Phanerozoic Life Flashcards
nonliving
Abiotic
evolution of numerous species from a common ancestor.
Adaptive radiation
diversity of living organisms.
Biodiversity
assemblages of organisms.
Biotas
from living organisms
Biotic
selection of organisms based on the relative contribution of an organism to the gene pool of next generation.
Darwinian selection
area available for organisms to occupy. This is partly a physical space, and partly a series of interactions between organisms.
Ecospace
processes of change in living organisms over time
Evolution
also called ecological niche. The sum of an organism’s use of all available environmental resources.
Niche
organisms with similar anatomical characteristics that can, potentially, interbreed.
Species
organisms with similar anatomical characteristics that can, potentially, interbreed.
Species diversity
science of naming and classifyin organisms
Taxonomy
characterized by a mud-grubbing lifestyle
CAMBRIAN FAUNA
with a much larger filter-feeding cohort and more predators.
PALAEOZOIC FAUNA
characterized by an abundance of predators and an increasing tendency to burrow for protection.
MODERN FAUNA
The most important innovation of the Phanerozoic was the migration of organisms on to land during the Palaeozoic
Biological events have also been extremely important in controlling diversity. Three different faunas can be identified through the Phanerozoic
a. Cambrian fauna
b. Palaeozoic fauna
c. Modern fauna
Dominated by trilobites, arthropods, inarticulate brachiopods and hyolithids.
Fauna is predominantly based on mud eating and most animals live on the sediment surface.
Cambrian Fauna
Dominated by corals, crinoids, brachiopods, predatory cephalopods, and by graptolites in deeper water.
This fauna is more tiered than that of Cambrian with organisms living on, and growing above, the sea bed. Reefs and other biotherms become common.
Palaeozoic Fauna
Dominated by bivalves, echinoids, gastropods, and vertebrates.
Burrowing and predation become very common, increasing faunal tiering yet again and keeping diversity high by regulating the abundance of prey species
Modern Fauna
________________occurs when ecospace is empty, and _____________________ occurs when the environment is already stocked with organisms.
Rapid Diversification
slower diversification
is a measure of variety, and it can be assessed at taxonomic level. It could also be applied to individual variation, or even to various in DNA, but variation at this level is not generally used.
Diversity
most significant event in the evolution of life during the Phanerozoic has been the colonization of land
Mass Extinctions
END ORDOVICIAN
END DEVONIAN
END PERMIAN
END TRIASSIC
END CRETACEOUS
