Chapter 9 - How species evolve Flashcards
adaptive potential
the ability for a population to adjust to new environmental selection pressures
advantageous phenotype
a biochemical, physical, or behavioural trait that increases an organism’s fitness in its local environment
allele
an alternate form of a gene
allele frequency
the proportion of certain alleles in a gene pool
allopatric speciation
the geographic separation of a population from a parent population resulting in the formation of a new species
aneuploidy
when a cell or organism varies in the usual amount of chromosomes in its genome by the addition or loss of a chromosome
antigenic drift
small and gradual mutations in the genes encoding for viral surface antigens
antigenic shift
sudden and significant mutations in the genes encoding for viral surface antigens
antimicrobial agent
an agent that kills or slows the growth of microorganisms. Examples include antiseptics, disinfectants, antifungals, antivirals, and antibacterial agents
antimicrobial resistance
the ability of a microorganism to survive exposure to an antimicrobial agent
bacterial conjugation
the process in which bacteria exchange genetic material via direct cell-cell contact
block mutation
a mutation that affects a large chunk of DNA, or an entire gene
bottleneck effect
the reduction in genetic diversity that occurs when a large proportion of a population is removed due to a chance event
competition
interactions between organisms in which both are negatively impacted when vying for the same limited resource. Can exist within or between species
degenerate
a property of the genetic code which means that a single amino acid can be coded for by more than one codon
deleterious
used to describe alleles that have an overall negative effect on individual fitness when expressed
deleterious allele
an allele that has an overall negative effect on individual fitness when expressed
desirable trait
a heritable phenotype that humans select for during selective breeding
disadvantageous allele
an allele that encodes for a biochemical, physical, or behavioural trait that lowers an individual’s fitness in its local environment
ecological niche
the specific environmental conditions and resources or selection pressures within a particular environment
emigration
the movement out of a population
environmental selection
pressure
a factor in the environment (e.g. limited resources, deforestation, changing temperature, predation) that impacts an organism’s ability to survive and reproduce
epidemic
a dramatically increased occurrence of a disease in a particular community at a particular time
evolution
the change in the genetic makeup of a population over successive generations
fertile
the ability to produce offspring
fitness
a measure of how well an organism survives and reproduces in its environment