Please enable JavaScript.
Coggle requires JavaScript to display documents.
Population Genetics and Evolution (Evolution and Origin of Life (Oxygen…
Population Genetics and Evolution
Concepts
Evolution
gradual conversion from one species to another
extremely slow process
thousands of generations
millions of years
Natural Selection
Charles Darwin
Alfred Russel Wallace
Population Genetics
Factors that Cause the Gene Pool to Change
Mutation
small changes should not be ignored
Accidents
meteorite
volcanic eruptions
hailstorms
floods
droughts
avalanche
human construction
Artificial Selection
humans purposely alter alleles in gene pool
selective breeding
plants
animals
ornamental plants
artificial mutation
to discover new alleles that produce desirable phenotypes
Natural Selection
most significant factor causing gene pool change
survival of the fittest
populations must produce more offspring
progeny must differ in alleles
differential survival among individuals with different phenotypes
acts on preexisting alleles
does not cause mutation
#
Factors that are not part of Natural selection
purpose
intention
planning
voluntary decision making
Situations in which Natural Selection Does Not Operate
if individuals of population are genetically the same
if event doesn't kill one's competitors
Multiple Selection Pressures
drought
need for pollinators
cold
insect attacks
dispersement of seeds
ability to reduce nitrogen
producing enough P-protein
can improve fitness
depends on environmental changes
abundance of different alleles within populations
sexual production
G. H. Hardy
G. Weinberg
ratios do not change
crossing over
Rates of Evolution
takes a few generations to see new phenotype
very few mutations outweigh counterparts
#
human introduction of new plant
new alleles is made to be more advantageous
Speciation
#
Phyletic Speciation
species gradually changes
gene flow
movement of allele
rapid
pollen transfer
carry one full haploid genome
seed dispersal
stay close to parent
long-distance dispersal mechanism
wind
floods
stream flow
island rafting
vegetative propagations
small, mobile pieces
genetic recombination
meiosis
crossing over
animal-mediated pollination
birds
insects
Divergent Speciation
one species evolved into a complete new one
Abiological Reproductive Barriers
any physical nonliving feature
that prevents two populations from exchangng genes
two species that cannot reproduce
allopatric
mountain ranges
Biological Reproductive Barriers
biological phenomenon that prevents successful gene flow
color
shape
frangrance
timing of flowering
flowering dates
two reproductive isolated groups
sympatric speciation
Mimulus lewisii
bumblebees
M. cardenalis
hummingbirds
no pollination, no fertilization
prezygotic isolation mechanisms
populations that can no longer interbreed
postzygotic internal isolation barriers
hybrid sterility
hybrid inviability
reproductively isolated
Adaptive Radiation
a new species becomes over short time
a few million years
colonization of newly formed oceanic islands
Hawaiian
Galapagos
founder individuals
founder gene
original gene pool
genetic drift
gene pool rapidly changing
Convergent Evolution
two distinct unrelated species with same phenotypes
somewhatrelated
cacti
evolved from leafy trees in America
modified leaves
euphorbias
leafy trees in Africa
modified shoots
so much change in a polulation
maples in US
orchids
Evolution and Origin of Life
Conditions on Earth Before the Origin of Life
Chemicals present in the Atmosphere
second atomsphere
first atmosphere was lost in space
reducing atmosphere
lack of oxygen
powerful reducing agents
Energy Sources
intense UV rays
gamma rays
heat
kinetic energy
radioactive decay
electricity
lightning
rainstorms
volcanic eruptions
#
Time available for the Origin of Life
no limits
due to free oxygen
ocean
primordial soup
Chemicals Produced Chemosynthetically
S. MIller
all essential molecules formed
amino acids
sugars
lipids
nitrogen bases
Formation of Polymers
required high concentrations of monomers
seaside pools
intense sunlight
cold temperatures
Aggregation and Organization
fatty acids formed in water
random
genetics
natural selection
heredity
aggregates passed on
Early Metabolism
complete heterotrophs
aggregates with synthesizing enzyme
selective advantage
descendants will be more numerous
energy metabolism
glycolysis
photosynthesis
oxidative electron transport
Oxygen
chlorophyll a
photsynthesis
#
allowed the world to rust
kept oxygen levels low
fungi
algae
bacteria
aerobic respiration conditions
oxidizing atmosphere
transformed form dangerous pollutant
Ozone layer
terrestrial life
The Presence of Life
slow gradual transitions
are aggregates alive?
physics of living and nonliving world
chemosynthesis
origin of life from chemical and physical processes
A. Oparin
J. B. S. Haldane
`
the right organic chemimcals
appropreiate energy sources
a lot of time
absence of oxygen
