varieties in shape, size, and ecological role
Estimated 3 million to 20 million different living species
Much of the natural world’s biodiversity has vanished
through extinction.
99% of all species that ever lived are now extinct
Permian-Triassic Mass Extinction
What Killed the Dinosaurs?

5. The Permian–Triassic (P Tr) extinction
event, colloquially known as the Great
Dying, the End Permian or the Great
Permian Extinction, occurred about
252 Ma(million years) ago, forming the
boundary between the Permian
and Triassic geologic periods, as well as
the Paleozoic and Mesozoic eras.

6. Development of Evolutionary TheoryDevelopment of Evolutionary Theory
What could cause such great diversity, andWhat could cause such great diversity, and
why have so many species died out?why have so many species died out?

7. English naturalist and geologist, best known for his
contributions to the science of evolution.
Darwin published his theory of evolution with compelling
evidence in his 1859 book O n the O rig in o f Spe cie s ,
overcoming scientific rejection of earlier concepts
of transmutation of species. By the 1870s,
the scientific community and much of the general
public had accepted evolution as a fact. However,
many favored competing explanations and it was not
until the emergence of the modern evolutionary
synthesis from the 1930s to the 1950s that a broad
consensus developed in which natural selection was
the basic mechanism of evolution. In modified form,

8. Development of Evolutionary TheoryDevelopment of Evolutionary Theory
Darwin Concluded:
Physical traits and behaviors enable
organisms to survive and reproduce (called
Fitness )
Fitness results from adaptations
Darwin reasoned that adaptations result from
natural selection and result in evolution
Evolution is the process by which living thingsEvolution is the process by which living things
change and diversify over timechange and diversify over time

9. Development of Evolutionary Theory
These ideas were widely challenged
until a tremendous amount of evidence
was gathered to support evolution!
Now…The Theory of Evolution is the
Cornerstone of Biology

11. The Origin of Life
Geology
The Fossil Record
Comparative Embryology
Comparative Biochemistry
Comparative Anatomy
Isn’t Evolution Just a Theory?
Scientists from many disciplines including
biology, chemistry, physics, geology, and
paleontology have contributed to the case
for evolution!

12. The Origin of Life
Origin of the Universe
Big Bang (animation)
Early Earth
Evolution Starts Up: Chemical Evolution
Heterotroph Hypothesis: Molecules of life
arose from inorganic building blocks

13. The Miller-Urey Experiment
Studied Molecules Present at Time of
Early Earth
Methane, Ammonia, Carbon
Dioxide, Water Vapor
Mixed Molecules in Reaction Chamber
Sparked with Electricity to Simulate
Lightning
Exposed Mixture to UV Radiation to
Simulate Cosmic Rays
Produced Basic Amino Acids and
Organic Molecules

14. Miller-Urey
Apparatus

15. Biological Evolution
RNA as a information molecule and
catalyst
Endosymbiotic Theory
Mitochondria and chloroplasts were
originally free living prokaryotic cells
Both have own DNA and ribosomes
Joined together to cooperate

16. Geology
The Study of the Earth and Rocks
Early Ideas About Earth:
People believed Earth was only a few
thousand years old
People believed that rocks and geological
features were shaped by catastrophic
events and rarely changed

17. Geology
In the 18th
and 19th
Century Scientists Studied
Geology in Great Detail
Over millions of years 1 original continent
Pangea drifted apart to make our modern
continents
Continental drift is gradual “gradualism”

18. Geology
Hutton and Lyell:
Earth is Changed
by Weather and
Natural
Processes like
Volcanoes and
Erosion
Takes a Very
Long Time!

19. Geology
These ideas refute the idea that the Earth is
only a few thousand years old
Backed up by radiometric dating
The Earth is approximately 4.6 Billion Years Old
4,600,000,000 years is a long time!

20. The Fossil Record
Fossils are the preserved remains
of ancient organisms
Provide information about past
organisms
Shows that many diverse organisms
lived at different times in Earth’s
History

21. The Fossil Record
Taphonomy: The Formation of Fossils
Fossils form in sedimentary rock
Dead organisms covered by sand and silt
Sediments are passed into bone by
pressure from above (fossils form in
sedimentary rock)
Video

22. Determining the Age of Fossils
Relative Dating: Technique used by
scientists to determine the age of fossils
relative to fossils in other layers of rock
Different layers represent different geologic
periods
Older fossils found in lower layers, newer
fossils found in upper layers
Cannot determine the actual age of the
fossil!

