Download File - The Science of Payne

10.1 Early Ideas About Evolution
KEY CONCEPT
There were theories of biological and geologic
change before Darwin.
10.1 Early Ideas About Evolution
Early scientists proposed ideas about evolution.
• Evolution is the biological change process by which
descendants come to differ from their ancestors.
• A species is a group of organisms that can reproduce
and have fertile offspring.
10.1 Early Ideas About Evolution
• There were many important naturalists in the 18th century.
– Linnaeus: classification system from kingdom to species
– Buffon: species shared ancestors rather than arising
separately
– E. Darwin: more-complex forms developed from lesscomplex forms
– Lamarck: environmental change leads to use or disuse
of a structure
10.1 Early Ideas About Evolution
Theories of geologic change set the stage for Darwin’s
theory.
• There were three theories of geologic change.
– catastrophism
– gradualism
– uniformitarianism
10.1 Early Ideas About Evolution
• Uniformitarianism is the prevailing theory of
geologic change.
10.1 Early Ideas About Evolution
• What term describes the theory that natural disasters
shaped Earth's landforms and caused species to
become extinct?
• Which scientist developed a classification system
based on similarities?
• Which theory of geologic change is accepted by today's
scientists?
10.4 Evidence of Evolution
KEY CONCEPT
Evidence of common ancestry among species comes
from many sources.
10.4 Evidence of Evolution
Evidence for evolution in Darwin’s time came from
several sources.
• Fossils provide evidence of evolution.
• Fossils in older layers are more primitive than
those in the upper layers.
Section 2 Evidence of
10.4 Evidence
of
Evolution
Chapter 15
Evolution
The Fossil Record, continued
• Transitional Species
– Fossils of transitional species show evidence of
descent with modification.
Section 2 Evidence of
10.4 Evidence
of
Evolution
Chapter 15
Evidence of Whale
Evolution
Evolution
10.4 Evidence of Evolution
• The study of geography provides evidence of evolution.
– island species most closely resemble nearest mainland
species
– populations can show variation from one island to
another
10.4 Evidence of Evolution
• Embryology provides evidence of evolution.
– identical larvae, different adult body forms
– similar embryos, diverse organisms
Larva
Adult crab
Adult barnacle
10.4 Evidence of Evolution
10.4 Evidence of Evolution
• The study of anatomy provides evidence of evolution.
– Homologous structures are similar in structure but
different in function.
– Homologous structures are evidence of a common
ancestor.
Human hand
Mole foot
Bat wing
10.4 Evidence of Evolution
• The study of anatomy provides evidence of evolution.
– Analogous structures have a similar function.
Human hand
foot
– Analogous structures are Mole
not evidence
of a common
ancestor.
Fly wing
Bat wing
10.4 Evidence of Evolution
Structural patterns are clues to the history of a species.
• Vestigial structures are remnants of organs or structures
that had a function in an early ancestor.
• Ostrich wings are examples of vestigial structures.
10.4 Evidence of Evolution
• What term describes features that are similar in
structure but different in function?
• In which rock layer would you expect to find the most
primitive fossils?—Top, middle, bottom
• The embryos of many kinds of animals have gill slits.
Gill slits develop into gills in fish and into ears of
mammals. What do these common structures
indicate?
• Describe analogous structures?
10.5 Evolutionary Biology Today
KEY CONCEPT
New technology is furthering our understanding of
evolution.
10.5 Evolutionary Biology Today
Fossils provide a record of evolution.
• Paleontology is the study of fossils or extinct organisms.
10.5 Evolutionary Biology Today
• Paleontology provides evidence to support evolution.
10.5 Evolutionary Biology Today
Molecular and genetic evidence support fossil and
anatomical evidence.
• Two closely-related organisms will have similar DNA
sequences.
10.5 Evolutionary Biology Today
• Pseudogenes are sequences providing evidence of
evolution.
– no longer function
– carried along with functional DNA
– can be clues to a common ancestor
10.5 Evolutionary Biology Today
• Hox genes indicate a very distant common ancestor.
– control the development of specific structures
– found in many organisms
• Protein comparisons, or molecular fingerprinting reveals
similarities among cell types of different organisms.
10.5 Evolutionary Biology Today
Evolution unites all fields of biology.
• Scientist from any fields contribute to the understanding
of evolution.
• The basic principles of evolution are used in many
scientific fields.
10.5 Evolutionary Biology Today
• What is a transitional fossil?
• What can be learned about evolution from DNA
sequencing?
• Why is the fossil record incomplete?
• Suppose scientists found a fossil of a dinosaur that
had feathers. What evolutionary information can be
inferred from this fossil?
17.2 Classification Based on Evolutionary Relationships
KEY CONCEPT
Modern classification is based on evolutionary
relationships.
17.2 Classification Based on Evolutionary Relationships
Cladistics is classification based on common ancestry.
• Phylogeny is the evolutionary history for a group of species.
– evidence from living species, fossil record, and
molecular data
– shown with branching tree diagrams
17.2 Classification Based on Evolutionary Relationships
• Cladistics is a common method to make evolutionary trees.
– classification based on common ancestry
– species placed in order that they descended from
common ancestor
17.2 Classification Based on Evolutionary Relationships
• A cladogram is an evolutionary tree made using cladistics.
– A clade is a group of species that shares a common
ancestor.
– Each species
in a clade
shares some
traits with the
ancestor.
– Each species
in a clade has
traits that have
changed.
17.2 Classification Based on Evolutionary Relationships
• Derived characters are traits shared in different degrees by
clade members.
1 Tetrapoda clade
– basis of arranging
species in
cladogram
– more closely
related species
share more
derived characters
– represented on
cladogram as hash
marks
2 Amniota clade
3 Reptilia clade
4 Diapsida clade
5 Archosauria clade
FEATHERS &
TOOTHLESS
BEAKS.
SKULL OPENINGS IN
FRONT OF THE EYE &
IN THE JAW
OPENING IN THE SIDE OF
THE SKULL
SKULL OPENINGS BEHIND THE EYE
EMBRYO PROTECTED BY AMNIOTIC FLUID
FOUR LIMBS WITH DIGITS
DERIVED CHARACTER
17.2 Classification Based on Evolutionary Relationships
• Nodes represent
the most recent
common ancestor
of a clade.
CLADE
1 Tetrapoda clade
2 Amniota clade
3 Reptilia clade
4 Diapsida clade
• Clades can be
identified by
snipping a branch
under a node.
5 Archosauria clade
FEATHERS AND
TOOTHLESS
BEAKS.
SKULL OPENINGS IN
FRONT OF THE EYE AND
IN THE JAW
OPENING IN THE SIDE OF
THE SKULL
SKULL OPENINGS BEHIND THE EYE
EMBRYO PROTECTED BY AMNIOTIC FLUID
NODE
FOUR LIMBS WITH DIGITS
DERIVED CHARACTER
17.2 Classification Based on Evolutionary Relationships
Molecular evidence reveals species’ relatedness.
• Molecular data may confirm classification based on
physical similarities.
• Molecular data may lead scientists to propose a new
classification.
• DNA is usually given the last word by scientists.
10.1 Early Ideas About Evolution
• What does a cladogram show?
• What is true about two organisms that share the same
common ancestor?
• What is true about the organisms that branch off after a
hash mark on a cladogram?
• What does a node represent on a cladogram?