Unit 3 - Evolution Flashcards
Evolution
Driven by mutations (aleles, phenotypes) overtime in species
Evolution causes
- Survival of the fit enough to pass on genes
- Creates variation, not all variations become adaptations
Adaptation Types
- Structural (camouflage, mimicry)
- Behavioural (spider web, migration)
- Physiological, systemic response to specific environ (hibernation, venom)
Mutations are
- +, - or neutral based on the environ
- Can occur spontaneously/mutagens (UV rays)
- Only passed on in gametes, if good it becomes selective advantage
Natural Selection
Favoured mutations/adaptations by nature for better survival based on environment causing variation, competition
Sickle-cell anemia
Change in hemoglobin making heterozygous alleles resistant to malaria
Selective Pressures
Biotic (animals) & abiotic (environment)
Artifical Selection
- Doesn’t improve fitness (ability to live & reproduce better)
- Can’t create new alleles
- Can causes health problems/disabilities
- Reduces diversity
Monoculture
Same species of plane, causing lack of variety
Horizontal Gene Transfer
Gaining new allele from diff species
Transitional Fossils
Show organisms w/similarities to 2 groups
Vestigial Structures
Useless structures once used by drive ancestor
Biogeography
Study of how organisms distribute in world
The way similar species spread out
- Location > environ
- Close environ over similar environ
- Close related species never found in same spot
Homologous Structure
Same structure, origin but diff job
Analogous Structure
Same job but diff origin & structure
All living organisms use
- DNA, ATP and same enzymes
- Cytochrome C found in almost all organisms
Gene pool
All alleles frequencies in pop
Gene Flow
Movement of alleles from pop bc of migration
Non-random mating
Mating pattern for particular phenotype/inbreeding (increasing homozygous genotype)
Sexual Selection
- Favouring trait to enhancing mating success
- Causes sexual dismorphism (sex of same species have diff traits)
Mechanism of Evolution
- Mutation in DNA
- Gene flow
- Non-random mating
- Sexual selection
- Genetic Drift
- Natural Selection
Genetic Drift (Mechanism of Evolution)
-Way of changing pop through chance
- Founder effect
- Bottleneck (Fire, Floods)
Hardy-Weinberg Principle
Theory that large pops more likely to have constant allele frequencies over gens
Types of Natural Selection
- Stabilizing selection (average)
- Directional selection (one extreme)
- Disruptive selection (both extremes)
Reproductive Isolation causes
Same species to become distinctly different that they can’t breed w/each other
Types of Speciation
- Formation of new species (macroevolution)
- Sympatric
- Allopatric
- Reproductive
Prevention of Mating
- Behavioural Isolation
- Ecological Isolation (Diff environ)
- Temporal Isolation (TIme, SZN) [BET]
Prevention of Fertilization
- Mechanical Isolation (Diff morphology)
- Gametic Isolation (Sperm doesn’t fuse w/gamete or can’t survive in canal)
Prevention of Hybrids
- Zygotic mortality (Doesn’t develop)
- Hybrid Inviability (Genetic incompability)
- Hybrid Infertility
Hybrid Breakdown
1st Hybrid sucessful but 2nd gen creates weak/sterile offspring
Sympatric Speciation
Evolution of pop into diff speices in same region (from plant change, non rando mating)
Allopatric speciation
- Evolution of population into diff species from region isolation
- Adaptive radiation diversification of common ancestral into diff species (Darwin’s Finches)
Polyploidy from sympatric speciation
- Doubing chromosomes
- Make fertile w/same species, not w/og
Macroevolution & Microevolution
- Large evolution of new species & taxa
- Change in gene frequencies
Abiogenesis
Formation of life from non-living matter
Theory of Gradualism
New species gradually get more distinct
Theory of Punctuated Equilibrium
- Process of evolution is slow
- Sometimes new species evolve quickly in evolutionary times
- Speciation happens in small pop, leaving little transitional fossils
- After initial start, added changes are slow
Divergent Evolution
Differences btwn closely related population within species
Convergent Evolution
Indep evolution of similar features in species of diff period
Parallel Evolution
Same development of trait bc of pressure, not closely related
Founder’s Effect
- Type of allopatric speciation
- Small isolated population start new isolated pop
