Natural Selection

observation on natural selection: in each generation, populations produce _____ _______ ______ _____ _____ _____. multiple causes of death

more offspring than there are adults.

observation on natural selection: populations ___ ____ continue to _____ in size

do not; grow

observation on natural selection: food and many other resources are _________

limited

observation on natural selection: ________ within all populations ______ in height colour, speed, etc.

individuals; vary

observation on natural selection: many __________ are _________

variations; heritable

inference on natural selection: _______ within a population ________ for _______

individuals; compete; resources

inference of natural selection: some ________ will _______ _______ that give them an _______. (better chance of surviving and reproducing)

individuals; inherit characteristics; advantage

theory of natural selection: over time, the _______ _______ as ________ _______ characteristics become more common ________ after geeration

population changes; advantageous heritable; generation

adaptation

a characteristic or feature of a species that makes it well suited for survival in the environment

survival of the fittest

fitness is defined by reproductive success. no offspring= not fit. fitness= fit to the environment

differential reproduction

variation in reproductive rates

differential survival

differences in survivability by organisms

selection pressure

factors which determine if an organism is successful at surviving and reproducing

selected for

traits with advantages

selected against

traits with disadvantages

fitness

the ability to survive and reproduce

heritable trait

a characteristic which is influences by genes and passed on from one parent to offspring. (fur coulor on a mouse)

natural selection

over time, an adaptation becomes more and more common in a population.

natural selection and fitness

because the adaptation generally increases fitness, the individuals with the trait generally produce more offspring.

natural selection and heritability

because the trait is heritable, offspring generally have the same trait as their parents. over time this adaptation becomes more and more common in the population

natural selection and environment

a characteristic that is an adaptation in one environment may not be one in another environment