What is evolution ?

Contributed by:
kevin
In biology, evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection.
1. Chapter Introduction
How do species
adapt to changing
environments
over time?
2. Chapter Introduction
What do you think?
Before you begin, decide if you agree
or disagree with each of these
statements.
As you view this presentation, see if
you change your mind about any of
the statements.
3. Chapter Introduction
Do you agree or disagree?
1. Original tissues can be preserved
as fossils.
2. Organisms become extinct only in
mass extinction events.
3. Environmental change causes
variations in populations.
4. hapter Introduction
Do you agree or disagree?
4. Variations can lead to adaptations.
5. Living species contain no evidence
that they are related to each other.
6. Plants and animals share similar
genes.
5. SWBATA
Fossil Evidence of
• How do fossils form?
• How do scientists date fossils?
• How are fossils evidence of biological
evolution?
6. Fossil Evidence of Evolution
• fossil record • geologic time
• mold scale
• extinction
• cast
• biological
• trace fossil
evolution
7. The Fossil Record
 The fossil record is made up of all the
fossils ever discovered on Earth.
 The fossil record provides evidence that
species have changed
over time.
 Based on fossil evidence,
scientists can recreate
the physical appearance
of species that are no
longer alive on Earth.
8. Fossil Formation
After an animal dies, any soft tissues animals do
not eat break down.
tissue
Science Use similar cells that
work together and perform a
function
Common Use a piece of soft,
absorbent paper
9. Fossil Formation (cont.)
 Only the dead animal’s hard parts, such as
bones, shells, and teeth, remain.
 Under rare conditions, these parts become
fossils.
10. Fossil Formation (cont.)
 The impression of an organism in a rock is
called a mold.
 A cast is a fossil copy of an organism in a rock.
11. Fossil Formation (cont.)
Atrace fossil is the preserved evidence
of the activity of an organism.
fossil
from Latin fossilis, means “to obtain
by digging”
12. Determining a Fossil’s Age
 Instead of dating fossils directly, scientists date
the rocks the fossils are embedded inside.
 In relative-age dating, scientists determine the
relative order in which rock layers were
deposited.
13. Determining a Fossil’s Age (cont.)
Relative-age dating helps scientists
determine the relative order in which
species have appeared on Earth over time.
How does relative-age dating help
scientists learn about fossils?
14. Determining a Fossil’s Age (cont.)
 Scientists take advantage of radioactive decay,
a natural clocklike process in rocks, to learn a
rock’s absolute age, or its age in years.
 To measure the age of sedimentary rock layers,
scientists calculate the ages of igneous layers
above and below them.
15. If the age of the
igneous layers
is known, it
is possible to
estimate the
age of the
sedimentary layers
the fossils
they contain—
between them.
16. Fossils over Time
The geologic time scale is a
chart that divides Earth’s history
into different time units.
Earth’s history is divided into four
eons—the longest time units in the
geologic time scale.
17. Lesson 1-4
18.
19. Date: Proterozoic Eon Event
By 1850 Ma Eukaryotic cells appear. Eukaryotes contain membrane-bound
organelles with diverse functions, probably derived from
prokaryotes engulfing each other via phagocytosis. (See
Endosymbiosis).[21][22]
By 1200 Ma Sexual reproduction first appears, increasing the rate of
evolution.[23]
1200 Ma Simple multicellular organisms evolve, mostly consisting of cell
colonies of limited complexity. First multicellular red algae
evolve
1100 Ma Earliest dinoflagellates
1000 Ma First alaeovaucheria
750 Ma First Melanocyrillium
580–542 Ma The Ediacaran biota represent the first large, complex
multicellular organisms - although their affinities remain a
subject of debate.[29]
560 Ma Earliest fungi
550 Ma First fossil evidence for ctenophora (comb-jellies), porifera
(sponges), and anthozoa (corals & anemones)
20. Date: Event in Paleozoic ERA
535 Ma Major diversification of living things in the oceans:
chordates, arthropods (e.g. trilobites, crustaceans),
echinoderms, mollusks, brachiopods, foraminifers and
radiolarians, etc.
510 Ma First cephalopods (Nautiloids) and chitons.
485 Ma First vertebrates with true bones (jawless fishes).
440 Ma First agnathan fishes: Heterostraci, Galeaspida, and
Pituriaspida.
420 Ma Earliest ray-finned fishes, trigonotarbid arachnids, and land
scorpions.
