ch 11 Evolution Flashcards
what is Evolution?
process where characteristics of a species change thru time
what did Darwin study re: Natural Selection
the Galapagos Finches and their different sizes in beaks
3 Principles of Natural Selection
- characteristics of organisms of INHERITED
- there is COMPETITION of resources
- offspring vary in characteristics and those with “better” ones survive better
what is Descent of Modification
when there is a change in population
when can Nat Sel really occur?
when there is Genetic Variation in the species in a Population
Adaptation
heritable trait that AIDS SURVIVAL AND REPRODUCTION of an organism in the environment
when does Adaptation occur
when theres a.CHANGE in Genetic Variation overtime
Divergent Evolution
two species evolve in DIFFERENT DIRECTIONS but came from Common Ancestor
- ex. dogs and foxes
Convergent Evolution
two species that are DISTANTLY related, but hav structures that make them look similar
- similar phenotypes
- ex. birds and bees wings
Homologous Structures
- comes from Divergent Evo
- structures that came from common ancestor but functions may b DIFF
- ex. arm bone structure of whales and humans r similar but we do not have fins
Analogous Structures
- comes from Convergent Evo
- structures have similar function but from DIFF common ancestro
- birds and bees wings for flight but they arent fully related
Gene Pool
combo of all genes n alleles present in population
Hardy-Weinberg Equilbrium
if there are no changes that happen in a population that affects the Frequency of Alleles, those alleles will stay thruout generatiosn
Mechanism of Evolution: Natural Selection
inherited genes n phenotypes are either ADVANTAGEOUS or NOT
- Advan = BETTER SURVIVAL and BETTER REPRODUCTION
Mechanism of Evolution: Mutations
ULTIMATE SOURCE OF GENETIC VARIATION
- changes in DNA Sequence
- changes are either Advantageous or NOT, those not r removed from pop
Mechanism of Evolution: Genetic Drift
- (no tokyo drif)
- effect of chace, completly random change in allees in population
- mostly occurs in small pop
Founder Effect
- type of Genetic Drift
- portion of population moves to another area and COLONIZES another area
- introduces the new genes there
Bottleneck Drift
- type of Genetic Drift
- a disastor hits and causes lotta the population to disappear - only a few of population exit the neck of bottle
Mechanism of Evolution: Gene Flow
- movement of alleles in and out of a popluatioponj to another area
- ex. brown beetles going into green beetles area
Evidence of Evolution: Fossils
- me
- organic matter existing under ground from long long ago
Evidence of Evolution: Anatomy
- we have Homologous Structures
- shared bone structure humans and whales and bats and birds
- there exists a shared evolutionary past
Vestigial Structures
- evidence of evo
- structures that exist but do not have a function anymore
- ex. human wisdom teeth, tail bones
Evidence of Evolution: Embrology
- similarities in embryo forms supports we similar
Evidence of Evolution: Biography
- distribution of organisms all over globe explain TECHTONIC PLATES MOVED overtime
Evidence of Evolution: BioGEOGRAPHY
- some species only exist in one single area
- ex. maruspials only in Austraila
Endemic Species
- species that lived in isolated areas
- had to find their own ways to evolve cuz theres no gene flow
Evidence of Evolution: Molecular Biology
- all organisms have DNA, a universal genetic code
Evidence of Evolution: Speciation
- shows some interbreeding occured with individuals nad bam genetic variation
Allopatric Speciation: Sympatric Speciation
- parent species in one location and the othjer species in another
