Chapter 15 Flashcards
Macroevolution
Dramatic biological change: origin of new species, extinction, evolution of major structure
Speciation
Evolution of a new species, may increase biological diversity
Reproductive barriers
Barriers to interbreeding
Adapted radiation
Small group arrives in new habitat, new groups evolve from common ancestors via genetic drift and adaption. Diverse species will adapt to new diverse environments, speciation relies on geographic isolation. Follows founder effect.
Punctuated Equilibrium
Long periods of equilibrium (no change) in fossil record; short spurts of adaptation/speciation (change)
Embryology
Study of organisms development from fertilized eggs to fully formed adults
Geological time scale
Record of earths history. Divided into periods and epochs, divisions
Biological Species Concept
Species = a population/group whose members can interbreed and produce fertile offspring. Distinguish new species, microevolution vs macroevolution
Radiometric dating
Can tell absolute age, presence of radioactive isotope used to date organisms from up to 50,000 years ago. Allows for construction of history of life on earth
Continental Drift
Movement of major land masses due to tectonic plate movement. Organisms separated for a long time are more distinct, and organisms from areas that were recently connected are more similar.
Mass Extinction
When many species are wiped out
Taxonomy
Identification, naming, classifying species
Binomial Nomenclature
2 part scientific naming system
Phylogenetic Tree
Reflects branching evolutionary relationships. Closely related organisms have more homologous structures in common.
Cladistics
Method of grouping organisms based on shared derived traits
Derived Traits
Shared traits inherited from a common ancestor
Analogous structure
Different structures, same functions
Convergent evolution
Species in similar environments evolve similar adaptations
What is the effect of geographic isolation on population of organisms?
They may undergo extensive genetic drift and adaptation, populations may adapt, yet not become a new species
What conditions lead to adaptive radiation?
Small group arrives in a new habitat, new groups evolve from common ancestors via genetic drift and adaptation. Speciation relies on geographic isolation
Why/when would adaptations occur relatively quickly in a population, and what does this have to do with natural selection?
Punctuated equilibrium. Genetic drift, natural selection act quickly (hundreds or thousands of years) on populations adapting to new environment.
Compare gradual adaptation to punctuated equilibrium
Gradual is slowly over time, while punctuated equilibrium has long periods of no change in fossil records, which results in short spurts of adaptation/speciation
What clues can we use to construct a history of life on earth?
The geological time scale and fossils
How might continental drift have contributed to evolution of species?
Organisms separated for a long time are more distinct (independent evolution), and organisms from areas that were recently connected are more similar