Chapters 15 & 16 Test Flashcards
The genetic change in a population over time
Evolution
Thought about species; said all organisms were related in a hierarchy that went from simple to complex organisms
Aristotle
He thought all members of a species were identical, and that means no species changed over time
Aristotle
French naturalist
George Louis Buffon
Said that species could change over time
George Louis Buffon
Said that closely related species could come from the same ancestor
George Louis Buffon
350 BC
Aristotle
1749
George Louis Buffon
1785
James Hutton
The process of erosion and sedimentation that occurred in the past and present
Uniformitarianism
The man who came up with the theory of uniformitarianism
Changes in rock formation of the earth
James Hutton
1798
George Cuvier
Guy came up with the theory of catastrophism
George Cuvier
Opposite of uniformitarianism
Catastrophism
Said there were brief periods of natural disasters that were responsible for most geological changes
George Cuvier
Identified many fossils and developed the Principle of Super Position
George Cuvier
The lower layers of rocks and fossils in them were older than upper layers
Principle of Super Position
1809
Jean Baptiste de Lamarck
French taxonomist
Jean Lamarck
Guy who tried to classify organisms and believed in the inheritance of acquired characteristics
Jean Lamarck
Things that happened after birth could be passed on to offspring
Inheritance of acquired characteristics
Blending theory of inheritance
Jean Lamarck
Offspring would have intermediate traits between father and mother
Blending theory of inheritance
1830
Charles Lyell
Geologist that believed processes were just slow and steady
Charles Lyell
Guy who supported uniformitarianism
Charles Lyell
Wrote a book about gradual process of science “principles of geology”
Charles Lyell
1859
Charles Darwin
Sailed on the HMS Beagle to do his work
Charles Darwin
Went to the Galapagos where he developed most of his theories and studied animals
Charles Darwin
Influenced by Lyell’s book
Charles Darwin
Came up with the theory of natural selection
Charles Darwin
Observed convergent evolution (species have developed similar characteristics because they were exposed to similar environmental conditions, although they are not closely related)
Charles Darwin
He studied Galapagos finches and tortoises
Charles Darwin
Species change over time from their descendants
Descent of modification
Differential reproductive success of individuals with particular genotypes
Natural selection
Natural selection involves ______ reproduction (random mating)
Natural
Book written by Charles Darwin
Origin of Species
Origin of Species was published in _____
1859
The first edition of Origin of Species did not use the word ______
Evolution
Origin of Species is based upon Charles Darwins’s _______________
Voyage on the HMS Beagle
Did his observations in South America and Southeast Asia
Alfred Russel Wallace
Although separate from Darwin, this man came up with the same conclusions as him
Alfred Russel Wallace
Features that provide a selective advantage because they improve an organism’s ability to survive and reproduce
Adaptations
Darwin’s observations
- Organisms that he saw were varied
- Some variations were inherited
- In a population, more organisms were born than survived and reproduced
- Individuals competed for limited resources to survive
Darwin’s inferences
- Within populations, the inherited characteristics of some organisms make them more likely to survive and reproduce
- The environment selects against nonadaptive traits
- Over time, natural selection can change the characteristics of a population and may give rise to a new species
Examples of Darwin’s inferences
Galapagos finches
During the dry season where seeds were larger/tougher, the finches with the ______ and ______ beaks would do better
Shorter and stronger
During the wet season, seeds were smaller, so finches with the ______ and _____ beaks did better
Longer and pointier
Term given that means natural selection, even though it is not very good
Survival of the fittest
Modes of natural selection
Directional
Disruptive
Stabilizing
One extreme phenotype is the fittest
Directional selection
Example of directional selection
Pepper winged moth
Both extreme phenotypes are selected; the intermediate is not
Disruptive selection
Example of disruptive selection
A beach snail
Extreme phenotypes are unfit; intermediate is selected
Stabilizing selection
The most common form of natural selection in stable, unchanging populations
Stabilizing selection
Example of stabilizing selection
Humans at birth weight
Multiple alleles of a gene persist indefinitely in a population
Balanced polymorphism
Why does polymorphism happen?
The heterozygote has some advantage in the population
Examples of balanced polymorphism
Sickle cell disease
Cystic fibrosis
Phenylketonuria
Tay Sachs Disease
Hardy-Weinberg Equilibrium
The frequency of an allele
Hardy-Weinberg Conditions
- The allele frequencies do not change
- Mutations do not occur
- Individuals mate at random
- Individuals do not migrate in or out of the population
- Population is infinitely large
- Natural selection does not occur
Hardy-Weinberg Equations
p + q = 1
p^2 + 2pq + q^2 = 1
How do evolutionary changes occur?
- Mutation
- Nonrandom mating
- Gene flow
- Genetic drift
- Bottleneck effect
A change in the genetic sequence
Mutation
Mutation….
Drives evolution
Natural selection acts on phenotypes
Occurs by chance
Can be detrimental or advantageous
Nonrandom mating that is the ability to distinguish male from female by appearance
Sexual dimorphism
Migration; immigration and emigration
Gene flow
Coming into the population
Immigration
Leaving the population
Emigration
Changes in allele frequencies purely by chance
Genetic drift
Founder Effect
- Occurs when small groups leave their home population and establishes new settlements
- When they leave, their new group only mates with each other
- Rare traits may become prevalent
- Prevalent traits may become rare
Many members of a population die, which causes the loss of genetic diversity that is permanent
Bottleneck effect
