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| Alternative form of a single gene controlling different versions of the same trait. |
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| Model for the evolution of a new species from a small, geographically isolated part of a larger parent population. |
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| Body part, such as wings of insects and birds, that serves the same function but differs in structure and development. |
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| The practice of selectively breeding plants and animals for desirbale traits. |
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| The actual remains of an organism, such as bones, teeth, shells, and rarely the soft parts. |
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| Double-stranded, helical molecule of deoxrybonucleic acid (DNA); specific segments of chromosomes are genes. |
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| A type of analysis of orgainisms in which they are grouped together on the bases of derived as opposed to primitive characteristics. |
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| A diagram that shows the probable evolutionary relationships among members of a clad. A group of organisms including their most recent common ancestor. |
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| The development of similar features in two or more distantly relating groups of organisms resulting from adapting to a comparable lifestyle. |
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| Deoxyribonucleic Acid DNA |
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| The chemical substance of which chromosomes are composed; the genetic material in all organisms. |
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| The diversification of a species into two or more descendant species. |
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| Remains or traces of prehistoric organisms preserved in rocks. |
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| A specific segment of a chromosome constituting the basic unit of heredity. |
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| Body part in different organisms that has a similar structure, similar relationships to other structures and similar development but does not necessarily serve the same function. For example, forelimbs in whales, dogs, and bats. |
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| Inheritance of acquired characteristics |
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| Jean Baptist de Lamarck's mechanism for evolution; holds that characteristics acquired during an individual's lifetime can be inherited by descendants. |
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| Greatly accelerated extinction rate that results in a marked decrease in biodiversity, such as the mass extinction at the end of the Cretaceous period. |
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| Cell division that yeilds sex cells, sperm and eggs in animals and pollen and ovules in plants, in which the number of chromosomes is reduced by half. |
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| Cell division that results in two cells that have the same number of chromosomes as the parent cell; takes place in all cells except sex cells. |
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| A combination of ideas of scientists regarding evolution that includes chromosome theory of inheritance, mutations as a source of variation, and gradualism,but rejects the idea of inhertance of acquired characteristics. |
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| the concept that not all parts of an organism evolve at the same rate, thus yeilding organisms with features retained from the acestral condition |
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| A change in the genes of organisms; yeilds some of the variation on which natural selection acts. |
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| A mechanism that accounts for differential survival and reproduction among members of a species; the Mechanism proposed by Darwin and Wallace to account for evolution |
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| The use of fossils to study life history and relationships among organisms. |
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| The development of similar features in tow or more closely related but seperate lines of descent as a consequence of similar adaptations. |
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| The concept that a species evolves gradually and continuously as it gives rise to new species. |
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| A concept holding that a new species evolves rapidly, in perhaps a few thousand years, and then remains much the same during its several million years of existence. |
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| A population of similar individuals that in nature can interbreed adn produce fertile offspring. |
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| The theory holding that all oraganisms are related and that they descended with modification from organisms that lived during the past. |
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| Any indication of prehistoric organic activity such as tracks, trails, and nests preserved in rocks. |
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| Structure in an organism that no longer serves any or only a limited function, such as dewclaws in dogs and wisdom teeth in humans. |
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