23. Determining the Age of Fossils
Radioactive Dating: Process by which traces of
radioactive elements are analyzed to calculate the
actual age of a fossil
Many radioactive elements can be used as
geologic clocks. Each radioactive element decays
at its own nearly constant rate. Once this rate is
known, geologists can estimate the length of time
over which decay has been occurring by
measuring the amount of radioactive parent
element and the amount of stable daughter
elements
Video

24. Radiometric Dating
Radioactive
Parent
Stable
Daughter
Half life
Potassium 40 Argon 40
1.25 billion
yrs
Rubidium 87
Strontium
87
48.8 billion
yrs
Thorium 232 Lead 208
14 billion
years
Uranium 235 Lead 207
704 million
years
Uranium 238 Lead 206
4.47 billion
years
Carbon 14 Nitrogen 14 5730 years

25. The Geologic Time Scale
Based on fossil and geologic evidence
A record of the Earth’s past
Divided into Era, Period, and Epoch
Shows that life on Earth followed geologic
change on Earth
Deep Time Activity
Interactive Time Scale

26. Comparative Embryology
Embryos are organisms at early stages
of development

27. Comparative Embryology
All vertebrate embryos,
including humans, share
features
Eye spot
• (Evolution of the Human Eye)
Gill pouches
Notochord
Shows similar genetic
ancestry
Video

28. Comparative Biochemistry
All life is based on organic chemistry
Carbon based compounds
All life uses same molecule as blueprint
DNA
Similar chemical processes
Bacteria, algae, and plants all do photosynthesis
Similar organisms have similar genetic code
Humans and chimpanzees share nearly identical
genes (98.4% identical gene sequences) Video

29. Anatomy and Comparative Anatomy
Vestigial Organs
Organs inherited but not used by modern
organisms
Present but greatly reduced in modern
organisms
Hip bone in python
Appendix in human
Tail bone (cocyx) in human

30. Anatomy: Homologous Structures
Similar parts of different organisms,
often quite dissimilar in purpose, that
developed from the same ancestral
body parts (Video)
Divergent evolution

31. Anatomy: Analogous Structures
Similar in purpose, but not inherited
from a recent common ancestor
Environment selected for trait
Wings of birds and insects
Convergent evolution

32. Summary
There is overwhelming evidence to
support the Theory of Evolution
Evidence comes from disciplines as
varied as biology, geology, chemistry,
physics, astronomy, and paleontology
Evolution has produced the great
beauty and diversity of life on Earth
over the last 4 billion years

33. NaturalSe le ctio n
and Spe ciatio n

34. Charles Darwin
Studied Medicine and Theology
Excelled in Geology and Biology
In 1831 Darwin joined the H.M.S.
Beagle on a trip around the world to
make maps
He was the ship’s naturalist
Darwin’s Diary

35. The Voyage of the Beagle: Ports of
Call
Noted that populations of organisms were slightlyNoted that populations of organisms were slightly
different from place to placedifferent from place to place
Each group was modified to their specific environmentEach group was modified to their specific environment

36. The Galapagos ArchipelagoThe Galapagos Archipelago

37. Land Iguana
Marine Iguana

41. The Origin of Species Interactive Exploration

42. Evolution Through Natural Selection
There is variation in populations caused byThere is variation in populations caused by
geneticsgenetics (Praying Mantis Camouflage)(Praying Mantis Camouflage)
Many more offspring are produced than canMany more offspring are produced than can
survive. Many die through predation or starvationsurvive. Many die through predation or starvation
Some variations are favorable and helpSome variations are favorable and help
organisms compete to survive and reproduceorganisms compete to survive and reproduce
Over time, the organisms with favorableOver time, the organisms with favorable
variations become plentiful. The ones withoutvariations become plentiful. The ones without
favorable variations become rare or extinctfavorable variations become rare or extinct
Reluctantly publishedReluctantly published On the Origin of SpeciesOn the Origin of Species inin
18591859
VideoVideo

