8/29 notes Flashcards
two kinds of history
- chronicle
- narrative
chronicle history
non-interpretive or non-explanatory history
examples of chronicle history
- fossil record
- phylogenetic trees
- species distribution
- data and patterns
narrative history
interpretive or explanatory history
examples of narrative history
- story of life on earth
- adaptive scenarios
- causes of historical events
- casual statements
explanations of state imply …
that traits have always been
explanations of change require …
an evolutionary chronicle
theory
a system of ideas or statements held as an explanation or account of a group of facts or phenomena
fact
something that has occurred or is actually the case
hypothesis
- a tentative explanation that accounts for a set of facts
- can be tested for further investigation
scientific theory
a coherent body of interconnected statements based on observation, evidence, and experiments that explain a variety of observations and phenomena
is evolution a scientific theory or a fact?
both; scientific theory and fact
examples of a scientific theory
- atomic theory
- evolutionary theory
- heliocentric theory
- theory of gravity
why care about evolution?
- disease and health
- harvesting of wildlife
- food production
- biodiversity
- human origins
- conservation
- discovery
macroevolution
evolution above the species level that focuses on large phenotypic changes or relatively long periods of time
examples of macroevolution
- mass extinction
- adaptive radiations
- chronicle of life on earth
microevolution
evolution below the species level or among closely related species that focuses on the processes that cause evolutionary change over relatively short periods of time
examples of microevolution
- natural selection
- gene movement through populations
- random specific changes
fish like traits in whales (macroevolution)
- flukes generate thrust
- torpedo shaped body
mammal like traits in whales (macroevolution)
- breathe air via blowhole
- young drink milk
- muscles run the length of the body
- tiny bones where the hips should be
1979 Phillip Gingerich discovers Pakicetus atrox
- found in rocks that formed on land
- skull and body emulate dogs more than whales
- bony wall around middle ear has involucrum
- today involucrum is only present in whales
Ambulocetus natans
- aquatic mammal
- rear feet shaped like paddles
- large tail
- long head
- mammalian teeth
- auditory bulla w/ involucrum
- 48 - 50 myr old fossils
transitional form
a species that exhibits traits shared by ancestral and derived groups, especially when the groups are sharply differentiated
example of transitional form
Ambulocetus natans
vestigial trait
- found in the rudimentary state as a result of evolutionary reduction from a a more elaborated, functional state in an ancestor
- usually an adaption in an ancestral taxon that has lost its usefulness
The Whippo Hypothesis
~ 30 fossil species have been found that illustrate a transition from a terrestrial mammal to an aquatic mammal
HIV
a virus that infects cells that are part of the immune system in humans
what does HIV cause?
AIDS
when was HIV first recognized in the US?
1981
how is HIV trasnferred?
- sex
- blood
- breast milk
is HIV a bacteria or virus?
virus
HIV reproduction
- HIV cannot replicate on its own
- uses the hoses cellular machinery
reverse transcriptase as a function of HIV reproduction
transcribes the HIV genome into DNA
integrase as a function of HIV reproduction
splices HIV DNA into the hose genome
protease as a function of HIV reproduction
cleaves precursor proteins to make functional forms
why is developing drugs to treat HIV difficult?
- their is little that is specific to HIV
- disrupting the HIV lifecycle requires the hosts cells to be disrupted
which immune system cells does HIV infect?
- T helper cells
- marcophages
- dendritic cells
what causes the immune system to become compromised when infected with HIV?
CD4 T cells numbers decline below a critical level
HIV evolution
evolution by natural selection within a host
what type of population size is ideal for HIV?
- huge population size
- high mutation rate
- short generation time
- strong natural selection
solution to HIV
drug cocktails
two life examples of microevolution
- evolution of COVID-19 variants
- evolutions of herbicide resistance in plants
teleology
the doctrine of final causes that natural and historical processes are determined by their ultimate purpose
