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Evolution Key Words

Key words Version 1 (not sure who gave me this so thanks in advance)

Adaptive radiation

The evolution of a number of different species of plant or animal from one ancestral species, eg. Darwin’s Galapagos finches.

Allopatric speciation

Speciation occurring where organisms are initially capable of actually interbreeding but cannot because they are geographically separated.

Allopatry

Describes groups of organisms that could potentially interbreed but do not because they are geographically separated.

Analogous structures

Structures that are superficially similar but have evolved in different ways, eg. the wings of birds, bats and insects.

Ancestral type

A hypothetical individual possessing the ancestral or primitive characteristics of a group of species.

Artificial selection

Deliberate selection by humans for desired features in a plant or animal species.

Autopolyploidy

A type of polyploidy where the multiple sets of chromosomes are all derived from the same species.

Cladistics

A method of classification in which animals and plants are placed into groups called clades when they share characteristics that are thought to indicate common ancestry.

Classification

The arrangement of organisms into a series of groups based on physiological, biochemical, and anatomical or other relationships.

Cline

A gradual variation in the characteristics of a species or population over its geographical range.

Convergent evolution

The development of superficially similar structures in unrelated organisms, usually because the organisms live in the same kind of environment.

Divergent evolution

An accumulation of changes in the gene pools of two (or more) populations, leading to the formation of races, sub-species, species etc.

Evolution

The gradual process by which the present diversity of plants and animals arose from the earliest and most primitive organisms.

Geological record

Fossils preserved in sedimentary rock layers that can be used to trace the evolutionary history of a species.

Homologous structures

Structures that have a similar evolutionary history but have developed to suit different functions, eg. wings of a bat, flippers of dolphins and arms of humans have all evolved from paired pectoral fins of an ancestral fish.

Hybrid

The offspring of a mating where the parents differ in at least one characteristic. The term is usually applied to offspring of widely different parents, eg. different varieties/species.

Instant speciation

The formation of a new species through autopolyploidy or allopolyploidy. Because the chromosome numbers of the new ‘instant’ species do not match that of the original species they cannot interbreed.

Macro-evolution

The formation of a completely new species, genera, etc.

Micro-evolution

The accumulation of (through mutation) of new characteristics in a species.

Natural selection

The process that brings about new species by eliminating individuals that are less well adapted to their current environment from a population showing variation, allowing mainly individuals with advantageous adaptations to survive and reproduce.

Parallel evolution

The development of related organisms along similar evolutionary paths due to strong selection pressures acting on all of them in the same way.

Phyletic speciation or Sequential speciation

Speciation where adaptation by a species to changing environments creates a new species. This occurs because along with adaptations to the environment, barriers to breeding with the ‘original’ species are developed.

Phylogeny

The evolutionary history of an organism or a group of related organisms.

Polymorphism

The existence of three or more distinctly different forms within a plant or animal species, eg. the different ‘castes’ found in social insects such as bees or ants.

Primitive feature

A feature that is assumed to have been present in the evolutionary ancestor of a species of group of species. It may or may not have been simpler, depending on the evolutionary history of the species.

 

Reproductive isolation

A barrier to breeding that exists due to differences in mating season or mating organs, eg. flowers flowering at different times of year.

Ring species

Two apparently distinct species that are connected by a series of intermediate geographical and structural subspecies between which interbreeding can occur.

Selection pressure

The extent to which organisms possessing a particular characteristic are either eliminated or favoured by environmental demands.

Speciation

The development of one or more species from an existing species. It occurs when sympatric or allopatric populations diverge so much from the parent population that interbreeding cannot occur.

Species

A category used in the classification of organisms that consists of a group of organisms that can usually breed together and produce fertile offspring.

Sub-species

A group of individuals within a species that breed more freely among themselves than with other members of the species and resemble each other in more characteristics.

Sympatric speciation

Speciation occurring where organisms living within the same area are theoretically capable of interbreeding, but cannot because of difference in behaviour, flowering time etc.

Sympatry

Describes groups of organisms that live in the same geographical area.

The new synthesis

Also referred to as ‘neo-Darwinism’. It combines the ideas of Darwin with the discoveries of Mendel and forms the basis of modern evolutionary science.

Vestigial organ

Any part of an organism that has diminished in size during its evolution because the function it serves has decreased in importance, eg. the appendix in humans.


Key words Version 2


adaptive radiation - when a large number of species form to occupy different ecological niches

allopatry - speciation as a result of geographical isolation

allopatric speciation - speciation occurring where organisms are initially capable of actually interbreeding but cannot because they are geographically separated

analogous structures — structures which have the same job but have different bone make up e.g. wings of a bird, bats and insects. Do not share a common ancestor

biogeography — the study of the geographic distribution of organisms

dine — a gradual variation in the characteristics of a species or population over a geographical range

co-evolution - when one species or group changes its genetic composition in response to a genetic change in another

convergent evolution - when different species living in the same environment come to look similar

divergent evolution - when one species branches to form two or three species

embryology — the study of how embryos develop, looking at which genes are turned on and when

endemic — only found naturally in a certain country or area

evolution — the gradual process by which the present diversity of plants and animals arose from earliest and most primitive organisms

genetic drift — the important random fluctuation in the frequencies of alleles due to chance events

geographic or topographic barrier — a physical barrier (for the species) that prevents gene flow. e.g. a mountain ridge may be a barrier for an insect

gradualism - slow changes between populations that occur as a result of different selection pressures

homologous structures — structures which have a similar evolutionary history but have developed to suit different functions e.g. wing of bat, flipper of dolphin and arm of human

hybrid — an individual formed by mating between genetically different populations or species

instant speciation — the formation of a new species through autopolyploid or allopolyploid. Because the chromosome numbers of the new ‘instant’ species do not match that of the original species they cannot interbreed

isolating mechanism - any mechanism that prevents interbreeding of hybrids

parallel evolution — the development of related organisms along similar evolutionary paths due to strong selective pressures acting on all of them in the same way

polyploidy - when cells have more than 2n chromosomes common in plants

punctuated equilibrium - where evolution consists of long periods of stability, followed by short rapid changes as a result of critical selection pressures

reproductive isolation — a barrier to breeding that exists due to differences in mating seasons or mating organs e.g. flowers flowering at different times of the year

ring species — two apparently distinct species that are connected by a series of intermediate geographical and structural subspecies between which interbreeding can occur

selection pressure - the environmental factors that favour certain phenotypes

speciation - a mechanism by which new species are formed species - a group of individuals with common features and ancestry, which will interbreed

sympatry - speciation within the same area by natural selection; there are a number of niches and groups move into the niches best suited to them

temporal barrier — when gene flow is prevented due to the populations or species having different mating times of day, month or year

vestigial organ — any part of an organism that has diminished in size during its evolution because the function it serves has decreased in importance e.g. the appendix in humans


And some more (:


•Phylogenetics: the study of evolutionary relatedness between groups of organisms. Relatedness is determined by DNA sequencing data and comparing morphological data
•Phylogeny: The evolutionary development and history of a species or higher taxonomic grouping of organisms.
•Cladogram: Diagram which shows ancestral relations between organisms


•Cladistics: method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants (and nothing else).
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