Ch.25 Flashcards
Define ancestral trait
It is a characteristic that existed in an ancestor
Define derived trait
Is one that is a modified form of the ancestral trait found in a descendent That originate via mutation selection and genetic drift
Define Clades and lineages
Clades- are composed of sets of tips that are in existence at one time
Lineage- forms Clades Play relationships detain between ancestors and descendants
Define intact fossil
Is a fossil that is formed when decomposition does not occur and the organic remains are preserved intact
Define compression fossil
It is a fossil that is formed when sediments accumulate on top of the organism and become cemented into rocks due to the pressure
Cast fossil
Is a fossil that is formed when organisms decompose after they are buried
Permineralized fossil
Is a fossil when organisms decompose extremely slowly. dissolved minerals gradually infiltrate the interior of cells and Harden into stone
Trace fossil
Is a fossil that forms when sedimentation and mineralization preserve indirect evidence of an organism in the environment including foot prints tracks, burrows, feeding marks and feces
What are the limitations of the fossil record?
- habitat bias
- Taxonomic and tissue bias
- Temporal bias
- Abundance bias
Define adaptive radiation
Is the rapid production from a single lineage of many descendant species
What triggered the Cambrian explosion?
Higher energy levels
Rise of algae
The evolution of predation
New niches made more new niches
New genes, new bodies
What’s the current extinction rate for the sixth mass extinction
It is 100 or even 1000 times higher than the background extinction rate
What can cause the sixth Mass extinction?
Habitat loss
Invasive species
Pollution
Climate change
Overfishing
