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Evidence of Evolution
Beyond the Fossil Record
How Does Anatomy and Structure
Show Evidence of Ancestry?
Comparing the anatomy of different types
of organisms often reveals basic
similarities in body structures, even though
their functions may be very different.
Common Ancestor
• A Species from which two or more species
have diverged.
Covergent Evolution
Homologous Structures
• Structures that share common
ancestry.
Analogous Structures
• Analogous structures have similar forms,
but they are not due to common ancestry.
Vestigial Structures
• Vestigial structures are anatomical
structures of organisms in a species,
which have lost much or all of their
original function.
• Structures that are considered to be
evidence for an organisms
evolutionary past.
Flightless Cormorant of the Galapagos
Vestigial Pelvis of the Whale
Femur and Pelvis of Whale
How is Embryonic Development
Evidence for Evolution?
• The evolutionary history of organisms is
seen in the development of embryos.
What are some common
structures that vertebrate
embryos share?
• Tail bud
• Pharyngeal pouches
• Buds that become limbs
How are Biological Molecules a Record
of Evolution?
Species that share common ancestry
more closely, have more amino acid
sequence in common.
Species that have diverged from a distant
common ancestor have more differences
in amino acid sequences.
The Hemoglobin Protein shows common ancestry.
Hemoglobin Comparison
Species
Amino acid differences
Gorilla
1
Rhesus monkey
8
Mouse
27
Chicken
45
Frog
67
Lamprey
125
Great Moments in Evolution