tree of life Flashcards
what is a fossil
preserved remnant/impression of organism that lived in the past
what is stromatolite
layered rock that results from photosynthetic prokaryotes that bind thin films of sediment together
what is the primordial/prebiotic soup
hypotheical set of conditions that led to transition from abiotic–>biotic world
1) abiotic synthesis of monomers
2) polymerization of small molecules into macromolecules
3) packaging of polymers into protocells
4) origin of inheritance through transmission of self-replicating molecules
stanley miller’s experiment
artificiall/spontaneous synthesis or organic matter under conditions mimicking early earth’s atmosphere+lightning
how can polymers of amino acids form spontatneously without enzymes/ribozomes
- precursor molecules
- thermal energy
- catalyst
what is a protocell
droplet with membranes that maintained an internal chem diff from that of its environ.
–> not living organisms (no genetic materials)
(T/F) Natural selection can favour RNA molecules that self-replicate faster
T
what does the tree of life show
shows evolutionary relationship between ALL organisms
–>similarities in morphology, anatomy, genetic sequences used to group
what does the relative/absolute age of fossils inform us about the evolutionary history of organisms
- many fossils belong tog to species that went extinct
- some fossils resemble organisms that still exist today
- organisms can undergo very rapid morphological changes
what is biostratigraphy
determination of RELATIVE age (imprecise)
–> sedimentary rocks
what is radiometric dating
determination of absolute age (precise)
–> magmatic rocks
what is faunal succession
specific veritcal sequence of fossilized flora and fauna that can be identifies over horizontal distances
what are biozones
intervals of geological strata
What make good biomarkers for biostratigraphy
species with specific ecological requirements and lived for short geological period
what are isotopes
elements with same protons, different neturons
–>unstable isotope decays into daughter isotope at constant rate
–> stable isotope remains constant until fossil is discovered
Waht does radiometric dating use
changes in isotope composition of:
- organisms during transition into fossils
- magmatic rocks
what does disconinuity in fossil records show
important geological, ecological, evolutionary events
- changes in climate, species colonization, erosion
what is the cambrian explosion
time when most major animal groups appear in fossil record
changed from soft -> hard shelled organisms
what is the evolution of bilateral symmetry
- anterior sensing organs (nervous system)
- anterior predation appendages (prey capturing, feeding)
- posterior appendages for movement (swimming, crawwling, flying)
what are adaptive radiations
period of evolutionary change in which groups of organisms form new species whose adaptions allow them to fill diff ecological roles in communities
how are geological eras defined
massic changes in abundance/composition of fossil record AKA mass extinction
how many mass extinctions have there been
5
what are mass extinctions followed by
new adaptative radiations and new families/genera
what are the key innovations in the fossil record
- first cells(prokaryotes)
- increase in )2 conc.
- endosymbiosis (eukaryotes)
- sexual reproduction
- multicellularity
- colonization of land
what is LUCA
last universal common ancestor
what isomer do all living organisms use
L optical isomers
what are likely characteristics of LUCA
living near deep-dea vents, anaerobic (no O2), rich CO2, H2
what are the 3 domains of the tree of life
bacteria, archaea, eukarya
what are the characteristics of bacteria
- photosynthetic, aerobe/anaerobe
- highly resistant to harsh conditions
- most studied organism (cloning)
what are the characteristics of archaea
- prokaryotes
- extremophiles
mostly methanogens (use CO2+H2 to produce CH4)
what are extremophiles
live in extreme environmental conditions
what is the source of DNA polymerase for PCR
archaea –> heat resistance
what are the characteristics of eukarya
- cytoskeleton, endomembrane system, nucleus
- gained new metabolic system
- mitochondrion, plastid
how were eukarya evolved
from prokaryotes in archaea branch
what is serial endosymbiosis
prokaryotic cells engulfed by an ancestral archaea cell, but not consumed
what is the colonial hypothesis
colonies form through cooperation of unicellular organisms of the same species
–> cells fail to seperate
–> specialization can occur
what is the sybiosis hypothesis
cells from different species establish a mutually beneficial and long-term association
what is the burgess shale
paleontological site in BC with sediments with large diversity and different lifestyles
