phylogenies
the branching patterns of evolutionary relationships
------- Determined by similarity of traits
-Morphological traits (ex: bone measurements, coloring, structures, etc.)
-Behavior
-Genetic similarity
Evolution
a change in the genetic composition of a population over time
Microevolution
evolution below the species level; creating different varieties of a species
ex) grayness of species
Macroevolution
evolution above the species level (created new genera, families, classes or phyla)
ex) finches in galopgos islands: small big beaks, large small beaks
Genes
physical locations on chromosomes within each cell of an organism
Genotypes
complete set of genes in an individual
ex) what makes up blonde hair
Phenotype
actual set of traits expressed in the individual
-->Genetic make-up vs. physical appearance
--> environment plays a role in this
SEA TURTLES
temperature of sand determines gender: male/female
-> sea turtles in cooler climates more likely to be males and hotter temperatures more likely to be females
--> has nothing to do with genes, environment only
-> .5 percent of sea turtles are in florida
three ways evolution can occur
-Evolution by Artificial Selection
-Evolution by Natural Selection
-Evolution by Random Processes
ex) Mutation
ex) Genetic Drift (gene pool changes)
ex) Bottleneck Effect (pop decrease quickly low # of individuals trying to reproduce
ex) Founder Effect (o
Evolution by Artificial Selection
change in genetic composition of a population over time as a result of humans selecting which individuals breed
Evolution by natural selection
the environment determines which individuals survive and reproduce
Round up resistance
ex) sprayed chemicals on farm fields and killed all the pests --organisms that weren't being killed are surviving and reproducing--have more round up resistance organisms than ever before (artificial selection because we created lots of roundup resistance
fitness
ability to survive and reproduce
adaptations
traits that improve an individual's fitness
founder effect
a change in a population descended from a small number of colonizing individuals
Geographic isolation
physical separation of a group of individuals from others of the same species
ex) forest or river
Reproductive isolation
The result of two populations within a species evolving separately so they can no longer interbreed and produce viable offspring
ex) no mating with species
Allopatric Speciation
two populations become distinct species due to a geographic barrier
ex) great wall of china new organisms because of geographic barrier
Sympatric Speciation
two populations become distinct species in the absence of geographic isolation--> in other words created new species without geographic barrier
ex) einkorn wheat and durum wheat mated and through reproduction created common wheat
Four Factors that Affect Adaptations
-Rate of environmental change
-Genetic variation
-Population size
-Generation time
Rate of environmental change
a slowly changing environment gives species more time to adapt to the changes
Genetic variation
less genetic variation means there is less change for the species to adapt to changing conditions
Population size
if a beneficial mutation occurs, it can spread more rapidly in a small population than in a large population-more survival-more reproduction
Generation time
shorter generation time increases the chance that beneficial mutations will occur within a given amount of time and allow them to spread throughout a population faster
(longer generation time harder to adapt)
Range of tolerance
organisms need a certain environment to survive and thrive in
Realized niche
the range of abiotic and biotic conditions under which a species actually lives (this determines population distribution)
Fundamental niche
ideal environmental conditions for a species
Distribution
areas of the world in which a species lives
Generalist
a species that can live under a wide range of living and nonliving conditions --> example is a raccoon eats garbages, animal carcasses, grass lots of things
Specialist
species specialized to live in a specific habitat or to feed on small group of species--> example is a panda bear only eats bamboo
Fossils
remains of organisms that have been preserved in rocks
mass extinction
a large extinction of species in a relatively short period of time --> climate change is accelerated by humans-organisms do not adapt which causes its extinction-humans accelerate changes in environment and organism can't keep up with changes