specific: a change over time in the genetic composition of a population; broad: populations change over generations
Explain the role of fossils in rock strata as a window to life in earlier times
Fossils are remains or traces of organisms from the past. Because rocks are in layers, time periods can be divided into such layers, and thus the gradual changes in creatures over time periods can be observed
How would Georges Cuvier have explained the appearance of the record of life shown in rock strata
Catastrophism: each boundary represents a catastrophe that destroyed many of the species at the time.
Gradualism: Earth's geologic features could be explained by gradual mechanisms currently operating in the world
Uniformitarianism: same geological processes are operating today as in the past at the same rate
What is the importance of uniformitarianism?
It implied that the world is much older than was believed at the time.
Use and disuse
Parts of the body that are used extensively become bigger and stronger; those not used would deteriorate
Inheritance of acquired characteristics
Organisms could pass on modifications (from use and disuse) to their offspring
What is considered to be the great importance of Lamarck's ideas?
The importance was that variation was introduced through inheritance
What are adaptations? Give two examples.
Characteristics of organisms that enhance survival. Differing beak variations, color of body (aposematic coloration)
Individuals with certain inherited traits leave more offspring than individuals with other traits
Variations are heritable
Large beaked birds that reproduce with large beaked birds will most likely have large beaks
e. Coli will divide non stop so long as they are moved to allow for more space and waste is removed
This competition for resources; not all offspring survive
Those HIV viruses that are not resistant to particular bacteria die out
What are two inferences that Darwin made?
1) Descent with modification explains life's unity and diversity. 2) Natural selection brings about the match between organisms and their environment
What is the role of 3TC in inhibiting HIV reproduction?
3TC is inserted instead of cytosine which inhibits gene expression because the genetic code cannot be used properly.
What are four evidences for evolution?
Fossil record, homologous structures, analogous structures, vestigial structures
How does the fossil record give evidence for evolution?
Past organisms differ from present day organisms and many species have become extinct
How do homologous structures give evidence for evolution?
They imply a common ancestor from which the organisms evolved
Explain convergent evolution and describe how analogous structures can rise
Independent evolution of similar features in different lineages is convergent evolution. Analogous structures can rise when different organisms from different lineage face similar problems
What is biogeography? How is it affected by continental drift?
Study of the biographic distribution of species. Continental drift makes continents shift which can make it more difficult to analyze biogeography.