Unit Two: Evolution Flashcards
Theory of Acquired Characteristics
Lamarck says a species adapts to their environment and those traits are passed down
Catastrophism
Cuvier says catastrophes caused evolution
Theory of Evolution by Means of Natural Selection was discovered by whom?
Darwin
How did Lyell influence Darwin?
Evidence that the earth is very old
How did Malthus influence Darwin?
Shortage of resources leads to a struggle for survival
How did Wallace influence Darwin?
Proposed similar ideas, so Darwin published “On Origin of Species” in 1859
What influenced Darwin on his theory of natural selection?
Lyell
Malthus
Wallace
Artificial Selection
What is required for natural selection?
Variation
Struggle for survival
Survival of the fittest pass genes to their offspring
Adaptation
Macro evolution
Descent with modification from common ancestry
What is evidence of macro evolution?
Fossil recording Molecular record (genetics) Homology Embryology Vestigial structures Parallel adaptation Biogeography (adaptions to their environment)
Homologous structure
Structures with different functions, but similar structures
Analogous structure
Structures with different structures, but similar functions
Vestigial structure
Structure with no function today, but had a function in the past
Punctuated Equilibrium
Rapid change followed by long periods of stability
Gradualism
Constant gradual change
Micro evolution
Changes in allele frequencies over time within a population
How does micro evolution relate to macro evolution?
Micro evolution leads to macro evolution.
Hardy-Weinberg Equilibrium
Measures allele and genotype frequencies
Allele frequencies equation
p+q=1
Genotype frequencies equation
p^2+2pq+q^2=1
Dominate allele variable
P
Recessive allele variable
Q
Homozygous dominant allele variable
p^2
Heterozygous genotype variable
2pq
Homozygous recessive genotype variable
q^2
What conditions need to met for a population to be in H-W equilibrium?
No mutation No genetic drift No non-random mating No natural selection No artificial selection
Genetic drift
Due to chance or events in a population
Founder effect
Rare alleles enhanced a small population or chance of events
Heterozygote advantage
Maintenance of genetic variation
Directional selection
Favors one extreme
Disruptive selection
Favors two extremes
Stabilizing selection
Favors the average
Species
Organisms that can produce fertile offspring
Niche
An organisms role in its environment
Intergrade
Results from two subspecies breeding
Hybrid
Results from two species breeding
Race
Intermediate stages in evolution
Speciation
Formation of a new species
Allopatric speciation
Two groups separated by a barrier (more common)
Sympatric speciation
Two groups share a homeland
Pre-zygotic mechanisms
Habitat isolation Temporal isolation Behavioral isolation Mechanical isolation Gamete isolation (prevention of gamete fusion)
Post-zygotic mechanisms
Zygote morality
Hybrid sterility
F2 fitness (hybrid is fertile but has reduced fitness)
Divergent Evolution
Species evolve to two new species over time
Convergent evolution
Two species evolve to one species over time
Parallel evolution
Two species evolve parallel to one another over time