43. Speciation
Natural Selection modifies populations.
Some evolutionary changes are so
great that some organisms can no
longer interbreed with the original
population
A new species results
Species
An interbreeding population of organisms
that can produce healthy, fertile offspring

44. Reproductive Barriers and Speciation
Prezygotic: gametes never meet and fuse
Geographic isolation (allopatric speciation)
Ecological isolation
Behavioral isolation (lacewing songs)
Mechanical isolation
Seasonal isolation
Postzygotic: genetic differences manifest
Hybrid inviability
Hybrid sterility (tigons and ligers)

45. Patterns in Evolution
Adaptive Radiation
Development of numerous new species from a
common ancestor in diverse environments
Darwin’s Finches (Origin of Species Activity)
Gradualism
Punctuated Equilibrium

46. Evolution Produces Diversity
All living things are classified by characteristics
into 5 kingdoms of life
Monera: bacteria, unicellular prokaryotes
Protista: single celled eukaryotes
Fungi: multicellular, eukaryotic, nonmotile, heterotrophs
Plantae: multicellular, eukaryotic, autotrophs
Animalia: multicellular, eukaryotic, motile, heterotropohs

47. Linnean Taxonomy
Example: human classification
Kingdom animalia
Phylum chordata
Class mammalia
Order primate
Family hominid
Genus homo
Species sapiens
Binomial nomenclature uses genus and
species to make the scientific name
Homo sapiens
Classification activity

48. Human Evolution

49. Explore Human Evolution
View the Becoming Human broadband
documentary
As you view each segment, visit the related
exhibits to further explore this topic
Go to the Learning Center and select the
“Calculating Cousins” activity
Go to the Learning Center and select the
“Chromosome Connection” activity
Go to the Learning Center and select the
“Building Bodies” activity

50. The Order Primate
Characteristics of Primates
Strong hands and opposable thumbs
Free-moving shoulder joint
Forward facing eyes and stereoscopic vision
Intelligence/larger brain
Social complexity

51. What Characteristics do Humans Have?
All of those of primates, plus
Upright posture and bipedal
Use of tools and technology
Advanced intelligence
Complex communication and speech

52. The Steps to Human Evolution
Terrestrialization
Bipedal (Walking on all two’s)
Increased Brain Size
Civilization
Take a look at the Human family tree

53. The Hominid Family
Each year new fossils are found to add
to the Hominid family tree
Most fossils of early humans are found
in Africa and lower Asia
Most well understood members include
genus Australopithecus (extinct) and
genus Homo
Solve the Riddle of the Bones

54. Genus Australopithecus
First human ancestor to live on the
ground and walk on two legs
As evidenced by the Laetoli footprints
Ape-like jaw
Small brain
Short stature
Found only in South and East Africa

55. The Australopithecines
A. anamesis 4 MYA
A. afarensis 3.2 MYA (Finding “Lucy”)
A. africanus 2.5 MYA
A. robustus 2 MYA
A. boisei 2 MYA

56. Genus Homo
More modern hominids that exhibited major
evolutionary steps
Increased brain size
Use of tools
Use of fire
Use of shelter
Religion
Language and civilization

57. Homo habilis “The Tool Man”
Approx. 2.5 MYA
Brain ½ size of
modern human
First to make and
use stone tools and
weapons

58. Homo erectus “The Upright Man”
Direct ancestor of
modern humans
Widespread in Africa
and Asia by 1 MYA
Evidence of use of
shelter and fire

59. Homo sapiens “The Wise Man”
Most likely evolved from H. erectus as early
as 400,000 years ago
Greatly increased brain size
Consisted of 2 groups
Neanderthal
Cro-Magnon/modern H. sapiens

60. Neanderthals
Found in Neander Valley in Germany
Fossils found throughout Europe,
Middle East, and Asia from 150,000-
30,000 years ago
Large bodies and brains
Evidenced painting, religion, complex
social structure
“Cave man”

61. Cro Magnons and Fully Modern Humans
First early modern H. sapiens appear about
130,000 years ago
Thinner bones, smaller jaws, higher skull
with little or no brow ridge, and larger brains
Cave art shows complex religion and culture
Lived alongside Neanderthal for several
thousand years, but eventually out-competed
them