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61 Cards in this Set
- Front
- Back
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Creationism vs. Evolution |
Creationism - •religious view •divine role •intelligent design argument •not scientifically testable Evolution - •evolution from common ancestor •natural selection •scientifically testable |
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What is the "intelligent design" argument? |
"Humans are too complex to have evolved from simple organisms" False. |
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Evolution vs. Natural Selection |
Evolution is the process of change that occurs. Natural selection is the mechanism in which evolution occurs. |
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Catastrophism |
George Cuvier's theory claiming series of catastrophes over time plus a series of creation events
*Reconciles religion and evolution |
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"Inheritance of Acquired Traits" |
Jean Lamarck's theory that the environment influences life and physical traits are passed to offspring Why is this theory flawed? Physically acquired traits cannot be passed to offspring. Traits must be genetically encoded to be passed. |
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True or False Evolution can occur without genetic variation |
False Genetic variation is required for evolution to take place |
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5 Agents of Change |
Genetic Mutation - random changes in genetic code caused by mutagens -ultimate source of new traits -raw material that allows evolution to occur -slow and continuous Natural Selection - mechanism proposed by Darwin that the environment selects certain traits -organisms reproduce more successfully Gene Flow - movement of individuals between populations -traits move to new population Non-random Mating - organisms prefer to mate with certain individuals -selects mates based on preferred attributes (usually visual) Genetic Drift - random variation in the distribution of traits from one generation to the next •Founder Effect - population isolation - small group splits off from main population and creates own population - gene variation is smaller than the original •Bottleneck Effect - catatrophe occurs and kills off vast majority of organisms - limited variation due to gene pool reduction |
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Book by Charles Darwin in 1865 |
On the Origin of Species by Means of Natural Selection |
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Darwin's Fundamental Premises of Natural Selection |
★★★★★★★ •There exists genetically based variation (inheritable) in the traits of a species
•Organisms produce more offspring than can survive
•The environment selects for those organisms with the best adapted traits
•Organisms best adapted to the environment will reproduce most successfully |
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Why do primitive organisms still exist despite evolution? |
If the environment does not change, evolution does not occur because the organism is already well-adapted |
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DNA SNPs |
Single Nucleotide Polymorphisms - very small changes in the DNA sequence that can cause major or subtle change |
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Alleles |
Different forms of a gene ex. Brown eyes/blue eyes |
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Selective Pressure |
Factors that determine the best traits for evolution |
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Adaption |
Trait selected by environment and passed to offspring |
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Selective Pressures |
•Predator-prey interactions (ex. animal evolves camoflauge) •Competiion for resources (ex. giraffe w/longer necks harvest better) •Habitat changes (ex. animal adapts to new climate) |
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True or False Organisms evolve to survive better. |
False This is a teleological statement. Organisms do not evolve by choice. There is no purpose, plan, or intent - natural selection occurs |
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Microevolution vs. Macroevolution |
Microevolution - short-term (how are selective pressures affecting them now?)
Macroevolution - long-term (how are selective pressures causing change over time?) |
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Types of Microevolution |
•Directional Selection - Gradual change in trait (one becomes more prevalent) •Disruptive Selection - One species splits into two (two selective pressures causes speciation) •Stabilizing Selection - Already well-adapted to the environment so traits don't change (usually two selective pressures that stabilize the trait) |
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Artificial Selection |
Humans direct the evolutionary pth to encourage certain traits (ex. dog breeding) |
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Consequences of Artificial Selection |
•Inbreeding •Founder Effect and Bottleneck Effect •Harmful recessive traits •No longer able to survive in wild |
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Limits of Selection |
•Existence of genetic variation •Complex traits involve many genes •Suitable selective pressures •Genes have multiple effects (including dangerous) |
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Uses for Fossils |
•See extint life forms •See similarities in characteristics (transitional forms) •See the stages of evolution |
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Limitations of Fossils |
•Habitat change •Geological disrruption •Soft-bodied organisms |
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Principle of Superposition |
(Relative dating) Older fossils are deeper than newer fossils and certain sediment layers can be used to date fossils |
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Radioisotope Dating |
(Absolute dating) Using the half-life of materials •¹⁴C (~60,000 yrs) •²³⁴U (~80,000 yrs) •⁴ⁿK (~1.3 Billion yrs) |
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Homologous Structures vs. Analogous Structures |
Homogolous - Evolved from common ancestor that had the same trait Analogous - Evolved under the same selective pressures and evoled independently not from the same ancestor |
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Ontongeny Reciprocates Phylogeny |
The development of organism mirrors the evolutionary origins of an organism (earliest stages of life) |
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Vestigial Structures |
Parts of the body that no longer have a function |
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Vestigial Genes |
Genes still present but no longer apparent due to mutation (can still be activated) |
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Poor Examples of "Intelligent Design" |
•Human Pelvis - too small for birth (breech offspring not even naturally possible) •External Testes - too sensitive for the outside, sperm can't survive internal body temperature, important for reproduction •Human Eye - Cones and rods face backwards and a blind spot is created in the very middle of the eye due to the optic nerve •Rubisco Enzyme - Arguably the most important enzyme on Earth, inhibited but oxygen (atmosphere is 0.34% CO2 and 20% O2), photosynthesis is not efficient |
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Amino Acids |
