chapter 25
The broad pattern of evolution above the species level
Macroevolution
What are the four main stages through which simple cells were first produced
1. Abiotic synthesis of small organic molecules (amino acids and nitrogenous basis)
2.joining of small molecules into macromolecules (proteins, nucleic acids)
3. Packing into protocells
4. Self replicating
Droplets with membranes that maintained an internal chemistry different from that of their surroundings
Protocells
What was earths early atmosphere like?
Reducing environment (electron adding)
Why was it unclear if early earth was to be reducing?
Because it wasn't known if there was enough ammonia and methane
What must all organisms be able to carry out?
Reproduction and metabolism
Fluid filled compartments bounded by a membrane like strucutre
Vesicle
RNA catalysts
Ribozymes
Technique for dating the age of fossils based on the decay of radioactive isotopes
Radioactive dating
Time required for 50% of the parent isotope to decay
Half life
What are the first two eons of earths history?
Archean and protozoic
The last half billion years encompassing most of the time that animals have exisisted on earth
Phanerozoic
What are the three subdivisions of the Phanerozoic time period?
Paleozoic, Mesozoic, Cenozoic
Are layered rocks that form when certain prokaryotes bind thin films of sediment togather
Stromatolites
What are some of the more complex organizations that eukaryotes have that prokaryotes don't?
Nuclear envelope, mitochondria, endoplasmic reticulum, cytoskeleton
Posits that mitochondria and plastids were formerly small prokaryotes living within larger cells
endosymbiont theory
Supposes that mitochondria evolved before plastids through a series of endosymbiotic events
Serial endosymbiosis
Many present day animal phyla appear suddenly in fossils formed early in the Cambrian period
Cambrian explosion
What are the 5 big mass extinctions?
Permian, cretaceous,
Periods of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill different ecological roles in their communities
Adaptive radiations
An evolutionary change in the rate or timing of developmental events
heterochrony
If reproductive organ development accelerates compared to other organs, the sexually mature stage of a species may retain body features that were juvenile in ancestral species
paedomorphosis
When a structure that has evolved in one context becomes co-opted for another purpose
Exaptations