Chapter 20 Flashcards
The orderly sequence of events that occurs as an organism grows and matures
Development
The evolution of a new species
Speciation
Reproductive isolating mechanisms that prevent fertilization from taking place
Prezygotic Barriers
The most common method of speciation and accounts for almost all evolution of new animal species
Allopatric Speciation
A population is declared a separate species if it has undergone evolution long enough for statistically significant differences in diagnostic traits to emerge
Phylogenetic Species Concept
The continuous, low-level extinction of species
Background Extinction
When fertilization happens between gametes of two closely related species despite the existence of prezygotic barriers
Postzygotic Barriers
Speciation that occurs when one population becomes geographically separated from the rest of the species and subsequently evolves by natural selection and/or genetic drift
Allopatric Speciation
The science of naming, describing, and classifying organisms
Taxonomy
A taxonomic subdivision of a species
Subspecies
The end of a lineage, occurs when the last individual of a species dies
Extinction
Genetic exchange between two groups is prevented because they reproduce at different times of the day, season, or year
Temporal Isolation
Who was Linnaeus?
The 18th century biologist who founded modern taxonomy
New ecological opportunities that were not exploited by an ancestral organism
Adaptive Zones
The inability of a hybrid to reproduce because of some defect
Hybrid Breakdown
The egg and sperm of different species are incompatible
Gametic Isolation
The number of chromosome sets making up an organism’s genome
Ploidy
The genes from parents belonging to different species do not interact properly in regulating the mechanisms for normal development
Hybrid Inviability
When a new species evolves within the same geographic region as the parental species
Sympatric Speciation
A species consists of one or more populations whose members interbreed in nature to produce fertile offspring and do not interbreed with
Biological Species Concept
What are the 3 evolutionary processes that may occur in hybrid zones?
- Reinforcement
- Fusion
- Stability
Contains multiple sets of chromosomes from two or more species
Allopolyploidy
The hybrids in a hybrid zone are as fit as either of the parental populations
Fusion
Two closely related species may be found in the same geographic area, they usually live and breed in different habitats in that area
Habitat Isolation
The increase in reproductive isolation that often occurs over time in a hybrid zone
Reinforcement
The evolutionary diversification of many related species from one or a few ancestral species in a relatively shorty period
Adaptive Radiation
Choosing a mate based on its color or some other characteristic
Sexual Selection
When incompatible structures of the genital organs prevent successful mating
Mechanical Isolation
The possession of more than two sets of chromosomes
Polyploidy
Exert control over hundreds of other genes during development
Regulatory Genes
Problems during meiosis cause the gametes of an interspecific hybrid to be abnormal
Hybrid Sterility
An evolutionary process in which the hybrids are more fit than either parental population
Stability
Type of model in which evolution proceeded continuously over long periods
Phyletic Gradualism
Sexual reproduction between individuals from closely related species
Hybridization
An area of overlap between two recently diverged populations in which interbreeding takes place and hybrid offspring are common
Hybrid Zone
The concept of distinct kinds of organisms
Species
Animal species that exchange a distinctive series of signals before mating
Behavioral Isolation
Areas of transition between two different environments
Ecotones
Contains multiple sets of chromosomes from a single species
Autopolyploidy
Large-scale phenotypic changes in populations that generally warrant their placement in taxonomic groups at the species level and higher
Macroevolution
What model was proposed by paleontologists who questioned whether the fossil record really is as incomplete as it initially appeared
Punctuated Equilibrium Model
