Theory of Natural Selection Guided Notes!
NAME:_______________________
Learning Goals:
1) Define ___________ & ___________ _____________.
2) Describe the 4 steps of Natural Selection, giving an example of each.
3) Explain the importance of _____________.
4) Does Natural Selection act on an organism phenotype or genotype?
5) List the 5 evidences that support the Theory of Evolution.
Theory of Evolution
Evolution: The process of ____________ over ___________.
!
Specifically a change in the ________________ of a gene or allele in a
____________ over time.
Charles Darwin
• Father of _____________.
• Proposed a mechanism for evolution, ____________ ______________.
• Darwin went on a ____ year trip around the world on the ship, the _______ ________.
• Wrote a book, “_________ ____ ________ ____________”
Natural Selection
• Natural Selection: ____________ that are best adapted to an environment ________
and ____________ more than others.
• Darwins Theory of Natural Selection occurs in 4 steps:
• 1) Overproduction
• 2) Variation
• 3) Competition
• 4) Selection
Overproduction
• Each _________ produces more _________ that can survive.
Variation
• Each __________ had a unique combination of inherited traits.
• _______________: an inherited trait that increases an organism’s chance of
survival.
Why is Variation Important?
• Because the environment changes.
• The more _____________ within a species, the more likely it will __________.
!
EX: If everyone is the same, they are all vulnerable to the same environmental
!
changes or diseases.
Theory of Natural Selection Guided Notes!
NAME:_______________________
• The more variation of _________ of _________ in an habitat, the more likely at least
some will ________.
• EX: Dinosaurs replaced by mammals.
Competition
• Individuals __________ for limited resources:
• Food, _________, space, mates
• Natural Selection occurs through “_____________ of the ____________”
• _________: The ability to survive and reproduce
• Not all individuals survive to adulthood.
Selection
• The individuals with the ________ ___________/ adaptations will survive and have
the opportunity to pass on it’s traits to ___________.
• Natural selection acts on the ____________ (physical appearance),not the
___________ (genetic makeup)
• EX: when a predator finds it’s prey, it is due to the prey’s physical characteristics,
like color or slow speed not the alleles (BB, Bb).
• Individuals with traits that are not well suited to their _____________ either die or
leave few offspring.
• Evolution occurs when __________ __________ build up in a population over many
generations and bad traits are eliminated by the ____________ of the individuals.
Descent with Modification
• Descent with Modification- each _____________ species has descended, with
_________ from other species over time.
• ___________ ______________- all living organisms are related to one another.
Evidence for Evolution
• Fossil Record
• __________________ Body Structures
• Vestigial Organs
• Embryology
• ________________ Evidence
Theory of Natural Selection Guided Notes!
NAME:_______________________
The Fossil Record
• ______________: a record of the history of life on Earth
• Archaeopteryx- Missing link between ______________ and birds.
Homologous Body Structures
• Homologous Body Structures: similar _______________ in different types of animals
because of ____________ ancestor.
Vestigial Organs
• Vestigial Organs _____________ traces of evolution that serve no purpose
Embryology
• ________________: embryos of all vertebrates are very ____________ early on.
Biochemical Evidence
• __________________: DNA with more similar sequences suggest species are more
closely related.