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