Domains

Domain similarities

Eukarya and Archaea: introns and histones

Archaea and Bacteria: no nucleus, circular DNA

all: DNA, cell membrane, proteins, ribosome

hierarchy

domain

kingdom

phylum

class

order

family

genus

species

domain eukarya

plantae, Animalia, fungi, protista

phylogeny

study of relationships between different organisms

• show patterns to show common ancestry (not always based on physical structures)

taxa

group of organisms

order of earth timeline

proto cells

anaerobic respiration

glycolysis

photosynthesis (some oxygen)

aerobic respiration

eukaryotic organisms (spike in oxygen)

multicellular organisms

animals

miller-grey experiment

early earth simulation to show environment (primordial reducing atmosphere)

• electric spark (lightning storm) in chamber with inorganic molecules, provides energy

• water added to boiling chamber to generate heat and flows into electric chamber

• resulted in organic molecules/amino acids (more than 1 carbon)

conserved processes across domains/kingdoms

• glycolysis

• DNA/RNA synthesis

• cell division

• transcription/translation - make proteins

• photosynthesis

cyanobacteria

unique ability of photosynthesis in thylakoid membrane (cyanobacteria, protists, plants)

prokaryotes

no chloroplast

endosymbiosis

how prokaryotes developed into eukaryotes

• membrane unfolds creating nucleus and other membrane bound organelles

• swallows smaller cells (chloroplast and mitochondria)

endosymbiosis evidence

mitochondria and chloroplast

• have own DNA

• double membrane

• used to be ribosomes

binomial nomenclature

genus + species (scientific name)

rate of evolution of DNA sequences

rRNA changes slowly and useful for taxa that diverged a long time ago

mtDNA evolves rapidly and is useful for recent evolutionary events like human evolution

molecular clock

approach for measuring absolute time of evolutionary change based on observation that some genes appear to evolve at constant rates

domain comparison

nuclear envelope: bacteria x archaea x eukarya ✔

membrane enclosed organelles: bacteria x archaea x eukarya ✔

introns: bacteria x archaea ✔ eukarya ✔

histones associated with DNA: bacteria x archaea ✔ eukarya ✔

circular chromosome: bacteria ✔ archaea ✔ eukarya x

extinction from phylogenetic tree

species don’t reach present time

domain with active site

most percentage of homologous amino acids because active site is highly conserved

conservation across domains

glycolysis

photosynthesis

DNA structure/replication

protein synthesis

cytoskeleton

kingdom conservation

membrane bound organelles

linear chromosomes

endomembrane system

evidence for phylogenies

fossils

anatomy/morphology

embryology/development

molecular traits (amino acid sequence in proteins or base sequence in DNA)

behavioral traits

fossils (as evidence)

strengths: determine time, extinct species, transitional

weakness: not all species leave fossils, fossil record incomplete

anatomy/morphology

strength: homologous structures indicate evolutionary relations

weakness: analogous structures do not reflect ancestry

some taxa have little diversity (bacteria)

some morphology reflects environment/diet

embryology/development

strength: reveal similarities in structures not evident in adults

weakness: similarities between species may be lost in later development

molecular traits

strengths: large number of traits, allow study of evolution between closely related species, most accurate

weak: no/little data for extinct species, variation within species blurs differences between species

behavioral traits

strength: some behavior are genetic, ex: frog calls

weak: behavior may be culturally transmitted/learned, ex: bird calls

plesiomorphy

shared primitive/ancestral characteristic, at base of a tree

apomorphy

shared derived characteristic, believed to have evolved within tree so can separate on group in tree from rest

homoplasy

characteristic shared by members but not present in common ancestor (from convergence)

outgroup

group of organisms as reference group for determination of evolutionary relationship among related organisms (comparison group)

fossils

sedimentary rocks, occurs where sediment accumulation is high and organisms with hard parts

rock strata

stacked-up layers of sedimentary rock

cannot determine exact dates, only relativity

radiometric dating

decay of isotopes to determine age of rocks/fossils, based on half life

absolute age

iron oxide bands

evidence of great oxygenation event

adaptive radiation

a rapid increase in the number of species with a common ancestor

new habitats/ecological niches

carbon 14

the more remaining, the younger

alternative hypothesis

shows there is an effect between two things

null hypothesis

no effect