BIO Organisms and Ecosystems 1

The Fossil Record

Accumulation of fossils in sedimentary rock layers

Types of fossil Records

Insect in Amber

Mineralized organic Matter

Trace fossils(footprints)

Frozen soil, ice and acid bogs

Age of fossils are determined by what

Radiometric dating

Why is the fossil record an incomplete chronicle of evolution

Few organisms actually got preserved, many fossils were destroyed by geologic processes,

Origin of life Hypothesis

1920s, A.I Oparin and J.B.S. Haldane independently hypothesized that the early atmosphere was a reducing environment

What year and what did Stanley Miller and Harold Urey demonstrate

1953, they demonstrated abiotic synthesis of organic molecules was possible in a reducing atmosphere

Macromolecules

Spontaneous abiotic synthesis of all four RNA monomers

Stromatolites

layered rocks that formed that form when prokaryotes bind thin films of sediment together

When did O2 gradually accumulate in the atmosphere

2.4 to 2.7 billion years ago

Eukaryotes originated by what

endosymbiosis

What is Endosymbiosis

When a prokaryotic cell engulfed a small cell that would evolve into a mitochondrion

Serial endosymbiosis

a hypothesis that mitochondria evolved before plastids through endosymbiotic events

what multicellular eukaryote was found 1.2 billion years ago

Red algae

When does more diverse multicellular organisms start to appear?

600 million years ago