Geology Ch 6
Terms
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- clams and brachiopods are very distantly related but possess a number of similarities because of
- convergent evolution
- to be members of a species, organisms must
- interbreed and produce fertile offspring
- main sources of variation in populations
- sexual reproduction and mutations
- first step in natural selection
- variation must be produced and maintained in interbreeding populations
- conducted breeding experiments with garden peas
- Gregor Mendel
- Convergent evolution
- process whereby organisms not monophyletic (not closely related), independently evolve similar traits as a result of having to adapt to ecological niches or similar environments
- evolution by natural selecion is what kind of process
- two-step process
- speciation resulting from isolation of a small part of an interbreeding population
- allopatric
- first formal threory of evolution to be taken seriously was proposed by
- Jean Baptiste de Lamarck
- Darwin's idea was that
- the natural processes select favorable variants for survival
- development of similar adaptive types in different groups of organisms results from
- parallel and convergent evolution
- genes, the basic units of inheritance, are specific segments of
- chromosomes
- type of cell division that produces functional sex cells containing one-half of the chromosomes typical of all species
- meiosis
- only genes in these type of cells are inheritable
- sex cells
- new species arise rapidly, perhaps in a few thousand of years
- punctuated equilibrium
- second step in natural selection
- favorable variants must be selected for survival
- evidence for evolution
- 1) the way organisms are classified, 2) comparative anatomy and embryology, 3) biochemical similarities, 4) small-scale evolution, and 5) the fossil record
- genetic information is carried in
- chromosomes of cells
- Wallace and Darwin proposed this as the mechanism for evolutionary change
- natural selection
- hereditary determinates in all organism
- genes
- organs containing the same basic structural elements, such as a bird's wing and dog's forelimb
- homologous
- Lamarch's mechanism for evolution
- inheritance of aquired characteristics
- diversification of a species into two or more descendant species
- divergent evolution
- all of the genes available to an interbreeding populations constitute its
- gene pool
- Divergent evolution
- occurs when two or more biological characteristics have a common evolutionary origin but have diverged over evolutionary time
- genes controlling the same trait occur in different forms known as
- alleles
- Darwin formulated this idea using
- observations of variation in natural populations and artificial selection and his reading of Thomas Malthus's essay on population
- a group is isolated from its parent population, gene flow is restricted or eliminated, and the isolated group is subjected to different selection pressures
- allopatric speciation
- chromosomes are complex molecules of
- deoxyribonucleic acid
- adaptive radiation during which an ancestral stock gives rise to diverse species
- divergent evolution
- most variation is maintained in populations by
- sexual reproduction and mutations
- the garden pea experiments provided
- some of the answers regarding how variation is maintained and passed on
- his work is the basis for modern genetics
- Mendel
- first person to prpose a formal theory of evolution
- Jean Baptiste de Lamarck
- organisms are assigned to genera, families, and orders on the basis of
- shared characteristics
- simultaneously published their views on evolution in 1859
- Alfred Russell Wallace and Charles Darwin