410 Ma First signs of teeth in fish. Earliest nautiid nautiloids,
lycophytes, and trimerophytes.
395 Ma First lichens, stoneworts. Earliest harvestman, mites,
hexapods (springtails) and ammonoids. The first known
tetrapod tracks on land.
350 Ma First large sharks, ratfishes, and hagfish.
330 Ma First amniote vertebrates (Paleothyris).
320 Ma Synapsids separate from sauropsids (reptiles) in late
Carboniferous.[37]
305 Ma Earliest diapsid reptiles (e.g. Petrolacosaurus).
21. Date Event during Mesozoic Era
245 Ma Earliest ichthyosaurs.
220 Ma first turtles (Odontochelys).
200 Ma Earliest examples of Ankylosaurian dinosaurs
195 Ma First pterosaurs with specialized feeding (Dorygnathus)
190 Ma First lepidopteran insects (Archaeolepis)
176 Ma First members of the Stegosauria group of dinosaurs
161 Ma Ceratopsian dinosaurs appear in the fossil record (Yinlong)
155 Ma First blood-sucking insects (ceratopogonids), rudist bivalves, and
cheilosome bryozoans. Archaeopteryx, a possible ancestor to the
birds, appears in the fossil record, along with triconodontid and
symmetrodont mammals. Diversity in stegosaurian and theropod
dinosaurs.
130 Ma The rise of the Angiosperms: These flowering plants boast structures
that attract insects and other animals to spread pollen. This
innovation causes a major burst of animal evolution through
co-evolution. First freshwater pelomedusid turtles.
115 Ma First monotreme mammals.
110 Ma First hesperornithes, toothed diving birds. Earliest limopsid,
verticordiid, and thyasirid bivalves.
106 Ma Spinosaurus, the largest theropod dinosaur, appears in the fossil
record.
100 Ma Earliest bees.
70 Ma Multituberculate mammals increase in diversity.
68 Ma Tyrannosaurus, the largest terrestrial predator of North America
22. Date Event in Cenozoic Era
63 Ma Evolution of the creodonts, an important group of
carnivorous mammals.
56 Ma Gastornis, a large, flightless bird appears in the
fossil record, becoming an apex predator at the
time.
40 Ma Basilosaurus, one of the first of the giant whales,
appeared in the fossil record.
28 Ma Paraceratherium appears in the fossil record, the
largest terrestrial mammal that ever lived.
25 Ma First deer.
4.8 Ma Mammoths appear in the fossil record.
4 Ma Evolution of Australopithecus,
2.5 Ma The earliest species of Smilodon evolve
350 ka Evolution of Neanderthals
200 ka Modern humans appear in Africa.
23.  Extinction occurs when the last
individual organism of a species dies.
 A mass extinction occurs when many
species become extinct within a few
million years or less.
 Extinctions can occur when
environments change.
24. Extinctions (cont.)
The fossil record contains evidence that five mass
extinction events have occurred during the
Phanerozoic eon.
25. Extinctions (cont.)
 The fossil record contains evidence of
the appearance of many new species
over time.
 Biological evolution is the change over
time in populations of related organisms.
26. The fossil record is
that horses
descended from
organisms for
which only fossils
exist today.
27. Extinctions (cont.)
How are fossils evidence
of biological evolution?
28. • Fossils can consist of the hard parts or
soft parts of organisms. Fossils can be
an impression of an organism or
consist of original tissues.
• Scientists determine
the age of a fossil
through relative-age
dating or absolute-
age dating.
29. • Scientists use
fossils as evidence
that species have
changed over time.
30. Theory of Evolution by
Natural Selection
• Who was Charles Darwin?
• How does Darwin’s theory of evolution
by natural selection explain how
species change over time?
• How are adaptations evidence of
natural selection?
31. Theory of Evolution by
Natural Selection
• naturalist • camouflage
• variation • mimicry
• natural selection • selective
• adaptation breeding
32. Charles Darwin
 A naturalist is a person who studies
plants and animals by observing them.
 Charles Darwin was an English naturalist
who, in the mid-1800s, developed a
theory of how evolution works.
33. Darwin found that each island in the
Galápagos had a different environment, and
tortoises looked different depending on
which island environment they inhabited.
34.  A variation is a slight
difference in an
inherited trait of
individual members
of a species.
