1. AP Biology – Lecture #4
Big Idea #1 – Evolution Change in the genetic makeup of a population over time IS evolution.
Adapted from Rebecca Rehder Wingerden ©

2. Biological evolution is supported by scientific evidence from many disciplines, including mathematics.
Scientific evidence of biological evolution uses information from geographical, geological, physical, chemical and mathematical applications.
Molecular, morphological and genetic information of existing and extinct organisms add to our understanding of evolution.
Hierarchical classification: At each level
of the Linnaean classification system,
species are placed into groups belonging
to more comprehensive groups.

3. Biological evolution is supported by Fossils.
Fossils can be dated by a variety of methods that provide evidence for evolution.
These include the age of the rocks (1) where a fossil is found,
Law of superposition, “relative” age of fossils

4. Biological evolution is supported by Fossils.
The (2) rate of decay of isotopes (radiometric dating) including:
Carbon-14 with a half life of 5730 years
Uranium-238 with a half life of 4.56 billion
“Absolute” ages of fossils can be determined by radiometric dating.
Geologist can apply an indirect method to infer the absolute age of fossils.
Bozeman Biology: Radiocarbon
Dating (10:00 min.)

5. Biological evolution is supported by Fossils.
And the mathematical calculations that take into account information from (3) chemical properties and/or geographical data.
molecular clock - method compares the amount of genetic difference between living organisms and computes an age based on well-tested rates of genetic mutation over time
Biochronology - age
estimate based on the
fauna arrangement
(younger to older), used
when sites that cannot be
readily dated, the animal
species found there can be
compared to well-dated
species from other sites.
Number of Mutations
Divergence Time (millions of years)

6. Biological evolution is supported by morphological homologies.
Morphological homologies represent features shared by common ancestry.

7. Biological evolution is supported by morphological homologies.
Vestigial structures are remnants of functional structures, which can be compared to fossils and provide evidence for evolution.
Skeletons of cetaceans and some snakes retain vestiges of the pelvis and leg bones of walking ancestors

8. Biological evolution is supported by genetics.
Biochemical and genetic similarities, in particular DNA nucleotide and protein sequences, provide evidence for evolution and ancestry.
The same genetic code:
DNA, RNA, Protein
Synthesis
(molecular systematics)
Aligning segments of DNA: Systematists use
computer software to find and align similar
sequences of DNA segments from two species.

9. Biological evolution is supported by mathematics.
Mathematical models and simulations can be used to illustrate and support evolutionary concepts.
Construction of phylogenetic trees based on sequence data
Bozeman Science Recap – Models
004-evidence-for-evolution
Bozeman Science Recap:
evidence-for-evolution-ii

10. Phylogenetic Trees show evolutionary relatedness

11. Constructing a Phylogenetic Tree
shared ancestral character - backbone (originated in an ancestor)
shared derived characteristic – hair in mammals (evolutionarily unique to a particular group, or clade)

12. Constructing a Phylogenetic Tree
How To Build A Cladogram nu/cladograms/Open-This-File.swf Or