Exam 1 Flashcards
process that occurs when genetic variation is lost due to random variation in mating, mortality, fecundity, and inheritance.
Genetic drift
reduction of genetic diversity in a population due to a large reduction in population size (e.g., from loss of food, disaster).
Bottleneck effect
When a small number of individuals leave a large population to colonize a new area and bring with them only a small amount of genetic variation.
Founder effect
the movement of alleles from one population to another, occurs whenever individuals leave one population, join another, and breed
Gene flow
when individuals with intermediate phenotypes have higher survival and reproductive success than those with extreme phenotypes.
Stabilizing selection
when individuals with either extreme phenotype experience higher fitness than individuals with an intermediate phenotype.
Disruptive selection
when individuals with extreme phenotypes experience higher fitness than the average population phenotype.
Directional selection
occurs when the fitness of a phenotype depends on its frequency relative to other phenotypes in a given population.
Frequency dependent selection
evolution of populations; affected by random processes and selection.
Microevolution
Selection in which humans decide which individuals will breed; breeding is done with a preconceived goal for the traits in the population (e.g., dogs, wild mustard).
Artificial selection
phenomenon in which industrial activities cause habitats to become darker due to pollution; individuals possessing darker phenotypes
are favored by selection.
Industrial melanism
The ability of an organism to express different phenotypes depending on the biotic or abiotic environment. Involves regulatory genes that switch on structural genes given the appropriate stimulus
Phenotype plasticity
describes the pattern of phenotypic expression of a single genotype across a range of environmental conditions
Reaction norm
occurs when individuals within a population differ in their ability to attract mates. It favors individuals with heritable traits that enhance their ability to obtain mates.
Sexual selection
the sex which invests the most in producing offspring becomes a limiting resource over which the other sex will compete
Batemans principle
Females may choose mates on the basis of physical characteristics that are indicators of male genetic quality.
Female choice
Males physically competing for access to females, large size, weapons such as claws, antlers, etc. are advantageous in competition
Male-male competition
refers to any trait that differs between males and females of the same species.
Sexual dimorphism
evolution at higher levels of organization including genera, families, orders, and phyla.
Macroevolution
Evolution of new species
Speciation
hypothesized patterns of relatedness among different groups such as populations, species, or genera; depict which groups evolved from other groups.
Phylogenetic tree
the evolution of new species through the process of geographic isolation.
Allopatric speciation
a series of neighboring populations, each of which interbreeds with nearby populations with at least two populations which are unable to interbreed.
Ring species
the evolution of new species without geographic isolation.
Sympatric speciation
species that contains three or more sets of chromosomes; can also give rise to sympatric speciation.
Polyploid
study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life.
Phenology
Seeks to understand how adaptations, or characteristics of an individual’s morphology, physiology, and behavior enable it to survive in an environment.
Individual approach
Examines variation in the number, density, and composition of individuals over time and space.
Population approach
Understands the diversity and interactions of organisms living together in the same place.
Community approach
Describes the storage and transfer of energy and matter.
Ecosystem approach
Examines movements of energy and chemicals over the Earth’s surface.
Biosphere approach
the most fundamental unit of ecology
Individual
individuals that are capable of interbreeding in nature.
Biological species concept
individuals of the same species living and interacting in a particular area.
Population
the extent of land or water within which a population lives.
Geographic range
makeup of a population in terms of age, gender, or genetics.
Demographics
Populations of species living together in a particular area and interacting.
Community
Characteristics of different individuals in a group vary
Variation
Some individuals have characteristics that help them survive and reproduce more successfully than other individuals without those characteristics
Fitness
The individuals with the favorable traits have many offspring that inherit those traits – the traits are then common to the group ()
heritability
phenotypic traits with a current functional role in the life history of an organism that is maintained and evolved by means of
Adaptations
the total amount of carbon fixed by photosynthesis
Gross primary productivity
The amount of carbon fixed after accounting for losses due to respiration is the
net primary productivity (NPP)
is an innate mechanism that controls the physiology or behavior of an organism which changes on a daily, seasonal, yearly, or other regular cycle.
Biological clock
recur at periods less the one day (e.g., feeding forays). Note these occur at predictable intervals; not random.
Ultradian rhythms
the process of lowering the temperature of a liquid or a gas below its freezing point without it becoming a solid.
Supercooling
genetically differentiated strain of a population, each restricted to specific habitats (Turesson 1922). These have a genetic basis, not phenotypic plasticity.
Ecotype
an ecogeographical rule broadly stating that animals adapted to cold climates have thicker limbs and bodily appendages than animals adapted to warm climates. More specifically, it states that the body surface-area-to-volume ratio for homeothermic animals varies with the average temperature of the habitat to which they are adapted
Allen’s rule
physiological term for animals that exhibit characteristics of both poikilothermy and homeothermy. Temporary reduction in set body temperature
Heterothermy
temporary condition resulting in reduction in respiration and loss in power and locomotion)
Torpor
state of reduced metabolic activity adopted by many organisms under conditions of environmental stress. Hibernation is a common form
Dormancy
temporary increase in body temperature by some physiological process.
Facultative endothermy
The rate at which light is attenuated is the
Extinction coefficient
refers to any process through which atmospheric carbon dioxide is converted into a solid compound.
Carbon fixation
The amount of carbon converted by photosynthesis per unit area and time is a measure of
Primary productivity
recur at periods of approximately 24 hours (e.g., activity patterns, nocturnal vs. diurnal, sleep)
Circadian rhythm
recur at periods of approximately one year (e.g., seasonal patterns, migration, reproduction)
Circannual rhythms
(also called epicycles) are cycles of repeated activity occurring at time intervals less than 24 hours
Ultradian rhythm
time between an innate biological activity in successive periods. For flying squirrel activity the time is 24h and 21 minutes.
Free running cycle
synchronization or alignment of the internal biological clock rhythm, including its phase and period, to external time cues, such as the natural dark-light cycle.
Entrainment
Many biological processes are tied to the lunar cycle
Circalunidian
the duration of light or dark that inhibits or promotes a photoperiodic response. Critical daylength varies among organisms but typically is within 10-14 hours.
Critical daylength
are those whose seasonal activity or behavior is stimulated by day length shorter than the critical daylength.
Short day organism
are those whose seasonal activity or behavior is stimulated by day length longer than the critical daylength.
Long day organisms
those whose seasonal activity or behavior is not stimulated by changes in day length. These plants respond to other cues (e.g., temperature, rainfall)
Day neutral organisms
large naturally occurring communities of flora and fauna occupying a major habitat, e.g. rain forest, grassland or tundra.
Biomes
process of solar radiation (light) striking Earth, being converted to infrared radiation (heat), and being absorbed and re-emitted by atmospheric gases.
Greenhouse effect
causes winds moving north or south latitudinally to deflect to the right in the Northern Hemisphere, and deflect to the left in the Southern Hemisphere. This force causes the “trade winds” moving from higher latitudes towards ITCZ to come from northeast direction north of equator (northeast trade winds) and from southeast direction south of equator (southeast trades).
The Coriolis force
the cooling effect of reduced pressure on air as it rises higher in the atmosphere and expands.
Adiabatic cooling
the heating effect of increased pressure on air as it sinks toward the surface of Earth and decreases in volume.
Adiabatic heating
when water vapor is converted back to liquid, water releases energy in the form of heat and warms air.
Latent heat release
the area of greatest insolation where the two Hadley cells converge and cause large amounts of precipitation.
Intertropical convergence zone (ITCZ) or solar equator
