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E&E
Some evidence for evolution
A. Direct Observation of Microevolution
• Adaptation and Speciation
• Natural Selection (many examples, a few covered previously)
B. The Fossil Record - gives us much information
• stratification of fossils
• dating of fossils, sediments
–
radiometric dating
– fission track dating
– electron spin resonance dating
– thermoluminescence dating
Sedimentary Layers – The Grand Canyon
Fossil Crinoid Stems and Brachiopods
A Trilobite (Odontochile formosa) from Lower Devonian of the
Kinglake district
(Source: Museum Victoria.)
(Trilobites lived from the Cambrian –
Permian; 545 – 251 mya)
Geologic Time Scale
Fission Track Dating of
Uranium
The fossil record yields…
• transitional/intermediate forms, vertebrate examples
(see http://www.talkorigins.org/faqs/faq-transitional.html for indepth treatment).
• pageant of whale (e.g. transitional Ambulocetus), and horse
evolution (Illustrated on the following slides.)
• many hominid transitions (e.g. Australopithecus is
transitional between Pan and Homo – we’ll study later)
• Archaeopteryx, Confuciousornis, Protopteryx are transitional
between reptiles and birds (Illustrated in a few slides.)
• Eusthenopteron (fish) is linked to the early amphibian
Icthyostega; Acanthostega
• Genera such as Probainognathus, Probelesodon and
Massetognathus (cynodonts) are transitional between reptiles
and mammals
Biogeographical
Evidence coupled
to fossil record
hummingbirds
marsupials
Quick note on the phenotype
Vp = Vg + Ve + Vg e
x
g e
p
A∙MX
B∙MY
A∙MX
A∙NY
Gradual versus punctuated evolution
• Gradual change
over time
• Branching,
punctuated change
Mesonychid – shared ancestry with whales
Ambulocetus
Rodhocetus, a predominantly aquatic whale from
the Eocene (47 mya)
Vestigial pelvis and femur in modern whales
Many dinosaur bones
have been found . . .
(Ultrasaurus)
Archaeopteryx
Comparative anatomy
Homology  having common ancestry but not necessarily
retaining similarity of structure or function
The Adult
Examples:
• Mammalian forelimbs (“hands”)
o grasping hands of primates
o digging hands of moles
o locomotive hands of horses
o paddles of porpoises
o wings of bats
• Vertebrate hindlimb structure
Hind Limb Structure in Vertebrates
Homo
sapiens
The Embryo
Bio-molecular Evidence
•Protein evidence
•Nucleic acid evidence
•Others…
RELATIVE LEVEL OF
SHARED CHARACTERISTICS AMONG SPECIES
DNA
Phylogeny
EVIDENCE FOR EVOLUTION
1. Fossil Record
2. Comparative Anatomy (phenotype)
physiology, anatomy, behavior, etc…
3. Biogeographical
4. Biochemical