Define homologous structures
structures that are similar in different species of common ancestry
Define vestigial structures
structure that is inherited from ancestors but has lost much or all of its original function
Define analogous structures
Body parts that share a common function, but not an evolutionary history
Define gene pool
All the genes, including all the different alleles for each gene, that are present in a population at any one time
Define allele frequency
Number of times that an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene
Define directional selection
Form of natural selection in which individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the end of the curve
How does directional selection look on a graph
The curve looks the same but it's shifted to one side
Define stabilizing selection
form of natural selection in which individuals near the center of a distribution curve have higher fitness than individuals at either end of the curve
How does stabilizing selection look on a graph
Middle is very high creates a steel slops
Define disruptive selection
Form of natural selection in which individuals at the upper and lower ends of the curve have high fitness than individuals near the center of the curve
How does disruptive selection look on a graph
The graph dips in the middle and is higher on the sides
Define genetic drift
random change in allele frequency
Define bottleneck effect
A change in allele frequency following a dramatic reduction in the size of a population
Define founder effect
change in allele frequencies as a result of the migration of a small subgroup of a population
Define gene flow
The movement of genes into or out of a population
Define speciation
Formation of new species
Define reproductive isolation
separation of a species or population so that they no longer interbreed and evolve into two separate species
Define behavioral isolation
Form of reproductive isolation in which two populations develop differences in courtship rituals or other behaviors that prevent them from breeding
Give an example of behavioral isolation
the Eastern lark won't respond to Western lark's mating song, vice versa
Define geographical isolation
Form of reproductive isolation in which two populations are separated by geographic barriers leading to the formation of two subspecies
Give an example of geographical isolation
The Gal�pagos Islands are far enough away that the finches don't cross
Define temporal isolation
For of reproductive isolation in which two or more species reproduce at different times
Give an example of temporal isolation
Some flowers don't bloom at the same time so they don't cross-pollinate
Define cladogram
diagram depicting patterns of shared characteristics among species
Define derived character
trait that appears in recent parts of a lineage, but not in its older members
Define relative dating
Method of determining the age of a fossil by comparing its placement with that of fossils in other rock layers
Define index fossil
distinctive fossil used to compare the relative ages of fossils
Define radiometric dating
Method for determining the age of a sample from the amount of a radioactive isotope to the no radioactive isotope of the same element in a sample
Define geologic time scale
Timeline used to represent earths history
Define plate tectonics
Geological processes, such as continental drift, volcanoes, and war, resulting from plate movement
Explain what Charles Darwin contributed to science
Darwin developed a theory of biological evolution that offered a scientific explanation for the unity and adversity of life, by proposing how modern organisms evolved through descent from common ancestors
Explain under what conditions natural selection occurs
Natural selection occurs in any situation in which more individuals are born that can survive, natural heritable variation affects the ability to survive and reproduce, and fitness varies among individuals
Explain what the evolutionary theory suggests about the unity and diversity of life
According to the principle of common dissent, all species -living and extinct- are united by dissent from ancient common ancestors, and exhibit diversity due to natural selection and adaptation
Explain how geographic distribution of species today relates to their evolutionary history
Patterns in the distribution of fossils and living species, combined with information from geology, tell us how modern organisms evolved from their ancestors
Explain how fossils help document descent of modern species
Many recently discovered fossils now show clearly how modern species evolved from extinct ancestors
Identify how homologous structures and similarities in development suggest evolutionary change
Evolutionary theory explains the existence of homologous structures adapted to different purposes as the result of dissent with modification from a common ancestor
Define evolution
Change over time: the process by which modern organsims have desended from ancient organisms
Define fossil
Persevered remains of, or traces of, ancient organisms
Define half-life
Length of time required for half of the radioactive atoms in a sample to decay
Define adaptation
heritable characteristic that increases an organism's ability to survive and reproduce in an environment
Define fitness
how well an organism can survive and reproduce in its environment
Define natural selection
process by which organisms that are most suited to their environment survive and reproduce most successfully; also called survival of the fittest
Explain how the research of the Galapagos finches show natural selection
The grants documented that natural selection takes place in wild Finch populations frequently, and sometimes rapidly
Indentlfy the sources of genetic variation
Genetic variation is produced in three main ways: mutation, genetic recombination during sexual reproduction, and lateral gene transfer
Explain genetic drift
In small populations, individuals that carry a particularly allele may leave more descendants than other individuals, just by chance. Overtime, a series of chance occurrences can cause an allele to become more or less common in a population
Define genetic equilibrium
situation in which allele frequencies in a population remain the same
Explain the conditions that are required to maintain genetic equilibrium
the hardy-Weinberg principle predicts that five conditions can disturb genetic equilibrium and cause evolution to occur
1) non- random mating
2) small population size
3) gene flow from immigration or emigration
4) mutations
5) natural selection
What are the types of isolation that lead to the formation of new species
Reproductive isolation: behavioral, geographical and temporal
Explain the goal of evolutionary classification.
The goal of evolutionary classification is to group species into larger categories that reflect lines of evolutionary dissent, rather than overall similarities and differences
Explain what a cladogram is and know how to interpret them
A cladogram links groups of organisms by showing current hypotheses about how evolutionary lines, or lineages, branched off from common ancestors
Explain how DNA sequences are used in classification
In general, the more derived genetic characters two species share, the more recently they share a common ancestor and the more closely they are related in evolutionary terms
Explain what fossils reveal about ancient life
Fossils reveal information about structures of ancient organisms, the sequential nature of groups in the fossil record, evolution from common ancestors, and the ecology of ancient environments
Explain how we date events in earths history
Relative dating helps paleontologist to determine whether a fossil is older or younger than other fossils radiometric dating uses the proportion of radioactive isotopes to stabilize it hopes to calculate the age of a sample
What are the four principles of natural selection
variation, overproduction, adaptation, descent with modification
Define overproduction
More offspring causes more competition for resources
Define variation
Differences and phenotype within a species
Define descent with modification
Adaptation that increase survival are passed onto the next generation
Describe the difference between artificial selection and natural selection and give an example of both
Artificial selection is selective breeding of plants and animals to promote the occurrence of desirable traits in offspring this is done by humans like when breeding livestock, natural selection is the process by which organisms that are most suited to th
Describe the four evidence of evolution
Molecular (Amino Acid) (how many differences in they're DNA they have, biogeography (where certain species live now and originated, anatomical (similarities and differences in species skeletal structures), and developmental (similarities and differences i
Compare and contrast convergent evolution, divergent evolution and co-evolution
Convergent evolution is a process by which unrelated organisms independently of all the similarities when adapting to similar environments, divergent evolution is when two different selective pressures cause two different species to evolve, and co-evoluti
What selective pressure may have caused the development of calcified eggs?
Animals that lay their eggs on land near hard shells to keep their eggs safe from the elements like sticks and rocks, predators and dehydration