unit 1 evolution Flashcards
what is the proper definition of natural selection
long term reproduction of the fittest in the struggle for existence sometimes leading to progress
can producing sterile offspring increase an individuals fitness?
No the offspring cannot reproduce
what is an abiotic factor
non living factors in an environment
what is intraspecific competition
competition amongst those of the same species for limited resources
selection that favors average phenotypes giving both ends of an extreme a disadvantage
stabilizing selection
selection that favors a phenotype at one end of the spectrum which will change allele frequency
directional selection
favors two or more distinct phenotypes; both extreme ends of phenotypes
diversifying selection
type of selection where environment changes relatively quick and those that can adapt are favored
fluctuating selection
what is a DNA mutation
source for new alleles
type of selection where the success of a trait is deemed by how common or rare it is
frequency dependent selection
if males are rare that means more mating opportunities for males
the vast majority of mutations have a negative or no impact T/F
T
Allele
an aleternate version of a gene responsible for a trait
what does mutation do for changing frequencies
change allele frequencies or creates a new one
what is gene flow
movement of genetic variation from one population to another (orange butterflies going to a yellow population and making more orange)
a random change in allele frequency of a population by chance is
genetic drift ( think of a small population after a catastrophic event)
reduction in population due to a drastic event leading to a smaller population is?
population bottleneck
A small group isolates and starts a new population, eventually those genes in the group become more prominent leading to less genetic diversity is….?
founder effect
what is prezygotic isolation?
what keeps two individuals from mating, like mating dances, mate choice, physical incompatability
what is postzygotic isolation
block successful development of offspring that are hybrids and the success it has reproducing
group of individulas of the same species is a…
population
A unit of DNA that transfers information from parent to offspring determining characteristics is….
gene
what is a gene pool
all genetic information of all individuals in a population
difference in genotype and phenotype
phenotype is whats observed and genotype is the alleles a organism has
during reproduction a new mutation occurs and that gives the offspring a new mutation is this evolution?
yes
change in allele/ trait frequencies is…
evolution
what is plasticity
change in phenotype without change in genotype
what makes attack and flee two different strategies diversifying selection?
these strategies are on two different ends of the spectrum so it
when people think of darwinian selection they usually think of directional selection, why is that?
this is a straightforward example of natural selection and shows how environmental changes will favor an individual at one end of an extreme phenotype leading to a shift in population average.
what is the most common form of selection
stabilizing
best definition of evolution
The process of gradual change in all forms of life over generations through mechanisms such as mutation, natural selection, and genetic drift
is origin of species and natural selection the same
No because origin of species is how a new species comes about and include other factors, natural selection is its own factor
how do populations stop breeding?
Allopatric speciation- geographic separation leading to new species coming about.
Sympatric speciation- species in a certain habitat that have different mating habits, etc that lead to different species emerging
what is sympatric speciation?
group of species in a habitat reproduce and create a new species due to different preferences in mating.
What did lamarck propose for evolution?
a parents experiences are inherited by offspring like a stretched neck of a giraffe
Cuvier helped discover what?
extinction
why was there a slow rise in the discovery of natural selection
religion
lack of knowledge
What did Darwin discover?
Natural selection and popularized evolution
what are homologous structures
features on an organism that share an ancestor
what is convergent evolution
process by which groups of organisms independently evolve into similar forms
what is the term when organisms have the same ability despite not having homologous structures?
analogous structures
what is a vestigal feauture
something that is in an organism that has no use but demonstrates a common ancestor
what do phylogenetic trees do?
we learn how organisms came to be and how they will evolve
on a phylogenetic tree what is the root?
common ancestor for all taxa
what are nodes on the tree
A node is branching point for the phylogenetic tree
what are synapomorphies?
Shared traits/characteristics in a clade
what are symplesiomorphies?
Symplesiomorphies are traits or characteristics that are shared among different groups (clades), but they are not unique to those groups
what is the difference between monophyletic and paraphyletic
monophyletic is a group that includes all the descendants of a common ancestor while paraphyletic only includes some
what is gradualism
gradual change in a population over long spans of time
what is punctuated equilibrium
rate of speciation is not constant this can mean rapid bursts of change and long periods where there is no change
what are the types of viruses
lytic which actively replicate
lysogenic which hid in dna and emerge when drugs stop
how do eukaryotes differ from prokaryotes?
eukaryotes are found in animals, plants, fungi and have membrane bound organelles. Prokaryotes are found in bacteria and archaea and do not have membrane bound organelles. prokaryote
almost all microbes/things in life are prokaryotes…T/F
true to an extent but most life forms we know are eukaryotes
What are the three requirements of natural selection?
Variation of a trait,heritability and difference in fitness
How does speciation and natural selection differ
Natural selection is within a population and favorable traits help survival and speciation in the emergence of a new species not limited to NS
What came before darwin
Scholasticism using education and the bible to explain how god is the reason for things
what is the nested level of classifications of organisms in order from kingdom to species.
Kingdom-broad category like animals, plants, fungi
Phylum-based on body
Class-more specific like mammals, birds
Order-groups that relate like carnivores
Family-groups related like cats, dogs
Genus-closesly relalted species like lions, tigers
Species-most specific like humans, lions
what are the major bacterial groups
csc gab gde
chlamydias
spirochetes
cyanobacteria
gram positive bacteria
alpha proteobacteria
beta proteobacteria
gamma proteobacteria
delta proteobacteria
epsilon proteobacteria
things about
chlamydias
spirochetes
cyanobacteria
chlamydias-parasites of animals
spirochetes- spirals and anaerobic
cyanobacteria- photosynthetic
things about
gram positive bacteria
alpha proteobacteria
beta proteobacteria
gram positive- soil dwelling decomposers
alpha proteobacteria- photosynthetic and mitochondria ancestors
beta proteobacteria- very diverse
things about
gamma proteobacteria
delta proteobacteria
epsilon proteobacteria
gamma proteobacteria-many pathogens
delta proteobacteria- act in iron cycling, nitrogen fixation, work as pathogens
epsilon proteobacteria- many are pathogens
