Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
60 Cards in this Set
- Front
- Back
|
Adaptation |
A process by which an organism becomes better suited to its environment OR an inherited feature resulting from natural selection that makes an organism better suited to its environment |
|
|
Adaptive Radiation |
The relatively sudden evolution of many new species from a single ancestral species to fill a variety of different environments/niches |
|
|
Alleles |
Alternative forms of genes |
|
|
Allopatric Species |
Two species or populations that are separated geographically |
|
|
Allopatric Speciation |
The formation of new species from populations that are geographically separated from each other |
|
|
Allopolyploidy |
A polyploid individual (having more than two sets of chromosomes) resulting from two different species interbreeding |
|
|
Amphiploidy |
A mistake in mitosis that results in a cell with double the normal number of chromosomes. Can lead to the formation of new species (particularly in plants). Also called somatic doubling. |
|
|
Autopolyploidy |
A polyploid individual resulting from two individuals of the same species breeding. |
|
|
Analogous structures |
Features that are similar in function but evolved independently from different ancestors e.g. wings in incests and birds |
|
|
Behavioural Barrier |
Barrier to gene flow such as courtship displays in birds that prevent interbreeding of closely related species |
|
|
Biogeography |
Study of the geographic distribution of organisms |
|
|
Bottleneck Effect (Genetic Bottleneck) |
The reduction in genetic diversity in a gene pool when a population is reduced to only a few individuals |
|
|
Cline |
A gradual change in the phenotypes of a species over a geographical gradient (e.g. up a mountain) |
|
|
Co-evolution |
An evolutionary change in one species in response to a change in another species |
|
|
Common ancestor |
Original species from which others develop through evolution |
|
|
Comparative anatomy |
Comparing physical structures in related species. Sometimes used as evidence for evolution |
|
|
Comparative embryology |
Comparing the stages of development of embryos in related species. Sometimes used as evidence for evolution |
|
|
Competition |
When organisms living in the same location require the same resources |
|
|
Convergent evolution |
Occurs when unrelated or distantly related species evolve to resemble each other due to similar selection pressures e.g. penguin, shark, seal |
|
|
Deme |
A local interbreeding population of a species |
|
|
Directional Selection |
Natural selection that favours one end of a range of phenotypic variation usually due to a changing environment |
|
|
Disruptive selection |
Natural selection that favours both ends of the range of phenotypic variation, and which can lead to the formation of two new species |
|
|
Divergent Evolution |
Where one species evolves into two or more different species |
|
|
Endemic species |
Species native to a particular area and only found there |
|
|
Evolution |
Genetic changes to populations that in time can lead to new types of organisms (e.g. new species) |
|
|
Extinction |
When all members of a particular population or species die |
|
|
Fitness |
The relative breeding success of an individual. Those individuals that breed most and produce most offspring for the next generation are the fittest |
|
|
Fossil record |
Remains or impressions of ancient organisms. Often used as evidence for evolution |
|
|
Founder Effect |
The reduction in genetic diversity of a population due to its formation from only a small number of individuals. |
|
|
Gamete Incompatibility |
Prezygotic barrier to gene flow where the sperm and egg of two different species differ preventing fertilisation occurring. This prevents interbreeding of closely related species |
|
|
Gene flow |
Exchanging of alleles between populations through immigration and emigration |
|
|
Gene pool |
All of the alleles in a population |
|
|
Genetic drift |
Changes in allele frequency in a population due to chance events. Has a greater impact on small populations. |
|
|
Geographic Barrier |
A barrier to gene flow such as a river, mountain range, lake, etc. that prevents populations or closely related species from interbreeding. Important in the process of allopatric speciation |
|
|
Gradualism |
Proposed model of the rate of evolution where evolution produces new species at a slow and steady rate (as opposed to Punctuated Equilibrium) |
|
|
Homologous Structures |
Structures that have a common evolutionary origin (same ancestors) but may have different functions e.g. forelimbs in mammals and birds |
|
|
Hybrid |
Offspring from a cross between individuals of two different species |
|
|
Hybrid Disadvantage |
One of the Postzygotic barriers ro reproduction between closely related species. A zygote is produced and the hybrid may be fertile, but it is not well adapted to the environment. |
|
|
Hybrid Inviability |
One of the Postzygotic barriers to reproduction between closely related species. A zygote is produced but does not develop properly and dies. |
|
|
Hybrid Sterility |
One of the Postzygotic barriers to reproduction between closely related species. A zygote is produced but the hybrid produced is sterile and so cannot produce offspring. |
|
|
Instantaneous Speciation |
Where new species appear "instantly" rather than over a long period of time -usually due to polyploidy. It is am example of Sympatric Speciation. |
|
|
Introduced Species |
Species that are not native to a particular area, but have been brought there by humans e.g. rats in NZ |
|
|
Native Species |
Species that are naturally found in a particular area e.g. kiwis in NZ |
|
|
Natural Selection |
Individuals in a population best suited to the environment survive better, produce the most offspring, passing on their particular genes and therefore leading to evolutionary change in the population |
|
|
Niche |
The particular role a species plays in the environment in which it lives |
|
|
Non-disjunction |
The failure of the chromosome or chromatids to separate into different cells during meiosis. Can lead to the production of diploid gametes |
|
|
Parallel Evolution |
Similar features evolve in related species due to similar selection species |
|
|
Polyploidy |
Having three or more copies of chromosomes |
|
|
Population |
Group of individuals from the same species living in the same geographical location |
|
|
Postzygotic Reproductive Isolating Mechanisms |
Barriers to successful interbreeding between closely related species thag occur after fertilisation e.g. Hybrid Sterility |
|
|
Prezygotic Reproductive Isolating Mechanisms |
Barriers to successful interbreeding between closely related species that occur before fertilisation e.g. Gamete incompatibility |
|
|
Punctuated Equilibrium |
Proposed model of the rate of evolution where there are long periods of little change (stasis) in a species with short bursts of rapid change resulting in the formation of a new species (as opposed to Gradualism) |
|
|
Ring species |
A special type of cline where the demes are arranged in a circle across the species range and the demes at the end, although geographically close, may not be able to interbreed |
|
|
Selection Pressure |
The strength of natural selection for or against a particular trait |
|
|
Sequential evolution |
Occurs when one species into another over time |
|
|
Species |
A group of organisms who cam interbreed and produce fertile offspeing |
|
|
Structural barrier |
Barrier to gene flow such as differences in the reproductive organs of species that prevent interbreeding of closely related species |
|
|
Sympatric Speciation |
Where new species form without a geographical barrier (unlike Allopatric Speciation). Examples include Ecological Speciation and Instantaneous Speciation (e.g. Polyploidy) |
|
|
Temporal Barrier |
Barrier to gene flow such as breeding at different times of the year that prevents interbreeding of closely related species |
|
|
Zygote |
Cell produced by joining an egg and a sperm |