 Variations arise
naturally in
populations,
occurring in offspring
as a result of sexual
reproduction.
 Genetic changes to
phenotype can be
passed on to future
generations.
35. How Evolution Occurs- 4 Steps
1 – Reproduction: More offspring are produced than
can ever survive
2- Variation: Exists within the group of offspring due
to sexual reproduction (meiosis and fertilization)
3- Competition: Offspring compete with one another
and other species for resources (food, shelter, mates
4- Selection: The environment determines which one
competed the best and has a chance to survive and
pass on its successful genes(alleles)!
36. Natural Selection
37. Darwin’s Theory (cont.)
 Natural selection is the process by
which populations of organisms with
variations that help them survive in their
environments live longer, compete
better, and reproduce more than those
that do not have the variations.
38. Adaptations
 An adaptation is an inherited trait that
increases an organism’s chance of surviving
and reproducing in its environment.
Structural -color, shape, and other
physical characteristics.
Behavioral-the way an organism
behaves or acts.
Functional-internal body systems
that affect biochemistry.
39. Adaptations (cont.)
 Camouflage and mimicry are adaptations that
help species avoid being eaten.
 Camouflage is an adaptation that enables a
species to blend in with its environment.
 The resemblance of one species to another
species is mimicry.
40. Artificial Selection
 The breeding of organisms for desired
characteristics is called selective
breeding.
 Darwin realized that changes caused by
selective breeding were much like
changes caused by natural selection.
41. 1.How does natural selection relate to
evolution of a species?
2.List the three types of adaptations.
3.What is the difference between
camouflage and mimicry?
42. • Charles Darwin developed his theory
of evolution partly by observing
organisms in their natural
environment.
• Natural selection occurs
when organisms with
certain variations live
longer, compete better,
and reproduce more often
than organisms that do
not have the variations.
43. • Adaptations occur when a beneficial
variation is eventually inherited by all
members of a population.
44. Lesson 2 – LR1
Which refers the process by which
populations of organisms with
variations that help them survive in
their environments live longer, compete
better, and reproduce more than those
that do not have the variations?
A. adaptation
B. mimicry
C. natural selection
D. selective breeding
45. Lesson 2 – LR2
Which is an inherited trait that
increases an organism’s chance
of surviving and reproducing in
its environment?
A. adaptation
B. camouflage
C. natural selection
D. variation
46. Lesson 2 – LR3
What term refers to the breeding
of organisms for desired
A. adaptation
B. variation
C. natural selection
D. selective breeding
47. Terms to Know…
 comparative anatomy
 homologous structure
 analogous structure
 vestigial structure
 embryology
48. Some funny pictures of apes!
49.
50.
51. Oh no…Mr. Ollive is
going to make us take
notes now!
52. SWBATA
Biological Evidence of Evolution
• What evidence from living species
supports the theory that species
descended from other species over
time?
• How are Earth’s organisms related?
53. Evidence for Evolution
 The degree to which species are related
depends on how closely in time they diverged,
or split, from their common ancestor.
 Although the fossil record is incomplete, it
contains many examples of fossil sequences
showing close ancestral relationships.
54. The fossil record
indicates that
different species
of horses often
overlapped with
each other.
55. Evidence for Evolution (cont.)
 Comparative anatomy is the study of
similarities and differences among structures of
living species. ( Comparing and Anatomy)
 Homologous structures are body parts of
organisms that are similar in structure and
position but different in function.
56. The forelimbs of these species are different sizes,
but their placement and structure suggest
common ancestry.
57. Body parts that perform a
similar function but differ
in structure are
analogous structures.
Organisms evolve to
the environment in
similar ways! Wings
and fins are perfect
58. Vestigial structures are body parts that have lost their
original function through evolution.
59. Evidence for Evolution (cont.)
The science of the development of embryos from
fertilization to birth is
called embryology.
60. All vertebrate embryos exhibit pharyngeal pouches
at a certain stage of their development. These
features, which develop into neck and face parts,
suggest relatedness.
61.  How do homologous structures provide
evidence for evolution?
 How are vestigial structures evidence of
descent from ancestral species?
 How do pharyngeal pouches provide
evidence of relationships among
species?
62. Evidence for Evolution (cont.)
 Molecular biology is the study of gene structure
and function.
 Discoveries have confirmed and extended much
of the data already collected about the theory
of evolution.
 Scientists can study relatedness of organisms
by comparing genes and proteins among living
species.
