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
