Unit 7: Evolution

• Evolution is the change over time and the process in which modern organisms have descended from ancient organisms.
• Artificial selection is the selective breeding of plants and animals to promote the occurrence of desirable traits in offspring.
• Natural selection is the process where organisms that are suited to their environment survive and successfully reproduce.
• Adaptation is a heritable characteristic that increases an organism's ability to survive and reproduce in an environment.
• Fitness is how well an organism can survive and reproduce in its environment.
• A fossil is a preserved remain or trace of an ancient organism.
• Radiometric dating is a method for determining that age of a sample from the amount of a radioactive isotope to the non radioactive isotope of the same element in a sample.
• Biogeography is the study of the past and present distribution of organisms.
• A homologous structure has similar structures but different functions.
• A vestigial structure is the structure that is inherited from ancestors but has lost much or all of its original function.
• An analogous structure consists of body parts that share a similar function, but a different structure.
• Microevolution is a change in gene frequency within a population.
• Gene pool consists of all of the genes, including all of the different alleles for each gene, that are all present in a population at any given time.
• Allele frequency is the number of times that an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene.
• Genetic drift is the random change in allele frequency caused by a series of chance occurrences that cause an allele to become more or less common in a population.
• Gene flow is the movement of genes into or out of a population.
• Hardy-Weinberg equilibrium is a principle that states that allele frequencies in a population remain constant unless one or more factors cause those frequencies to change.
• Sexual selection is when individuals select mates based on heritable traits.
• Speciation is the formation of a new species.
• Reproductive isolation is a separation of a species or population so that they no longer interbreed and evolve into two separate species.
• Macroevolution is the changes in anatomy, phylogeny, and behavior that take place in clades larger than a single species.
• Extinction refers to species that has died out and has no living members.
• A species is a group of similar organisms that can breed and produce fertile offspring.
• Phylogeny is the study of evolutionary relationships among organisms.
• A clade is an evolutionary branch of a cladogram that includes a single ancestor and all its descendants.
• A cladogram is a diagram that depicts patterns of shared characteristics among species.
• A punctuated equilibrium is a pattern of evolution in which long stable periods are interrupted by brief periods of more rapid change.
• Adaptive radiation is a process by which a single species or a small group of species evolves into several different forms that live in different ways.
• Convergent evolution is the process by which an unrelatted organisms independently evolve similarities when adapting to similar environments.
• Endosymbiosis is a theory that proposes that eukaryotic cells formed from a symbiotic relationship among several different prokaryotic cells (mitochondria and chloroplasts).
• Evolution


  The genetic change in a population of organisms over time.
• Lamarck


  Scientist who proposed that evolution resulted from the inheritance of acquired characteristics.
• Darwin


  Scientist who formulated the theory of evolution by natural selection.
• Acquired traits


  Skills, characteristics, etc. that you obtain during your lifetime. These traits cannot be passed to offspring.
• Inherited traits


  Traits that come from DNA and are passed from parent to offspring.
• Descent with modification


  Principle that each living species has descended, with changes, from other species over time.
• Fossil record


  Preserved remains that provide evidence of ancient ancestors.
• Embryology


  The study of embryos. Can be used as evidence to show that organisms are related and share a common ancestor.
• Biochemistry


  Study of DNA, amino acids, & protein chains. Can be used as evidence to show that organisms are related and share a common ancestor.
• Vestigial structures


  Structures or organs that are often unused, but had a function in an early ancestor.