Evolution B2 Flashcards
Scientific theory
A Model that accounts for non-scientific evidence
Fitness
How well a species is adapted to survive and reproduce in it’s environment
Predation
Increases fitness of predator —> Decreases fitness of prey
Parasitism
Increases fitness of parasite —> decreases fitness of host
Natural selection
-All species produce more offspring than are able to survive
Darwin’s Natural selection point 1: overproduction
when a species has greater offspring = less chance to survive and reproduce as it has many predators
ex: turtles try to get to water after hatching but get eaten
Darwin’s Natural selection point 2: struggle for existence
organisms of the same species(or other) compete for the same limited sources
Darwin’s Natural selection point 3: variation
 no two individuals are exactly alike (except twins)
sexual reproduction creates variability in populations, some traits are random (mutation)
ex.) some individuals in africa are immune to aids (bc of genetics)
Darwin’s Natural selection point 4: survival of the fittest
environment selectd favourable traits. Organisms with advantages survive and reproduce increasing biodiversity
ex. white/black moth = black/white trees from environment
Darwin’s Natural selection point 5: speciation
accumulations of traits over a long period of time
evolution
process of which populations of living things change over a series of generations
fossils
paleontolgy: study of fossils
fossil formation: teeth,shells, bones
mud tracks
poop
relative dating
Determines if fossil is older than one another
absolute dating
Determines the time period of the fossil
biogeography 
Study of variation and geographic distribution of earth
anatomy
Suggests that a organism with similar structures evolved from a common ancestor
homologous
Features with similar structure but different functions, and different uses
analogous
Similar function and appearance but not in origin
Ex. Bird wing and insects wing
vestigial
Feature may have been useful for ancestor but not in current species generation
Convergent evolution
When distantly related organisms evolve similar traits
embryonic development 
Similarity in embryos of different species
biochemistry and dna
All organisms share different dna molecules and some proteins
DNA: hereditary material in cells
Adaptation
Change in organisms characteristic which increases survival chance
Structural adaptation
Physical trait that helps its survive in a environment
Ex. Camouflaging butterfly
Behavioural adaptation
External stimulus a animal does to survive
Ex. Birds migrating
physiological adaptation
A process inside a animals body that helps it survive
Ex. Snake venom
mutation
Random changes in DNA
Environment factors or cell errors
Neutral mutation
No immediate affect in fitness or reproductive success
Ex. Birth mark
Harmful mutation
Reduces individuals fitness
Ex, leukaemia
Beneficial mutation
Gives advantage and most likely will be passed on to offspring
Ex. HIV resistance
sexual reproduction
In plants/ animals
2 copies of each gene
Offspring has combination or random assortment of genes
asexual reproduction
Offspring only has genetic copy of parents dna
speciation
Formation of new species
allopatric
Speciation by reproductive isolation
1. Physical barriers
2. Natural selection
3. Groups no longer sexually compatible
macroevolution
When species rapidly evolve into many species
artificial selection
When humans select and breed individuals with desired traits
Ex. Breeding 2 different dogs
