A genetically controlled trait that increases an individual's fitness.
Variations of a given gene.
A situation in which it is beneficial for a population to maintain two different
alleles creating different phenotypes within the population.
Abbreviation for deoxyribonucleic acid, the genetic material of most organisms.
The probability that an individual will contribute its genes to the next
All of the genes of all of the individuals in a population make up a gene pool.
The genetic make-up of an individual. Compare with phenotype.
A situation in which a single disadvantageous allele is not selected out of a
population, because, when a person is heterozygous for that allele (the person
has one disadvantagoues allele and one normal allele), the person gains some
sort of local advantage by having the disadvantageous allele. For example, the
allele for sickle-cell anemia offers resistance to malaria. If a person in an
area high in malaria is heterozygous for sickle-cell anemia, the resistance they
gain to malaria outweighs the disadvantage of having heterozygous sickle-cell
anemia. A person with two sickle-cell anemia cells in such a region is
will not have a greater advantage, even if they are completely resistant to
malaria. What's the use of being resistant to malaria if you're blood can't
The inheritance of different genes independently of each other.
The theory of evolution stating that species change over time and that this
change occurs through use and disuse and the inheritance of acquired
Also called neo-Darwinism and the synthetic theory of evolution, the theory of
evolution that combines Darwinism with information gained from modern
experimental geneticists, population biologists, mathematicians, and
Random changes in the sequence of the DNA in a gene.
The theory holding that competition exists within species, determining which
species live to have offspring and pass their traits on to those offspring.
The traits or characteristics an individual displays. Compare with genotype.
A phenotype that is controlled by more than one gene is said to be polygenic
A group of genetically similar individuals that live in the same area and
The rearrangement of genes on a chromosome that takes place during sexual
The creation of a new species.