4 stage chemical and physical processes on early Earth that may have produced very simple cells:
1) Abiotic synthesis of small organic molecules.
2) Joining of these small molecules in macromolecules.
3) Packaging of molecules into protocells.
4) Origin of self-replicating molecules.
evolutionary change above the species level. examples include the origin of new group of organisms through a series of speciation events and the impact of mass extinctions on the diversity of life and its subsequent recovery.
Macroevolutionary
Earth formed about...
4.6 billion years ago
Two men who conducted lab experiments that showed that the abiotic synthesis of organic molecules in a reducing atmosphere is possible.
Stanley Miller and Harold Urey
an abiotic precursor of a living cell that had a membrane-like structure and that maintained an internal chemistry different from that of its surroundings.
Protocell
The first genetic material was probably ______, not _____.
RNA, not DNA
RNA molecules called ________ have been found to catalyze many different reactions.
Ribozymes
sedimentary rocks are deposited in layers called _______ and are the richest source of fossils.
strata
a method for determining the absolute age of rocks and fossils, based on the half-life of radioactive isotopes.
radiometric-dating
the amount of time it takes for 50% of a sample of radioactive isotope to decay.
half-life
The division of Earth's history into time periods grouped into three eons- Archaean, Proterozoic, and Phanerozoic- and further subdivided into eras, periods and epochs.
geologic record
The _________ encompasses multicellular eukaryotic life.
Phanerozoic
The Phanerozoic is divided into three eras:
1) Paleozoic
2) Mesozoic
3) Cenozoic
The early rise is O2 was likely caused by ancient ________- bacteria capable to perform photosynthesis.
cyanobacteria
The _________ ______ proposes that mitochondria and plastids (chloroplasts and related organelles) were formerly small prokaryotes living within larger host cells.
endosymbiont theory
an ___________ is a cell that lives within a host cell.
endosymbiont
The ____________ __________ refers to the sudden appearance of fossils resembling modern animal phyla in the Cambrian period. (535 to 525 million years ago).
Cambrian explosion
Fungi, plants, and animals began to colonize land about:
500 million years ago
According to the theory of _____ ________, Eath's crust is composed of plates floating on Earth's mantle.
Plate tectonics
Tectonic plates move slowly through the process of:
continental drift
At times, the rate of extinction has increased dramatically and caused a:
mass extinction
(The "Big Five" Mass extinction events)
Ther _________ extinction defines the boundary between the Paleozoic and Mesozoic eras 251 million years ago.
Permian extinction
(The "Big Five" Mass extinction events)
The ________ mass extinction 65.5 million years ago Mesozoic from the Cenozoic. and marks the period of dinosaur extinction.
Cretaceous mass extinction
period of evolutionary change in which groups of organisms form may new species whose adaptations allow them to fill different ecological roles in their communities.
Adaptive radiation