Processes of
Evolution & Genetics
Part 1
Learning Objectives: Part 1
1. Demonstrate an understanding of the historical context in
which the theory of evolution was originally formed.
2. Demonstrate an understanding of the theory of evolution
and the mechanisms of evolution (especially natural
selection)
1.
Illustrate this understanding through accurate examples
3. Demonstrate an understanding of the mechanisms that
underpin inheritance
1.
2.
Describe the link between meiosis and Mendelian genetics
Explain how Mendelian inheritance patterns can be modified
by linkage & sex chromosomes
What is Evolution?
• Evolution
• __________________
• More specifically:
• _________________________________
• What does this definition imply?
• Populations ___________, not
_____________
• It is __________
• What does this mean?
What is Evolution?
• Evidence that supports the theory of evolution
____________
• ___________
• ________________ ___________
History of Evolutionary Thought
Pre-Darwinian Views
• ___________
• _____________________
• Earth is ___________
• _________________(4th century)
• _________________of organisms from _________
• _____________________ – closer to ________,
greater excellence
History of Evolutionary Thought
• Precursors to the Theory of Evolution
• 5 scholars & their contributions
Scholars
Charles Lyell
Brief Summary of Contribution
‘Principles of Geology’
Uniformitarianism
Georges Curvier
Saw potential of fossils
Catastrophism
‘Father of Taxonomy’
‘An Essay on the Principles of
Population’
Inheritance of Acquired Characteristics
Transformational evolution
Carolus Linnaeus
Thomas Malthus
Jean-Baptiste Lamarck
History of Evolutionary Thought
Charles Lyell (1797-1875)
• __________________
• ___________________
• Natural processes _________________________
________________________________________
• Processes are _________________
• Used to reconstruct ____________________
History of Evolutionary Thought
Georges Cuvier
• _______________
• How does this idea compare to
the concept of stasis?
• __________________
• ___________event(s) explain
• ____________________
• ____________________
• 1796 paper: Mammoth
Remains
History of Evolutionary Thought
Carolus Linnaeus (1707-1778)
• Developed __________________
• Species, genus, class, order, kingdom
• Binomial Nomenclature
• Genus, species
• Example: ___________
History of Evolutionary Thought
Thomas Malthus (1776-1834)
• “An Essay on the Principles of
Population”
• _____________________________
• Inspired Darwin
• ____________________________
______________________________
History of Evolutionary Thought
Jean-Baptiste Lamarck (1744-1829)
• Inheritance of __________________
• ______________________________
• Central idea: When life forms reproduce, _____
______________________________________
• Changed in form over time for _________________
• Now know: Mechanism is _____________
• Offspring _________________________
Development of Natural Selection
Charles Darwin
• Using Mathus’ essay and Lyell’s uniformitarian view,
combined with his own observations on biological
variation and sexual reproduction, _______________
•
•
•
•
_________________
_________________
_________________
_________________
Development of Natural Selection
Charles Darwin
• _______________________
• Natural selection explains _________________
• Shifts in traits in response to ___________________
• Descent ___________________
• Similar traits indicate _________________
• ______________________
• ________________________
• Affects individual’s _____________________________
• Transmitted ___________________________________
Development of Natural Selection
Key Points to Natural Selection
• _________________________
• Traits are ___________________to the next generation
• Over ______________, successful ______________
• Later generations ____________________________
• All species can ____________________________
Development of Natural Selection
Key Points to Natural Selection
• Competition for ___________ (___________)
• Individuals with ________________________
______________________________________
• _________________________________
• Determines whether a _____________________
• ________________________
Development of Natural Selection
____________________acts on
__________ ________, but it is the
_____________ that they are a part of that
actually ___________.
Describing Traits
• Aptation
• Adaptation
• Exaptation
Natural Selection
in Action
Panda’s thumb
• Lamarckian explanation
• ____________________
• Darwinian explanation
• _____________________
• _____________________________
• Ability to ________________________________
• “The panda's "thumb" is not, __________________. It is
constructed from a bone called the radial sesamoid,
normally a small component of the wrist,” (Gould, 1980)
Natural Selection in Action
MENDEL’S DISCOVERIES
Early Thoughts on Heredity
• Ancient Greek Influence
• Predominant belief  characteristic of offspring
resulted from the blending of parental traits
• _______________________________
• How hereditary information was transmitted was
unknown until the late 19th and early 20th century
Mendel’s Experiments
Mendelian Trait: _______________________
Dominance and Recessiveness
• Dominant Trait: governed by an ____________
_____________________
• Dominant alleles can _____________________
• Recessive Trait: a trait ___________________
• What’s an allele?
• _________________________________________
Dominance and Recessiveness
• How to recognize?
• Uppercase letters refer to dominant alleles (i.e. T)
• Lowercase letters refer to recessive alleles (i.e. t)
• These symbols are used to represent the genotype
• Genotype: __________________________
• Phenotype: ____________________________
Mendel’s Experiments
What happened when
Mendel crossed the parent
generations?
• Parent (TT) (tall) x Parent
(tt) (short)
• Resulting F1 generation
• __________
• Genotype: ________
• Phenotype: _______
Mendel’s
Experiments
What happened when
Mendel crossed F1 hybrids?
• Expression that was absent
from F1 reappeared
• Resulting F2 generation:
• Genotype: ____________
• Phenotype: ___________
Terms to Know
• Homozygous: ______________________________
• Example: Parent Generation
• All tall plants were homozygous for the dominant
allele (tall) = TT
• All short plants were homozygous for the recessive
allele (short) = tt
Terms to Know
• Heterozygous: _______________________________
• Example: F1 Generation
• Offspring of F1 generation were Tt  had inherited one
allele from each parent plant
• Possessing two different alleles at the same locus
Mendel’s Principles of Inheritance
1. Principle of Segregation
• Genes ___________ (i.e. RR, or Rr, or rr)
• During _____________________________
• During fertilization, the genes are reunited and
the ______________________________
• Thus, ____________________________
Explanation for Principle #1
Mendel’s Principles of Inheritance
2. Principle of Independent Assortment
• Distribution of _________________________
___________________________________
• ______________________________________
Explanation of Principle #2
Mendelian Inheritance in Humans
• Mendelian traits (or discrete/simple traits)
• Describes a characteristic influenced only at one locus
• Examples:
• 1.
• 2.
• 3.
• 4.
• 5.