Unit I Biology vocab
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71 terms
Terms | Definitions |
|---|---|
 Lamarck | "Use and disuse" ; "inheritence of acquired characteristics" |
| Darwin | "Origin of the Species"; proposed that species change through natural selection |
| Evolutionary adaptation | An accumulation of inherited characteristics that enhance an organism's ability to survive and reproduce in specific environments |
| Taxonomy | the branch of biology concerned with naming and classifying organisms |
| Uniformitarianism | Same geologic processes are operating today as in the past, and at the same rate; developed by charles lyell |
| Catastrophism | Extinctions of life= common occurrence; suddden; opposed gradual evolutionary change |
| Parallel evolution | Convergent evolution; similar ecological roles |
| Artificial selection | Breeding with and for desired traits |
| Homology | Darwin's explanation on why certain characteristics in related species have an underlying similarity even though they have different functions |
| Homologous structures | Represent variations on a structural theme that was present in their in their common ancestor |
| Vestigial organs | Structures of marginal importance to the organism, remnants of structures that served important functions in the organism's ancestors |
| Endemic | Found no where else in the world |
| Microevolution | Change in the genetic makeup of a population from generation to generation |
| Mendel | Father of genetics; "parents pass on 'discrete heritable units'" |
| Popular genetics | Study of how populations change genetically over time |
| Modern synthesis | Comprehensive theory of evolution that integrated ideas from many other fields |
| R.A. Fisher | Demonstrated the rules by which Mendelian characteristics are inherited |
| Population | Localized group of individuals that are capable of interbreeding and producing fertile offspring; may be isolated from each other |
| Gene pool | Total aggregate of genes in a population at any time |
| Hardy-weinberg Theorem | Frequencies of alleles and genotypes in a population's gene pool remain constant from generation to generation, provided that mendelian segregation and recombination of alleles are at work |
| Hardy-Weinberg Equilibrium | State in which population has the same allele frequencies from generation to the next (and thus is considered to be not evolving) |
| stabilizing selection | Against extreme phenotype and favors intermediate variants |
| Balanced polymorphism | State that occurs when natural selection maintains several phenotype forms in a population |
| Pseudogenes | Inactivated by mutation, genetic "noise" free to accumulate |
| Heterozygote advantage | Greater fitness than the homozygous, natural selection will tend to maintain two or more alleles |
| Sexual dimorphism | Differences between the sexes to secondary sexual characteristics |
| Intrasexual selection | "Within the same sex", competition among individuals of same sex for the opposite sex |
| Intersexual selection | Between males and females; females usually make choice, individuals are choosy in selecting their mates; depends on showiness and behavior |
| Mutation | Changes in the nucleotide sequence of DNA; most occur in somatic cells, but only these in gametes can be passed on |
| Duplication | Copying of loci, important source of variation |
| Genetic drift | Similar deviations from the expected result; occur because populations are finite in size; reduce genetic variation than losses of alleles from gene pool |
| Bottlenecker effect | Sudden change;gene pool may no longer be reflective of original population |
| Founder effect | Isolation to smaller group establishing a new population whose gene pool is not reflective of original. |
| Gene flow | genetic additions or subtration from a population resulting the movement of fertille individuals or gametes |
| Discrete characters | determined by a single gene locus with different alleles that produce distinct phenotypes |
| Quantitative characters | Vary along a continuum within a population, heritable when resulting from the influence of two or more genes on a single phenotypic character |
| Morph | The different forms when individuals display a differ in a discrete character |
| Phenotypic polymorphism | Two or more distinct morphs are each represented in high enough frequencies to be readily noticeable |
| Genetic polymorphisms | Alleles at several loci |
| average heterozygosity | Average % of loci that are heterozygous |
| Cline | A graded change in a trait along a geographic |
| Fitness | The contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals |
| Relative fitness | Contribution of a genotype is the next generation compared to the contributions of alt. Genotypes for the same locus |
| Directional selection | A population's environment changes or when members of a population migrate to a new habitat with different environmental conditions than their former one; shifts frequency curve for some phenotype characteristics |
| Disruptive selection | Occurs when environmental conditions favor individuals on both extremes of a phenotypic range over intermediate phenotypes |
| Speciation | Focal point of evolutionary theory because appearance of new species is the source of biological diversity |
| Microevolution | Confined to a single gene pool/population; explain how new species originate and develop |
| Macroevolution | Evolutionary change about the species level |
| Anagenesis | Phyletic evolution: accumulation of changes that gradually transform a given species into a species with different characteristics |
| Cladogenesis | Branching evolution; splitting of a gene pool into two or more separate pools; rise to one or more new species |
| biological species concept | A species as a population or a group of populations whose members have the potential to interbeed in nature and produce viable, fertile offspring |
| Reproductive isolation | Existence of biological factors that impede members of two species from reproducing fertile hybrids |
| Prezygotic barriers | Impede mating between species to hinder the fertilization of ova |
| Postzygotic barriers | prevent zygote from developing |
| Morphological species concept | Characterizes physical aspects ; can be useful even without gene flow |
| Ecological species concept | Species in terms of ecological niche; can accommodate asexual species as well |
| Phylogenetic species concept | Defines a species to a set of organisms with a unique genetic history |
| Punctuated equilibrium | periods of apparents stasis punctuated by sudden change |
| Allopatric speciation | Gene flow is interrupted when a population is divided into geographically isolated subpopulations |
| Sympatric speciation | Geographically overlapping populations |
| Autopolyploid | Individual that has more than two chromosome sets; all derived from a single species |
| Allopolyploid | Fertile with one another but cannot interbreed with parental species |
| Exaptations | Structures that evolve in one context but became co-opted for another function; distinguish them from the adaptive origin of the original structure |
| Heterochrony | Many striking evolutionary transformations; an evolutionary change in the rate or timing of developmental events |
| Allometric growth | Proportioning that helps gives a body its specific form |
| paedomorphosis | Reproductive development accelerates compared to somatic developing, the secuality mature stage of a species may retain body features that were juvenille structures in an ancestral species |
| Homeotic genes | Determine such basic features as where a pair of wings and a pair of legs will develop |
| Species selection | The species that endure the longest and generate the most offspring determine the directiong of major evolutionary trends |
| Adaptive Radiation | many new species arise from one common ancestor |
| Heterochrony | an evolutionary change in the rate or timing of developmental events |
| Cladogram | Depicts patterns of shared characteristics among taxa and forms the basis of a phylogenetic tree |
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