selection and evolution
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Selection and Evolution. Jory Weintraub, Ph.D. National Evolutionary Synthesis Center (NESCent). Where Do I Work? National Evolutionary Synthesis Center (NESCent). What is Evolution?. CHANGE OVER TIME… It explains the diversity of life on Earth!. Evolution = Change Over Time. - PowerPoint PPT PresentationTRANSCRIPT
Selection and Evolution
Jory Weintraub, Ph.D.National Evolutionary Synthesis Center (NESCent)
Where Do I Work?National Evolutionary Synthesis
Center (NESCent)
What is Evolution?
CHANGE OVER TIME…
It explains the diversity of life on Earth!
Evolution = Change Over Time
U.S. Department of Energy Human Genome Program, http://www.ornl.gov/hgmis
Mutations Affect Genes, Proteins, Traits
Genotype – The genetic makeup of an individual(i.e., the genes it has)
Phenotype – The physical manifestation of the genotype(i.e., what it looks like)
Animal Distributions
Closely related organisms found in geographical proximity
Evidence for Evolution
Homology
The spatial and developmental equivalence of traits that may look quite different
Evidence for Evolution
Vestigial Features
Speaks to imperfect “design”. Best explained by the persistence of shared
traits.
Evidence for Evolution
Individuals in a population that are better adapted for a
particular environment, survive and pass their traits on to their offspring
H.E. Hoekstra
How Does Evolution Work?Through a process called “Natural Selection”
Natural SelectionThe Pocket Mouse Example
Natural SelectionThe Pocket Mouse Example
What can we conclude?
The mice that blend in have an advantage over those that stand out.
They survive and reproduce.
What other types of selection are there besides
Natural Selection?
Sexual Selection (Sexual Dimorphism)
Sexual SelectionThe Birds of Paradise Example
Sexual SelectionThe Birds of Paradise Example
What can we conclude?
The birds that stand out have an advantage over those that blend in.
They have more chances to reproduce.
Natural Selection suggests it is
better to blend in…
Sexual Selection suggests it is
better to stand out…
Can you come up with a theory(or theories) to explain this?!?
Are there any other types of selection?
An Example of Evolution in Action…
BM vonHoldt et al. Genome-wide SNP and haplotype analyses reveal a rich history underlying dog domestication Nature 000, 1-5 (2010) doi:10.1038/nature08837
A: It is artificial selection
Q: Is this natural selection?
Conclusion: Several forms of selection lead to
change over time
