Chapter 18 Flashcards
Two components about scientific theories
Theories are a pattern and a process
Typological thinking
Thinking that all animals come from god and unchanging
Plato- Came up with the idea
Aristotle- Made an heigharchy
Population Thinking
Thinking that populations change change over time due to many factors that affect fitness (Darwin and Wallace)
Paradigm Shfit
A new found information that completley changes how people think about a certain topic
Evidences for evolution
Fossil Records, Geologic Time Scale, Radiometric dating
Stratigraphy
Usignt he position of layers to determine age of fossils
Law of Succesion
Fossils are very familioar to todays species
Transitional Features
Features that are similar in present and ancestors
Vestigial Traits
Traits that are found in present organisms that have no real purpose now
Phylogenic Tree
A diagram that illustrats ancestory
Homology
Similarities between you and past acnestors (3 ways)
Genetic: How similar your genes are to ancestors
Developmental: How similar your embryo development are to ancestors
Structural Homology: How similar your structure are to ancestors
All of these can interact with eachother (Genes determine embryo; embryo determine structure etc.)
Speciation
Process of creating an new species
Internal Consistency
Data from different sources that support a theory
Forces that contribute to natural selection
- populations have varitiy in traits
- Some traits are hertible
- In each generation ore organisms are produced than can survive
- Induviduals with more favorable traits are more likely to survive
Evolution
Change in allel frequencies of a population overtime
Fitness
Ability for an induvidual to duruve to produce viable offsprings
Adaptation vs. Acclimation
An adaptation comes from a heritble trait while acclimation comes from a change in phenotype
Misconceptions about evolutions
-Organisms are not like pokemon and they randomly change during their life
-Acclimation is not and adaptation
-Evolution is goal oriented
-There is no perfect organisms
Argument for alturism in nature
Species with alturistic tendecies do not survive to reproduce offspring and selfish tendencies are rewarded.
Fitness Trade off
A change in trait that affects one aspect of an induviduals fitness, but overall improves the fitness of an organism.
Constraints on natural selection
Non adaptive traits- vestigial and silent mutations
Genetic Constraits- One good trait can negativley affect another trait
Fittness Tradeoffs- u know this one
Historical constraints
What is a species
an evolutionary independent population
Three concepts of indentitfying a species
Biological Species concept: Prezygotic and Postzygotic barriers
Morphological Species Concept: Differences in phenotype
Phylogenic Species Concept: Identifies species based on ancestory
Hangups on all three
Biological: cannot be used for asexual or fossils
Morphological: There are cryptic species and polymorphic species
Phylogenic: There are few well-estimated phylogenic trees
synapomorphies
A shared common trait that is used to distinguish between ancestor and present organisms
Monophyletic group
an ancestral population
plus all of its descendants
Allopatric vs Sympatric speciation
Allopatric is speciation in an isolated region while sympatric was speciation in a shared region
Allopatric types
Dispersal: Population migrates
Variance: Physical splitting of habitat
Sympatric types
External: events from environment speciate organisms (disruptive selection based on niches)
Internal: events from internal environment speciate organisms (chromosomal mutation)
Sympatric by Internal events
Polyploidy: The condition of having a wrong ammount of ploidy
Autopolyploidy: Ploidy change due to mutations
Allopolyploidy: Hybrid offspring has errors in mitosis causing polyploidy
Reinforcement
Traits that pervent/discourage inter-species offsprings
Phaneozoric era
542mya to present
Palezoic
Initial diversification of animals (permain exctintion)
Mesozoic
Gymnosperms and dinosuars
Cenozic
Mammals and angiosperms domintae (persent)
Cambrain explosion
1st animal saround 635 mya
Cambrain explosion
1st animal saround 635 mya ajnd was cuased by high O2 levels, Predation, and many new niches
Permian exctintion
Largest extinction event (90% of all life died)
Cretaceous Extinction
Large meteor destroyed all dinsouars (60-70% of life)
K-T boundary
Associated with the Cretaceous Extinction and It is a layer of sediment that is used to determine if a fossil was before or after the the Cretaceous Extinction
