Evolution Exam 1 Flashcards
hierarchy of biological organizations
atom, molecule, macromolecule, organelle cell, tissue, organ, organ system, individual, population, community, ecosystem, biosphere
difference between living and non living organisms
ability to self replicate and metabolize
population
group of individuals of the same species living in the same area
community
groups of different species living in the same area
ecosystem
community and non living components (rocks, water, sand, air, sunlight, heat)
technology alters/manipulates nature
can’t prove/test a hypothesis
theory
a well supported hypothesis
scientific method
- Observation
- Question
- Hypothesis
- Collect data
- Test Hypothesis
6a. If supported, study done
Modern Synthesis
due to the advances of genetics
“To unroll”
change over time of inherited characteristics of a population
Two Scale Evolution
Microevolution: evolution within a singular species population
Macroevolution: evolution of new species
Natural Selection
differential success in the survival and reproduction of different phenotypes resulting from the interaction of organisms with their environment
Hardy Weinburg Principle
- population genetics
- gene pool
- genetic equilibrium: population in which allele frequencies of a gene do not change
- assumptions: large population size, random meeting, no evolution (NO natural selection, genetic drift, gene flow, mutations)
- genetic frequencies: phenotype vs genotypic vs allelic which represents a population in terms of probability
Fitness
the contribution an individual makes to the gene pool of the next generation, relative to the contribution of other individuals in the population
Key
survival of genes/genotypes (not individuals)
why is natural selection important?
Artificial selection
Antibiotic resistance
Mechanisms of Microevolution
- mutation
- genetic drift
- gene flow
- assortative mating
- sexual selection
- kin selection
- inclusive fitness
Mutations
random chemical change in DNA
Two types of mutations:
point mutation - incorrect nucleotide sequence
deletion- incomplete chromosome
Genetic drift
changes in allele frequencies of a small population due to random process
founder effect (location displacement)- a phenomenon occurred and changed the species geological location which gave them new dominance
bottleneck effect- only allows a few individuals through
Gene flow
change in allele frequency/movement of genes from one population to another
- migration
assortative mating
non-random mating
ex. tall people fuck tall people
sexual selection
differential reproductive success based on differential success in obtaining a mating partner
kin selection
selection of genes that increases inclusive fitness of an individual
inclusive fitness
individuals relative genetic contribution to the next generation, made both through itself and through relatives who have reproduced b/c of the individuals assistance
Origin of species
Reproductive isolating mechanisms:
Prezygotic barriers-
- spatial
- extrinsic
- ecological
- intrinsic
- temporal
- behavioral
- mechanical
- gametic
Postzygotic barriers-
- hybrid zygote abnormaility
- hybrid inviability
- hybrid infertility
- absence/sterility of one sex
spatial (geographic) isolation
occurs between populations that are separated by great distances, but it can also take place between populations that inhabit different parts of the same area.
ecological i.m
intrinsic characteristics of species that reduce or prevent successful reproduction with members of other species.
temporal i.m
times when to reproduce (seasons, day/night)
behavioral i.m
different ways to recognize other species with the same attributes
ex. bird calls/songs
mechanical i.m
reproductive structure or a physical incompatibility between reproductive organs of two organisms
gametic i.m
egg/sperm come in contact but don’t bond/fertilize
hybrid zygote abnomality
deformed physically/molecularly, wont survive
hybrid inviability
survives but dies before the point that it can reproduce
hybrid infertility
mule combo of horse and donkey which makes it infertile to produce another offspring of its kind
absence/sterility of one sex
only one sex reproduces which can’t continue lineage
species concept
- biological
- morphological
- species recognition
- genetic species
biological species concept
group of individuals that have the ability to interbreed/produce viable offspring (doesn’t apply to asexuals or fossil species)
morphological species concept
group of individuals sharing physical attributes
species recognition species concept
if other individuals doesn’t recognize species then its another species
genetic species concept
genetic difference between one population from another to make a new species
macroevolution
- phylogeny is the evolution of the history of organisms
- generally geologic time
- series of speciation events (bush not ladder)
- extinct vs extant
types of macroevolution
- divergent evolution
- convergent evolution
- mosaic evolution
divergent evolution
evolution of 2 descendants species from an ancestral species
- cladogenesis where multiple species evolve from one species
- anagenesis where one specie evolves into another specie
- homology is similarity due to common ancestry
convergent evolution
independent acquisition of structural/functional similarities in two or more unrelated species
- homoplasy: similarity due to the uncommon ancestry
mosaic evolution
different adaptive structure evolving at different rates
- “missing-link” fallacy: fossils fill in the gap
- one characteristic evolves at a time
rates of evolution
- phyletic gradualism (charles darwin)
- punctuated equilibrium (with “stasis”; Stephen J Gould): depends on rate of environmental changes
speciation models
- allopatric: is the separation of environment/land which evolves species in each environment into a new/own kind of species (new species forms b/c of geogrpahic change)
- sympatric: within a geographic location a new species evolves while another is already inhabiting that environment (new species forms within another species community)
other processes
- adaptive radiation: emergence of many species within a short time span
-extinction: disappearance of species
types of extinction
- mass extinction: disappearance of many species within a short time
- background extinction: here and there species go extinct (random)
extinctions main cause is humans
evidence of evolution
- fossil records
- comparative morphology of modern organisms: homologous features and vestigial (remanent) features
- comparative embryology: ontogeny (developmental history of an individual) recapitulates phylogeny (Ernest Haeckel)
- biochemical/genetic data: all cells have DNA = all organisms are derived from a common ancestor
Dominances
- single
- incomplete
- co: both traits equally expressed
- sex linked
