Evolution
a common group of genes
How does the fossil record provide evidence for evolution?
shows the change in species over time; organisms in the past were very different from organisms alive today
Define species, using biological species concept.
A group of organisms that can interbreed and produce viable, fertile offspring
Define evolution.
process where populations change over multiple generations, often due to natural selection
Define natural selection.
organisms with traits better suited to their environment survive and reproduce more successfully
What is gene flow?
movement of genes from one population to another as individuals migrate
What are vestigial structures? How are they evidence for evolution?
structures that have lost original function; shows how species evolved from common ancestors
Define speciation.
formation of species as a result of barriers to gene flow that split the gene pool, followed by an accumulation of differences between the gene pools
Compare and contrast microevolution and macroevolution
microevolution: changes within a population due to mutuations, gene flow, genetic drift
macroevolution: changes above the species level, resulting in new species
What does it mean if fitness is increased for organisms?
Their ability to survive and reproduce has improved; organism has traits that make it better adapted or suited to its environment
What is genetic drift?
changes in allele frequencies within a population due to random chance event
DNA sequences can be evidence for evolution. Explain how.
the more similar DNA sequences are, the more closely related the organisms are; they have more recent common ancestor
How does geographic barriers lead to speciation?
populations are isolated and there is no gene flow between groups; no longer able to interbreed successfully
What is the goal or driving factor for any organism?
To survive and reproduce
Peppered moths come in two phenotypes - dark and light. Birds eat the moths that they can see more easily. If the trees where the moths live are dark colored, describe two changes in population that could happen and why?
Light colored moths decrease; easily seen and eaten by predators.
Fill in the blank: ___________ evolve, not ___________
Compare and contrast analogous & homologous structures.
Analogous: different structure, but similar function; similar environmental pressures lead to similar adaptations
Homologous: similar structure, but different function; evolved from common ancestor
Draw an image of speciation over time.
- original population
- geographic barrier
- two new species formed
- unable to reproduce
Describe how mutations are the "raw material" for evolution.
They introduce new alleles or genetic varation into a gene pool; provides the materials for natural selection to act upon
Describe how the rock pocket mice are an example of natural selection.
Fur color adaptation to their environment...areas with light-colored sand, light colored mice blend in more; areas with dark-lava, dark-colored mice are able to camouflage