change over time by which a modern organism has decended from ancient organisms
evolution
During his travels, _________ made numerous observations and collected evidence that led_______ changes over time
Darwin, life
Darwin observed characteristics of many animals and plants varied noticeably among the different islands of the ____________.
galapagos
Returning home, Darwin developed his hypothesis that these _______ species were once the same species and that they had evolved from the original South American species after becoming _________ on the island
separate, isolated
Hutton and Lyell helped scientists recognize that earth is many millions of years old and the processes that ________ earth in the past are the same processes that operate in the present
changed
________ proposed that by selective use of disuse of organs, organisms aquired or lost certain traits during their lifetime. These traits could then be passed on to their offspring.
Lamarck
Who reasoned that if the human population continued to grow unchecked sooner or later there would be insufficient living space and food for everyone
malthus
differences among individuals of a species
natural variation
selection where traits people wanted were bred for, things they didnt want were bred out
artificial
members of each species compete regularly to obtain food, living space, and other necessities
struggle for existence
the ability of an individual to survive and reproduce in its specific environment is its_________
fitness
any inherited characteristic that increases an organisms chance of survival is an-------
adaptation
over time, natural selection results in changes in the inherited characteristics of a population. these changes _________ a species fitness in its environment.
increase
common descent principle that implies all organisms were all related
descent with modifications
Darwin argued that living things have been evolving on earth for millions of years. Evidence of this process could be found in the fossil record, the __ distribution of living species, homologous structures of living organisms, and __ in early development
geographical, similarities
structures which have different mature forms but develop from the same embryonic tissue
homologous
combined genetic information of all the members of a population
gene pool
the what of an allele is the number of times that allele occurs in a gene pool compared with the number of times other alleles occur
relative frequency
two main sources of genetic variation are _________ and the genetic _______ that results from sexual reproduction
mutations, shuffling
the number of phenotypes produced for a given trait depends on how many ______ control the trait
genes
controlled by a single gene with only 2 alleles, leads to only two distinct phenotypes
single-gene trait
traits controlled by two or more genes
polygenic traits
natural selection on single-gene traits can lead to changes in allele frequency and thus to _________
evolution
Natural selection can affect the distributions of phenotypes in any of three ways name them
when individuals at one end of the curve have higher fitness than individuals in the middle or at the other end __________ selection takes place
directional
when individuals at the center of the curve have higher fitness than individuals at either end of the curve, ___________ selection takes place
stabilizing
when individual at the upper and lower ends of the curve have higher fitness than those near the middle, __________ selection takes place
disruptive
which selection leads to two distinct phenotypes?
disruptive
random change is allele frequency is __________ ________
genetic drift
in small populations that carry a particular allele may leave more descendants that other individuals, just by chance true or false?
true
a situation where allele frequencies change as a result of the migration of a small subgroup of individuals is known as the what effect?
founder
what principle states that allele frequencies in a population will remain constant unless one or more factors cause those frequencies to change ~ p2+2pq+q2=1
Hardy-Weinberg
the situation in which allele frequencies remain constant is called what?
genetic equilibrium
name the five conditions necessary for hardy-Weinberg equilibrium
vary large population, isolated (no migration) mutations dont alter the gene pool, mating is random, all individuals are equal in reproductive success
the formation of new species
speciation
as new species evolve, populations become
reproductively
when the members of two populations can no longer interbreed and produce fertile offspring, what isolation has occurred
reproductive
what isolation occurs when two populations are capable of interbreeding but have differences in courtship rituals or other types of behavior
behavioral
what isolation occurs when two populations are seperated by geographic barriers such as rivers, mountains, or bodies of water
geographical
isolation in which two or more species live in the same habitat but reproduce at different times
5th Grade Science