63. Evidence for Evolution (cont.)
 Organisms with similar DNA share common
ancestors and are closely related
64.
65. Divergence – to split apart
Molecular data indicate
that whales and
porpoises are more
closely related to
hippopotamuses than
they are to any other
living species.
66. The Study of Evolution Today
 New evidence supporting the theory
of evolution by natural selection is discovered
nearly every day, but scientists debate some of
the details.
 New fossils that have features of species that
lived both before them and after them help
scientists study more details about the origin of
new species.
67. Many scientists think that natural selection produces
new species slowly and steadily.
Other scientists think species exist stably for
long periods, and change occurs in short bursts.
68. • By comparing the
anatomy of
organisms and
looking for
homologous
or analogous
structures,
scientists can
determine if
organisms had a
common ancestor.
69. • Some organisms have vestigial
structures, suggesting that they
descended from a species that used
the structure for a purpose.
70. • Scientists use evidence
from developmental and
molecular biology to help
determine if organisms
are related.
71. The BIG Idea
Through natural
selection, species
evolve as they adapt
to Earth’s changing
environments.
72. Lesson 1: Fossil Evidence of Evolution
Key Concepts 1
 Fossils form in many ways, including mineral
replacement, carbonization, and impressions
in sediment.
 Scientists can learn the ages
of fossils by techniques of
relative-age dating and
absolute-age dating.
 Though incomplete, the fossil
record contains patterns suggesting the
biological evolution of related species.
73. Lesson 2: Theory of Evolution by Natural Selection
 The 19th century naturalist Charles Darwin
developed
a theory of evolution that is still studied today.
 Darwin’s theory of evolution by natural
selection is the process by which
populations with variations that help them
survive in their environments live longer
and reproduce more than those without
beneficial variations. Over time, beneficial
variations spread through populations, and new
species that are adapted to their environments
evolve.
 Camouflage, mimicry, and other adaptations are
evidence of the close relationships between species
74. Lesson 3: Biological Evidence
of Evolution
 Fossils provide only one source
of evidence of evolution.
Additional evidence comes from
living species, including studies
in comparative anatomy,
embryology, and molecular
biology.
 Through evolution by natural
selection, all of Earth’s
organisms are related. The
more recently they share a
common ancestor, the more
closely they are related.
75. Lesson 1 – LR1
Which refers to a chart that
divides Earth’s history into
different time units?
A. fossil record
B. geologic time scale
C. relative-age dating
D. trace fossil
76. Lesson 1 – LR2
Which is the preserved evidence
of the activity of an organism?
A. cast
B. fossil record
C. mold
D. trace fossil
77. Which term describes the
collection of all the fossils ever
discovered on Earth?
A. cast
B. mold
C. fossil record
D. trace fossil
78. Which is a fossil copy of an
organism in a rock?
A. cast
B. mold
C. fossil record
D. trace fossil
79. What kind of adaptation enables
a species to blend in with its
A. camouflage
B. mimicry
C. behavioral adaptation
D. functional adaptation
80. What kind of adaptations involve
internal body systems that affect
A. mimicry
B. variation
C. behavioral adaptations
D. functional adaptations
81. Which of these is the study of
gene structure and function?
A. embryology
B. variation
C. comparative anatomy
D. molecular biology
82. Which term describes what
happens when the last individual
organism of a species dies?
A. adaptation
B. extinction
C. biological evolution
D. mass extinction
83. What describes one species’
resemblance to another species?
A. adaptation
B. camouflage
C. mimicry
D. variation
84. What type of adaptation involves
the way an organism behaves or
A. mimicry
B. variation
C. behavioral adaptation
D. structural adaptation
85. What term refers to body parts
of organisms that are similar in
structure and position but
different in function?
A. camouflage
B. mimicry
C. analogous structures
D. homologous structures
86. Lesson 3 – LR1
What term refers to body parts
that perform a similar function
but differ in structure?
A. analogous structures
B. homologous structures
C. pharyngeal pouches
D. vestigial pelvis
87. Lesson 3 – LR2
What is the name for the science
of the development of embryos
from fertilization to birth?
A. adaptation
B. embryology
C. comparative anatomy
D. molecular biology
88. Lesson 3 – LR3
Which describes the study of
similarities and differences among
structures of living species?
A. adaptation
B. embryology
C. comparative anatomy
D. molecular biology