Macroevolution class one

beginning of genetic replication

you have a protocell that contains self replicating RNA

protocell splits and some of the replicated RNA remiains in both cells

When did life start to begin

3.5 - 3.9 billion years ago

split into 4 eons

what are the 4 eons

1. Hadean eon

2. archean eon

3. proterozic eon

4. phanerozonic eon

what was first to arise

Prokaroytes

Archean eon

Prokaryotes and atmosphere oxyegn formed

Proterozic eon

single celled eukaroyes and multicellar eukaroyes formed

hadean eon

only contains the formation of earth

Phanerozonic eon

colonizartion of land and animals formed

Stromatolites

fossilized groups of photosynthetic prokaryotes

• arranged in layers

• arose in the ocean

Photosynetics prokatoyes increase led to what

more O₂ in the atmosphere, less CO₂

Oxygen levels rapidly rose in the ocean and atmosphere

this was a problem

• Majority of prokaroyes at this time were anearobic meaning oxygen was toxic for them

The great oxidation event

mass extintion when oxygen levels rose

Cellular respiration

When prokaroyes developed the ability to harness the reactive nature of oxygen (from its electronegaivity) to acquire energy from organic molecules

two types of prokaroyes

1. Aerobic prokaryotes

2. Photosynthetic prokaryotes

Endosymbiosis

rise of eukaryotic life

500 years ago

lifeorms were only unicellular → immercenge of mutil cellular eukaroyes from photosynthetic plants (algae)

how did fungi and animals form

Eventually non photosynthetic multicellular eukaroyes would emerge becoming the ancestors to fungi and animals

How long ago was the colonization of land

everything was in the ocean until about 100 million years ago

radiometric dating

utilized radioactive isotopes within fossils to determine thier age

isotopes

diffrent number of neutrons

Half life of an isotope

amount of time it takes for half of the total number of isotopes to decay

carbon dating

measure the age of the fossil by measuring the decay of carbon - 14

potassium dating

measures the decay of potassium-40 (used for older fossils)

Geologic record

used in determining the timeline of life

• In general the deeper a fossil is found in the ground the older it is

Geologic record categories

Broad: eons

Eons → eras

Era → Periods

Periods → Epochs