Cumulative Info (w/ Unit 4) Flashcards
what is special creation?
species don’t change and are separately created
lineages don’t split
earth is young
what is descent with modification?
species change overtime
lineages split and diverge
new life comes from older forms
earth is old
what is microevolution?
changes in species
what are vestigial traits?
important in ancestors but now serves no purpose
what is the biological species concept?
if individuals interbreed and don’t produce offspring, they are SEPARATE species
when did Darwin publish “on the origin of species”?
1859
what are the four stages of evolution?
- variation among individuals
- division into distinct groups
- distinct population with little inbreeding
- irreversible reproductive isolation
what is macroevolution?
major changes that create new form from an older form
what are transitional forms?
in between organism of a species being evolved
EX: dinosaur —archaeopteryx–> modern bird
what developed first, feathers or flight?
feathers
what is homology?
the study of likeness
-human arm, mole paw, horse leg, dolphin fin, bat wing
what are nested sets?
they are used to determine what species share and use common traits b/w them
what is natural selection?
traits that promote survival and reproduction are passed to the next generation
-not always those most fit survive
-NOT goal-oriented
does natural selection work on phenotypes or genotypes? is natural selection perfect?
phenotypes
-they produce imperfect adaptations that are reflexed in a population
what is the process of natural selection?
- variation exists
- variation is heritable
- not all reproduce
- some reproduce more
what are the natural selection tenets? (modern synthesis - combining molecular science and natural selection)
- individuals exhibit variation due to mutations
- the variation is passed down to offspring
- some are more successful at surviving and reproducing
- the most successful have variation that are best adapted to their environment
what is adaptation?
traits that increase fitness relative to those that lack
what are exaptations?
adaptive traits that initially had a different function but now are used in a new way
-panda’s wrist bone shifted into acting as ‘thumb’
what is artificial selection?
-works similar to natural selection except it produces varieties less likely favored in nature
-EX: GMO’s of tomatoes
what is a phylogenetic tree? (1837)
hypothesis of the history of divergence and evolutionary change
-single species and its several descendants
-based on DNA
REFER TO DRAWING IN NOTEBOOK FOR TREE TERMS
what is a polytomy?
simultaneous divergence of taxa
-3-way split due to uncertainty and insufficient data
what are synapomorphies?
derived characteristics shared by 2+ species
what is an apomorphy?
a new derived character that appears in a tree, “separate from”
-NOT GOOD
what is a plesiomorphy?
pre-exisiting ancestral character, “near from”
-a trait in an ancestor that disappeared, but came back again later in the tree
-NOT GOOD
what are three types of groups in phylogenetics?
-monophyletic
-paraphyly
-polyphyly
what is a monphyletic clade?
ancestor and all it’s descendants
what is a paraphyly?
ancestor and some (not all) its descendants
what is a polyphyly?
some of the descendants, NOT the ancestor
what is convergent evolution?
independent appearance of a trait in different lineages
-NOT GOOD
what is a reversal?
loss of a trait in a lineage that later returns
-NOT GOOD
what is homoplasy? what creates it?
shared trait b/w species that did not come from a common ancestor
-created by convergent evolution and reversals
-comparing apples to oranges
-NOT GOOD
what does each nucleotide represent when talking about phylogenetics?
a character/trait
-must be aligned at the right character when comparing two DNA sequences
what is parsimony analysis?
simplest tree is right (KISS)
what does outgroup analysis and parsimony analysis help solve?
convergent evolution
what does outgroup analysis and parsimony analysis help solve?
convergent evolution
what does outgroup analysis and parsimony analysis help solve?
convergent evolution
what is likelihood analysis?
calculates genetic differences and produces a %
what is bootstrapping?
makes artificial data sets and gives a level of uncertainty
what is bayesian inference?
determines probability of data and tree
what is phylogeography?
comparing DNA of species in different locations
-links them to a common ancestor
-use a molecule clock to determine the time in history of speciation
what is a transversion?
purine to pyrimidine
A->C
what is a transition?
purine to purine
A->G
pyrimidine to pyrimidine
T->C
what are three types of variation?
genetic variation
environmental variation
genotype-by-environment interaction
what is genetic variation?
differences due to genes
what is environmental variation?
differences due to external factors (location, weather)
what is genotype-by-environment interaction?
differences in DNA that makes them more sensitive to environmental factors
-EX: sun burn due to pale skin
organisms alter their ___ in response to a ____ in the environment
expression changes (are/are not) heritable
proteins, change
expression changes are NOT heritable
what are epigenetic markers?
altering phenotype by changing gene expression
-chemical modifications