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60 Cards in this Set
- Front
- Back
Group Selection |
Notion largely discredited by the rise of darwinian theory proposing that animals act for the good of their social group or of their species. |
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kin selection |
Principle that animals behave preferentially toward their genetic kin; formulated by william hamilton. |
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inclusive fitness |
Reproductive success of an organism plus the fitness of its close kin. |
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adaptationism |
A premise that all aspects of an organism have been molded by natural selection to a form optimal for enhancing reproductive success. |
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reductionism |
Paradigm that an organism is the sum of many evolved parts and that organisms can best be understood through an adaptationist approach. |
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null hypothesis |
The strarting assumption for scientific inquiry that ones research results occur by random chance. Ones hypothesis must challenge this initial assumption. |
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hardy-weinberg equilibrium |
The theoretical distribution of alleles in a given population in the absence of evolution, expressed as a mathematical equation. |
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parapatric speciation |
Speciation occurring when two populations have continuous distributions and some phenotypes in that distribution are more favorable than others. |
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gradualism |
Darwinian view of slow, incremental evolutionary change |
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macroevolution |
large scale evolutionary change over a long time period or evolution of major phenotypic changes over relatively short time periods. |
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punctuated equilibrium |
model of evolution characterized by rapid bursts of change, followed by long periods of stasis. |
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reproductive isolating mechanisms (RIMs) |
any factor behavioral, ecological, or anatomical that prevents a male and female of two different species from hybridizing |
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anagenesis |
evolution of trait or a species into another over a period of time |
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cladogenesis |
evolution through the branching of a species or a lineage. |
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allopatric speciation |
speciation occuring via geographic isolation. |
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analogous |
having similar traits due to similar use, not due to shared ancestry. |
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convergent (or parallel) evolution |
similiar form or function brought about by natural selection under similiar environments rather than shared ancestry |
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cladogram |
branching diagram showing evolved relatiohips among members of a lineage |
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species |
an innterbreeding group of animals or plants that are reproductivelly isoltaed through anatomy, ecology, behavior, or geographic distribution from all other such groups. |
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speciation |
formation of one or more new species via reproductive isolation |
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biological species concept |
defines species as interbreeding populations reproductively isolated from other such populations |
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systematics |
branch of biology that describes patterns of organismal variation |
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homology |
similarity of traits resulting from shared ancestry |
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genetic bottleneck |
temporary dramatic reduction in size of a population or species |
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sexual selection |
differntial reproductive success within one sex of any species |
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sexual dimorphism |
difference in size, shape, or color, between the sexes |
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reproductive potential |
the possible offspring output by one sex |
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reproductive variance |
measure of variation from the mean of a population in the reproductive potential of one sex compared with the other |
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gene flow |
movement of genes between populations |
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inbreeding |
mating between close relatives |
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genetic drift |
random changes in gene frequency in a population |
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founder effect |
a component of genetic drift theory, stating that new populations that become isolated from the parent population carry only the gentic variation of the founders |
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directional selection |
natural selection that drives evolutionary change by selecting for greater or lesser frequency of a given trait in a population |
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stabilizing selection |
selection that maintains a certain phenotype by selecting against deviations from it. |
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phenylketonuria (PKU) |
autosomal recessive condition that leads to the accumulation of large quantities of the amino acid phenylalanine, causing mental retardation and other phenotypic abnormalities |
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polygenic traits |
phenotypic traits that result from the combined action of more than one gene; most complex traits are polygenic |
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pleiotropy |
the phenomenon of a single gene having multiple phenotypic effects |
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heritability |
the proportion of toatl phenotypic variability observed for a given trait that can be ascribed to genetic factors. |
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quantitative variation |
phenotypic variation that is characterized by the distribution of continuous variation (expressed using numerical measure) within a population (for example, in a bell curve) |
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qualitative variation |
phenotypic variation that can be characterized as belonging to discrete, observable categories. |
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x-linked disorders |
genetic conditions that result from mutations to genes on the X chromosome. They are almost always expressed in males, who have only one copy of the X chromosome; in females, the second X chromosome containing the normally functioning allele protects them from developing x-linked disorders. |
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insertion mutation |
a change in the base sequence of a gene that results from the addition of one or more base pairs in the DNA |
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deletion mutation |
A change in the base sequence of a gene that results from the loss of one or more base pairs in the DNA |
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trinucleotide repeat diseases |
A family of autosomal dominat diseases that is caused by the insertion of multiple copies of a three-base pair sequence (CAG) that codes for the amino acid glutamine. Typically, the more copies inserted into the gene, the more serious the disease. |
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autosomal dominant disease |
A disease that is caused by a dominant allele: only one copy needs to be inherited from either parent for the disease to develop. |
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point mutation |
A change in the base sequence of a gene that results from the change of a single base to a different base |
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sickle cell disease |
An autosomal recessive disease caused by a point mutation in an allele that codes for one of the polypeptide chains of the hemoglobin protein. |
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autosomal recessive disease |
A disease caused by a recessive allele; one copy of the allele must be inherited from each parent for the disease to develop. |
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linkage |
Genes that are found on the same chromosome are said to be linked. The closer together two genes are on a chromosome, the greater the linkage and the less likely they are to be separated during crossing over. |
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mendels law of independent assortment |
Genes found on differ chromosomes are sorted into sex cells independently of one another |
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mendels law of segregation |
The two alleles of a gene found on each of a pair of chromosomes segregate independently of one another into sex cells. |
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particulate inheritance |
The concept of heredity based on the transmission of genes (alleles) according to Mendelian principles. |
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codominant |
In a diploid organism, two different alleles of a gene that are both expressed in a heterozygous individual |
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dominant |
In a diploid organism, an allele that is expressed when present on only one of a pair of homologous chromosomes. |
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recessive |
In a diploid organism, refers to an allele that must be present in two copies (homozygous) in order to be expressed. |
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ABO blood type system |
Refers to genetic system for one of the proteins found on the surface of red blood cells. Consists of one gene with three alleles: A,B, and O. |
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Phenotype |
An observable or measurable feature of an organism Phenotype's can be anatomical, biochemical, or behavioral. |
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Genotype |
The genetic makeup of an individual. Genotype, can refer to the entire genetic complement or more narrowly to the alleles present at a specific locus on two homologous chromosomes. |
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Regulatory genes |
Guide the expression of structural genes, without, coding for a protein themselves. |
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Structural genes |
Genes that contain the information to make a protein. |