Exam 1 Flashcards
Homologous
Similar features because they come from the same ancestor
Same form but modified for many different functions
Homologous
Analogous
Sharing similarities because environment has selected for those features (convergent evolution)
Many different forms but modified into the same function
Analogous
Adaptive Radiation
a new species that come from an ancestor that colonizes a new area
Gradual Refinement
a structure that has one function but over time it gets better at said function
exaptation
structure meant for a specific function but starts being used for another function
What is a benefit of extinction
habitats become avalible
Evolutionary history of species/group of species; based on similarities physically and molecularly
Phylogeny
What is the taxonomy list
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
What is first on the taxonomy list
Domain
What is second on the taxonomy list
Kingdom
what is third on the taxonomy list
phylum
what is fourth on the taxonomy list
class
what is fifth on the taxonomy list
order
what is sixth on the taxonomy list
family
what is seventh on the taxonomy list
genus
what is the last on the taxonomy list
species
what are the 3 domains
Bacteria, Archaea, and Eukarya
What is a similarity between the domains Bacteria and Archaea
they are made of prokaryotic organisms
What are the categories under eukarya
protis, fungi, plants, animalia
Horizontal Gene Transfer
Genes transferred from one genome to another through viral infection or plasmid exchange
vertical gene transfer
parents having offspring; DNA being copied and making a new one
How old is the earth
4.6 billion years old
When did earth calm down
3.9 billion years ago
How old is the evidence of the first living thing
3.5 billion years ago
When was the colonization of land
500 million years ago
when did homosapien first appear
200,000 years ago
Radiometric dating
a tool used to assess how old something is by measuring the radioactive isotope of carbon 14; if there’s still a lot remaining then its younger
geologic record
sequence and age of fossils in the rock strata
3 eras of the phanerozoic eon
Paleozoic, Mesozoic, Cenozoic
Paleozoic era
Organisms moved onto land
Mesozoic era
dinosours
cenozoic
the present era
permian extinction
marine animals dying off because there was less coast because of Pangea; boundary between paleozoic and mesozoic eras
creaceous extinction
dinosours die except birds
why were organic molecules able to form
there was no oxygen back then
what are the 3 eons
archean, proterozoic, and phanerozoic
what is the first eon
archean
what was the second eon
proterozoic
what is the present eon
phanerozoic
allopatric speciation
populations of the same species that are separated physically/geographically and disrupts geneflow
what is a by product of allopatric speciation
reproductive barriers
sympatric speciation
new speices aries in the same geographic area as parent species
habitat differentiation
same area but not in the same habitat
sexual selection
a mate is picky about another mate
polyploidy
2+ copies of each chromosome; more than one complete set of chromosomes
Hybrid zones
when separated populations of closely related species come back together and mate again
reinforcement
offspring do not do very well and the barrier is reinforced; hybrids are cut out
fusion
offspring do really well and reverse speciation; two species become one again`
stability
offspring does well but the two other species also do well; they stay separated but don’t die off
gradual speciation
slowly become so different that they become different species
punctuated equilibria
rapid speciation (punctuated) then stop changing for a while (equilibria)
isolations cause different natural selection outcomes and different chance events and mutations
allopatric speciation
Speciation
process by which one species splits into 2+
Biological species Concept
when a group of populations are able to interbreed and produce fertile offspring then they are the same species
what is the problems with the Biological species Concept
- some different species can interbreed
- cannot tell if there is reproductive isolation from extinct organisms that we know of from fossils
- does not apply to organisms who reproduce asexually
Morphological species concept
Based off physical similarities and can apply to asexual organisms and fossils
what is the problem with Morphological species concept
is is very vague where the cut off is
Ecological species concept
defines species by ecological role (niche)
Phylogenetic species concept
defines species based on molecular structure and DNA
what is the problem with Phylogenetic species concept
who decides the cut off
What do reproductive barriers do
isolate gene pools, prevent interbreeding
reproductive barrier before the zygote forms
prezygotic
reproductive barrier after the zygote forms
postzygotic
Habitat isolation
prezygotic barrier where they are in the same area but not in the same habitat
temporal isolation
prezygotic barrier where the species breed at different times
behavioral isolation
prezygotic barrier where there is no mate recognition; females don’t recognize the male unless the mating ritual is preformed
mechanical isolation
prezygotic barrier where mating is attempted because sex organs just don’t fit/not compatible
gametic isolation
prezygotic barrier where eggs and sperm are not compatible
reduced hybrid viability
postzygotic barrier where offspring do not survive
reduced hybrid fertility
postzygotic barrier where hybrid is healthy but cannot reproduce and are sterile
hybrid breakdown
postzygotic barrier where the hybrid survives but THEIR offspring is sterile or not surviving
What are the classifications for the hardy-weinberg equilibrium
- no mutations (cannot control)
- random mating
- no gene flow (no migration)
- no genetic drift
- no natural selection
genetic drift
chance situations causing the gene pool to change
bottle neck effect
population is reduced by a lot which results to loss of genetic diversity
Founder effect
- individuals colonize a new habitat
- the new group will represent the new generation
gene flow
- migration
- moving from one population to the next
natural selection
- adaptive (fit the environment the best)
- indicated by how many offspring you have
stabilizing selection
- middle trait is most favorable
- extremes not common
- very skinty curve in the middle
- common in environments that doesn’t really change
directional selection
- one extreme is favorable but the other is not
- happens in changing environments
- shifts the curve to only one side
Disruptive selection
- 2 extremes are favored
- patchy environments
- sometime causes sexual dimorphism
sexual dimorphism
difference physical characteristics between males and females
Intrasexual competition
males fighting with other males for mates
intersexual competition
one gender is picky about picking a mate; more likely to pick the most colorful and flashy one; goal is to pass on offspring; does not matter if they survive as long just reproduce
Diploidy
preserves variation by hiding recessive alleles
Balancing selection
maintains stable of both extremes (disruptive selection)
Heterozygote advantage
have greater reproductive success than homozygotes
frequency-dependent selection
best one to be is the one nobody else is
neutral
no advantage of disadvantage in the trait
3 things for natural selection to occur
- variability in traits
- differential survival and reproduction
- heritable
differential reproduction
some organisms need to do better than others; favoring survival and reproduction of the fittest
gene pool (limiting natural selection)
- if the trait doesn’t exist in the population than the organism cannot have it even if its beneficial. traits must already be existing and getting better
speed of reproduction
slow reproduction in an environment that is quickly changing means the species cannot adapt fast enough to the environment and risk extinction
Homology
similarity in characteristics that come from a common ancestry
vestigial organs
homologous structures that are not used;
reminisce of ancestral features
molecular biology
- comparing DNA and ammino acid between different organisms
- degree of similarity implies degree of similarity
population
group of individuals of the same species living in the same space and time
Evolution
Change in heritable traits in a population over time
Gene pool
all the genes in a population in any one time
Microevolution
the change in relative frequencies of alleles in a gene pool over time
Modern synthesis
using Darwin’s theory in combination with population genetics (applying old concepts to new)
What is the most common mutation
- chromosomal duplication
- the original copy is unaffected while the new copy can be tinkered with
