Chapter 2 Flashcards
Adaptive radiation
The diversification of an ancestral group of organisms into new forms that are adapted to specific environmental niches.
Adaptations
Changes in physical structure, function, or behavior that allow an organism or species to survive and reproduce in a given environment.
Allele
One or more alternative forms of a gene
Blending inheritance
An outdated, disreputed theory that the phenotype of an offspring was a uniform blend of the parents phenotypes.
Catastrophism
The doctrine asserting that cataclysmic events (such as volcanoes, earthquakes, and floods), rather than evolutionary processes, are responsible for geologic changes throughout earths history
Chromosomes
The strand of DNA found in the nucleus of eukaryotes that contain hundred of thousands of genes.
Demography
The study of a populations features and vital statistics, including birth rate, death rate, population size, and population density
Deoxyribonucleic acid (DNA)
A double stranded molecule that provided the genetic code for an organism, consisting of phosphate, deoxyribose sugar, and four types of nitrogen bases
Dominant
Alleged to an allele that is expressed concern n an organism’s phenotype and that simultaneously masks the effects of another allele, if another one is present.
Endemic
Refers to a characteristic or feature that is natural to a given population or environment.
Evolutionary biology
A specialty within the field of biology; the study of the process of change in organisms.
Evolutionary synthesis
A unified theory of evolution that combines genetics with natural selection.
Fossils
Physical remains of part or all of once living organisms, mostly bones and teeth, that have become mineralized by the replacement of organic with inorganic materials.
Gemmules
As proposed by Darwin, the units of inheritance, supposedly accumulated in the gametes so they could be passed on to offspring
Gene
The basic unit of inheritance; a sequence of dna on a chromosome, coded to produce a specific protein
Gene flow
Admixture, or the exchange of alleles between two populations
Genetic drift
The random change in allele frequency from one generation to the next, with greater effect on small populations.
Genotype
The genetic makeup of an organism; the combination of alleles for a given gene.
Genus
A group of related species
Geology
The study of earths physical history
Habitat
The specific area of the natural environment in which an organism lives
Lamarckism
First proposed by Lamarck, the theory of evolution through the inheritance of acquired characteristics in which an organism can pass on features during its lifetime
Mendelian inheritance
The basic principles associated with the transmission of genetic material, forming the basis of genetics, including the law of segregation and the law of independent assortment
Mutation
A random change in a gene or chromosome, creating s new travi that may be advantageous, deleterious, or neutral in its effects on the organism.
Natural selection
The process by which some organisms, with features that enable them to adapt to the environment, preferentially survive and reproduce, thereby increasing the frequency of those features in the population
Paleontology
The study of extinct life forms through the analysis of fossils.
Phenotype
The physical expression of the genotype; it may be influenced by the environment.
Population genetics
A specialty within a field of genetics; it focused on the changed in gene frequencies and the effects of those changes on adaptation and evolution
Recessive
An allele that is expressed in an organism’s phenotype if two copies are present, but is masked if the dominant allele is present.
Species
A group of related organisms that can interbreed and produce fertile, viable offspring.
Systematics
The study and classification of living organisms to determine their evolutionary relationships with one another.
Taxonomy
The classification of organisms into a system that reflects degree of relatedness.
Uniformitarianism
The theory that processors that occurred in the geologic past are still at work today
