Phylogeny: history of life and paleobiology

tree of life

the phylogenetic tree that includes all organisms

base is a big mess

rampant horizontal gene transfer and endosymbiosis

bacteria

nuclear envelope: A

organelles(membrane): A

peptidoglycan(cell wall): P

membrane lipids: unbranched

RNA polymerase: one kind

initiator amino acids: formyl methionine

archea

nuclear envelope: A

organelles(membrane): A

peptidoglycan(cell wall): A

membrane lipids: branched

RNA polymerase: several

initiator amino acids: methionine

Eukarya

nuclear envelope: P

organelles(membrane): P

peptidoglycan(cell wall): A

membrane lipids: unbranched

RNA polymerase: several

initiator amino acids: methionine

within eukarya

transformation

process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria in the environment

transduction

viruses transfer genes between one cell to another

conjugation

cells form a connection and one cell(donor) transmits genes to another

linkage mapping

Luca

last universal common ancestor

LECA

last eukaryotic common ancestor comes from LACA

LACA

last archaeal common ancestor

RNA world hypothesis

hypothesis that RNA served as the genetic information of early life bc it can act like a protein and DNA

RNA replacement

DNA - less fragile than RNA

Protein - more amino acids than RNA

Uniformitarianism

Catastrophism

Big Five Mass Extinctions

1. End Ordovician

2. Late Devonian

3. End Permian

4. Late Triassic

5. End Cretaceous

End-Permian Mass Extinction

252 mya, largest mass extinction

Estimated 96% of species go extinct

Coincident with formation of the Siberian Traps, a huge domain of lava that may have altered climate

End-Cretaceous extinction

Mass extinction, 65 Mya

caused by impact of an asteriod hitting the earth.

End-Cretaceous extinction evidence

tons of limestone sink holes that map a crater shape in chicxulut

Comet shoemaker smashed into jupiter showing that an impact can happen

Bunch of fossils buried in landslide

Iridium found(only found in outer space)

fish might have been alive during impact due to glass in gills clearly from boreal spring

Ediacaran biota

An early group of macroscopic, soft-bodied, multicellular eukaryotes known from fossils from 635 mya- 535 mya

debated to be common ancestors of today's eukarya

Kimbrella

mollusc like creature that dragged itself by its foot over microbial mats

Scrape marks in fossil

Cambrian Explosion

rapid diversification of most major animal groups marking the start of the Paleozoic era

vicariance biogeography

Distribution of species is a function of geological changes in the earth's history

convection cells in the mantle

- Large-scale thermal convection cells in the mantle may move tectonic plates.

- Convection cells transfer heat in a circular pattern. Hot material rises; cool material sinks.

- Mantle heat probably results from radioactive decay.

convergent boundary

the boundary between tectonic plates that are colliding

one slides under the other creating a trench

divergent boundary

A plate boundary where two plates move away from each other.

transform boundary

A plate boundary where two plates move past each other in opposite directions

Athenosphere

The soft layer of the mantle on which the tectonic plates move

continental crust

The portion of the earth's crust that is less dense than oceanic crust

will float if collides with oceanic crust

oceanic crust

thinner, more dense, younger crust making ocean floor

Precambrian Era

4550 mya - 541 mya

starts at origin of earth some soft creatures existed

Phanerozoic

541 mya

era of visible life "Visible life"

Paleozoic

541 mya - 252 mya

Mesozoic

252 mya - 66 mya

Cenozoic

66 mya - present

Microbial mats and stromabolites

3500 mya

stromabolites photosynthesize and make colonies as a pile of gel like substance

when too much substance forms they make another mat on top forming a tower

Created oxygen

Oxygen revolution

2400 mya

the accumulation of oxygen released by photosynthesizing cyanobacteria beginning

found by iron bands

iron bands

Banded iron formations from oxygen reacting with iron in the ocean and precipitating to sea floor

fossil evidence of eukaryotes

1800 mya

molecular clocks agree with this fossil evidence