Ch. 2 -- Evolution: Constructing A Fundamental Scientific Theory Flashcards
Adaptive radiation
The diversification of an ancestral group of organisms into new forms that are adapted to specific environmental niches
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An outdated, disreputed theory that the phenotype of an offspring was a uniform blend of the parents’ phenotypes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 earthquakes, volcanic eruptions, and floods), rather than evolutionary processes, are responsible for geologic changes throughout Earth’s history
Chromosomes
The strand of DNA found in the nucleus of eukaryotes that contains hundreds or thousands of genes
Demography
The study of population, especially with regard to birth, survival, and death, and the major factors that influence these three key parts of life
Deoxyribonucleic acid (DNA)
A double-stranded molecule that provides the genetic code for an organism, consisting of phosphate, deoxyribose sugar, and four types of nitrogen bases
Dominant
Refers to an allele that is expressed in 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
The study of organisms and their changes
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 in 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 Earth, especially with regard to its composition, activity, and 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 acquired 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 a new trait 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 fossils
Phenotype
The physical expression of the genotype; it may be influenced by the environment
Population genetics
A specialty within the field of genetics; it focuses on the changes 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 of biological relationships over time
Taxonomy
The classification of past and living life-forms
Uniformitarianism
The theory that processes that occurred in the geologic past are still at work today
Adaptations
Changes in physical structure, function, or behavior that allow an organism or species to survive and reproduce in a given environment
