Ch. 14 Macroevolution Flashcards
Macroevolution
Evolution above the species level
- changes in organisms which are significant enough that the newer organisms would be considered an entirely new species
For biologists, there is no relevant difference between Macroevolution and microevolution
Both happen in same way for the same reasons
When opponents to evolutionary theory use the terms it’s for ontological reasons
Trying to describe two fundamentally different processes
Biogeography
Study of geographical patterns of diversity
- multidisciplinary field that explores the roles of geography and history in explaining the distribution of species
Adaptive radiation
An event in which a lineage rapidly diversifies, with the newly formed lineages evolving different adaptations
The evolution of a key adaptation
An adaptation that allows the organism to evolve to exploit a new niche or resource
Release from competition/vacated niches
Lineages that invade islands may give rise to adaptive radiations because the invaders are free from competition with other species
Specialization
May subdivide a single niche into many new niches
Rapid diversification of animals corresponds to major environmental changes
- warming and retreat of glaciers
- oxygenation of ocean
Background extinction
The normal rate of extinction for a taxon or biota
Mass extinction
A statistically significant increase above background extinction rate
How many large mass extinctions?
Five
What can result from climate change?
Mass extinction
Rising carbon dioxide from volcanic activity may have led to ___ extinction
Permian
K-T boundary extinction may have been cause by what?
Asteroid impact
