Exam 1 Flashcards
Tree of life
branching, tree-like structure !
representing the evolutionary divergence !
of all living creatures
Why study tree of life?
- one main goal of modern science
- largest framework for studying evolution
- can make our lives better
- name and characterize the living world
Taxon
a group of organisms that is or could be named
Systematics
the study of the diversity of organisms and the relationships among them
phylogeny
evolutionary relationships among species and higher groups of species
taxonomy
the theory and practice of classifying organisms
evolutionary tree
a branching diagram that portrays ancestor-descendent relationships over actual time
cladogram
branching diagram that portrays proximity of evolutionary relationship without explicit temporal dimension
monophyletic group
a group of species that consists of a common ancestor and all of its descendants
paraphyletic group
a group of species that consists of a common ancestor and some but not all of its descendants
polyphyletic group
a group of species whose members do not derive from a single common ancestor within the group
Phylogenetic Systematics
The study of the diversity of organisms based upon their phylogenetic relationships
parsimonius
KISS
importance of taxonomy
- to accurately interpret fossil deposits, it is necessary to strip away the taphonomic overprinting
- important components that promote preservation
taphonomy
the study of the transition of organic remains from the biosphere into the lithosphere
history of an organism/fossil
1 birth 2 growth (ontogeny) 3 mode/ place of death 4 transport 5 post burial history 6 fossil 7 discovery
biostratinomy
perservational/destructional processes occuring between the death of the organism and the final burial in the sediment 1 death 2 transport 3 disarticulation 4 decay
fossil diagenesis
processes during shallow burial 1 burial 2 fossilization 3 exposure 4 collection
actuopaleontology
study of present day post mortem processes to gain insight into taphonomy and other aspects of paleontology
corrasion
state of wear from any or combination of processes:
abrasion - physical process
bio erosion - biological skeletal reduction
dissolution - removal of unstable mineral
lagerstatte
sedimentary deposit with exceptionally good preservation of skeletal and organic remains
concentration Lagerstatten
occurence is remarkable because of abundance of specimens
conservation
preservation of unusual quality
coquina
shell bed
bone bed
bed of bones
condensation deposits
decreased rate of sedimentation
placer deposits
concentration by flow of water
concentration traps
cases and holes
stagnation deposits
decreased microbial decomposition
obrution deposits
transport of organisms to an envirtonment with exceptional preservation
conservation traps
traps with exceptional preservation potential
preservation types
- microbial mats
- carbon clay films
- pyritization
- phosphatization
- silicifiation
modes of preservation
- unaltered
- permineralization
- recrystallization
- replacement
- carbonization
sampling biases
- compositional
- environmental
- temporal
- age classes
- death assemblage
- surveyor
mega-biases
sea level change
climate change
atmosphere and ocean composition
lithostratigraphy
how outcrops and paleoenvironments are related in space and time
stratigraphy
study of layered sedimentary rocks - especially their formation and relationships
facies
body of rock with specified characteristics
lithofacies
consistent lithologic character within a formation
formation
rock unit with identifiable and distinctive lithic characteristics that is mappable on earth’s surface
eon era period epoch age
eon - eonothem era - erathem period - system spoch - series age - stage
walther’s law of correlation
facies that occur in confomable vertical successions of strata also occur in laterally adjacent environments
correlation
process of demonstrating the sorrespondence of geographically separated parts of a geologic unit
biostratigraphy
study of the geometry, biotic composition, and the time relations of fossiliferous rocks
index fossil
taxon that is useful for defining a particular period of time
- rapid evolution
- wide distribution
- independent of sedimentary setting
- distinctive morphology
- high preservation potential
- abundant
biozone
rock defined by fossil content usually representing a particular interval of time
FAD
first appearance datum
LAD
last appearance of datum
total range zone
global stratigraphic ranges of a taxon
teilzone
local stratigraphic ranges of a taxon
concurrent range zone
overlapping taxon range zones of 2 or more taxa
interval zones
interval between two successive FADS or LADs
assemblage zone
3 or more taxa in natural assemblage
abundance zone
when index species reaches a higher level of abundance
Eons
archean > proterozoic > precambrian > phanerozoic
uniformitarianism vs catastrophism
present key to past - past key to present
extinction - mass extinction
speciaton - adaptive radiation
sequence stratigraphy - event stratigraphy
cyclic patterns - episodic patterns
eustasy
change of sea level throughout the world
eustatic changes: tectonism
1st order cycles - 200-400 My - formation/break of continents
2nd order cycles - 10 - 100 My - rates of sea floor spreading
3rd order? - 1 - 10 My - unknown
eustatic changes: glaciation - 4th order cycle
cyclotherms - 20K-400K - form/melt ice sheets
eccentricity - 100K - 400K - change in earth’s orbit around sun
obliquity - 41K - earth’s tilt
precession - 22.5K - wobble of earth’s axis
eustatic changes: thermal expansion
short term
sequence stratigraphy
depositional sequences and processes that produce them
sequence
succession of genetically related strata bounded on top and bottom by unconformities
(paleo)biogeography
study of geographical distribution of (ancient) organisms
- determines climate/environmental factors that influence life
- determines ecology and what other species life comes in contact with
- determines the divergence and speciation of life
vicariance
geographical separation of a population typically by physical barrier resulting in a pair of closely related species
dispersal
tendency of an organism to move away from source area
dispersal routes: corridor
areas with virtually no barriers to dispersal
where organisms can move freely from one spot to
another
dispersal routes: filter bridge
connections that are more selective, i.e.,
not all organisms can move through them successfully
dispersal routes: Sweepstakes Routes
connections that are extremely
tenuous and aren’t normally traversed by organisms
dispersal routes: Noah’s Ark
where the living fauna on a rifted plate is
carried until it docks with another area adding new
components
dispersal routes: Beached Viking Funeral Ships
components incorporated
into the fossil record that are moved by plate tectonics
dispersal routes: Escalator Counterflow and Hopping
related to plate
motion and things either staying in place or island jumping
Simpson Coefficient
C/N x 100 (where C is the # of taxa in
common between two areas and N is the total # of taxa
Jaccard Coefficient
C/(A+B-C) (where C is the number of taxa in
common between two samples and A and B are the numbers of
unique taxa found in each of the two samples)
