chapter 15 vocabulary
section 1
1. evolution – change over time
2. theory – well supported testable explanation of phenomena that have occurred in the natural world
3. fossil – preserved remains of ancient organisms
section 2
none
section 3
1. natural variation – differences among individuals of a species, found in all species
2. artificial selection – the technique of picking the best, brightest, and abopve all, most profitable of a certain species
3. struggle for existence – the competition of each species to obtain food, living space, and other necessities
4. fitness – ability of an individual to survive and reproduce in its specific environment
5. adaptation – any inherited characteristic that increases an organsim’s chance of survival
6. survival of the fittest – individuals that are better suited to survive in their environment will continue to thrive and reproduce more effectively
7. descent with modification – the tendancy of a living species that decended, with changes, from other species over time.
8. common descent – logically concluded theory that we could find common ancestors for all living things
9. homologous structure – have different mature forms in different organisms but develop from the same embryonic tissues
10. vestigial organ – resemble miniature legs, tails, or other structures
chapter 16
section 1
1. gene pool – the combined genetic information of all the members of a particular population
2. relative frequency – number of times that an allele occurs in a gene pool compared with the number of times other alleles occur
3. single-gene trait – trait controlled by a single trait
4. polygenic trait – trait controlled by 2 or more genes
secntion 2
1. directional selection – when individuals at one end of the curve have higher fitness than individuals in the middle or at the other end
2. stablilizing selection – when individuals near the center of the curve have higher fitness than individuals at either end of the curve
3. disruptive slection – when individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle
4. genetic drift – random change of in allele frequency
5. founder effect – when an allele frequencies change as a result of the migration of a small subgroup of a population
6. Hardy-Weinberg principle – states that allele frequencies in a population will remain constant unless one or more factors cause those frequencies to change
7. genetic equilibrium – situation in which allele frequencies remain constant
section 3
1. speciation – formation of new species
2. reproductive isolation – when the members of two populations cannot interbreed and produce fertile offspring.
3. behavioral isolation – when two populations are capable of interbreeding but have differences in courtship rituals or other types of behavior
4. geographic isolation – two populatio ns are separated by geographic barriers such as rivers, mountains, or bodies of water
5. temporal isolation – two or more species reproduce at different times