Make up proteins in DNA |
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Molecular Clock |
Changes in DNA sequence used to determine the rate of mutation and when two species diverged from a common ancestor |
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Scientific Binomial |
The most specific name for an organism, no ambiguity Genus species |
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Biological Classification System |
Domain Kingdom Phylum Class Order Family Genus Species |
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Reproductive Isolation |
A group of interbreeding organisms that are reproductively isolated |
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Pre-Zygotic vs. Post-Zygotic |
Pre-zygotic - mating is blocked before fertilization Post-zygotic - mating is blocked fter fertilization |
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Pre-zygotic Reproductive Isolation |
•Ecological - Organisms are separated by a geographical barrier •Mechanical - Reproductive anatomy does not fit together •Temporal - Mating seasons don't align •Behavorial - Mating rituals are different or the organisms are too different in behavior •Gametic Inviability - Gametes (egg + sperm) are incompatible and will not fuse to form a zygote |
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Post-zygotic Reproductive Isolation |
•Hybrid Inviability - embryo/fetus does not develop and is not viable •Hybrid Infertility - Offspring is infertile (ex. horse + donkey = mule but the mule is infertile) |
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Adaptive Radiation |
A special case of disruptive evolution when a species arrives in an area with many open niches and evolve with different selective pressures into different species *Common after major calamities |
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Allopatric Speciation vs. Sympatric Speciation |
Allopatric - Single species that evolves into two species because the population was split by a geographical barrier Sympatric - A sigle species within the same ecosystem is disrupted into the species with no geographical barrier (nonrandom mating) |
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Reinforcement |
When two species mate but create a less-fit hybrid - usually ends up favoring breeding within specific groups |
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2 Ways Speciation can Occur |
Gradualism - Gradual split into two species Punctual Equilibrium - More rapid speciation (more common) |
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Mechanisms of Rapid Speciation |
•Polyploidy
•Mutations to developmental genes
•Geologic time vs "Human" time |
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True or False A single mutation in a gene can lead to major changes and even a new species |
True
One gene may turn on many other genes in a sequence.
An arm may be: Gene = (gene 1 + gene 2 + gene 3...) gene 1= placement gene 2 = bone structure gene 3 = # of fingers on hand |
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Evolutionary Tree vs. Claudistics |
Evolutionary tree - Does not show evolution of single specific characteristic one after another Cladogram - More rigorous and more preferred. Shows the stages in which each characteristic was formed. Each branch is a new trait |
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Clade |
All organisms with "shared derived characteristics" Hair = Tiger Gorilla Human This is a clade |
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The Cambrian Explosion |
Explosion of new life forms (largest adaptive radation - 500mya) |
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Proterozoic |
Era of earliest life |
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Paleozoic |
Era of ocean life (500mya) |
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Mesozoic |
Era of the age of reptiles (250mya) |
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Cenozoic |
Era of humans (65mya) |
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True or False Advance life forms appeared early in Earth's history |
False Advanced life forms are recent additions to Earth in geologic time |
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True or False There are mass extinctions about every 20 million year |
True There have been many mass extinctions *P-T MA was the largest mass extinction about 250mya that wiped out 90% of all life on Earth *K-T MA was the second largest mass extinction about 50mya that was the meteor that ended the age of reptiles |
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Darwin's Fundamental Premises of Natural Selection |
★★★★★★★ •There exists genetically based variation (inheritable) in the traits of a species
•Organisms produce more offspring than can survive
•The environment selects for those organisms with the best adapted traits
•Organisms best adapted to the environment will reproduce most successfully |
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5 Agents of Change |
Genetic Mutation - random changes in genetic code caused by mutagens -ultimate source of new traits -raw material that allows evolution to occur Natural Selection - mechanism proposed by Darwin that the environment selects certain traits Gene Flow - movement of individuals and traits between populations Non-random Mating - organisms prefer to mate with certain individuals Genetic Drift - random variation in the distribution of traits from one generation to the next •Founder Effect - population isolation - small group splits off from main population and creates own population - gene variation is smaller than the original •Bottleneck Effect - catatrophe occurs and kills off vast majority of organisms - limited variation due to gene pool reduction |
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Types of Selective Pressures |
•Predator-prey interactions (ex. animal evolves camoflauge)
•Competition for resources (ex. giraffe w/longer necks harvest better)
•Habitat changes (ex. animal adapts to new climate) |
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Uses for Fossils |
•See extinct life forms •See similarities in characteristics (transitional forms) •See the stages of evolution |
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Poor Examples of "Intelligent Design" |
•Human Pelvis - too small for birth (breech offspring not even naturally possible) •External Testes - too sensitive for the outside, sperm can't survive internal body temperature, important for reproduction •Human Eye - Cones and rods face backwards and a blind spot is created in the very middle of the eye due to the optic nerve •Rubisco Enzyme - Arguably the most important enzyme on Earth, inhibited but oxygen (atmosphere is 0.34% CO2 and 20% O2), photosynthesis is not efficient |
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Catastrophism |
George Cuvier's theory claiming series of catastrophes over time plus a series of creation events
*Reconciles religion and evolution |
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Types of Microevolution |
•Directional Selection - Gradual change in trait (one becomes more prevalent)
•Disruptive Selection - One species splits into two (two selective pressures causes speciation)
•Stabilizing Selection - Already well-adapted to the environment so traits don't change (usually two selective pressures that stabilize the trait) |
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Limitations of Fossils |
•Habitat change •Geological disruption •Soft-bodied organisms |
