Chapter 3 Flashcards
Darwinian Evolution
Natural Selection
- Individuals with favorable characteristics necessary for survival will posses an advantage over others and pass down their genes dominating others.
What is Adaptation?
adaptation, is the adjustment of organisms to their environment in order to improve their chances at survival in that environment.
What are Alleles?
All the different forms that a particular gene might take
Aptation
The shaping of any useful feature of an organism, regardless of that feature’s origin
What are chromosomes?
Sets of paired bodies in the nucleus of cells that are made of DNA and contain the hereditary genetic information that organisms pass on to their offspring
What is common ancestry?
Darwin’s claim that similar living species must all have had a common ancestor
What is Continuous Variation?
A pattern of variation involving polygeny in which Phenotypic traits grade imperceptibly from one member of the population another without sharp breaks
What is Discontinuous Variation?
A Pattern of phenotypic variation in which the phenotype exhibits sharp breaks from one member of the population to the next
What is DNA?
(Deoxyribonucleic Acid)
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The structure that carries the genetic heritage of an organism as a kind of blueprint for the organism’s construction and development
What is Evolution?
The process of change over time
What is Evolutionary Theory?
The set of testable hypotheses that assert that living organism can change over time and give rise to new kinds of organisms, with the result that all organisms ultimately share a common ancestry.
What is Exaptation
Any exaptation is defined as any adaptation that performs a function different from the function that it originally held.
What is a Gene?
The portion or portions of the DNA molecules that code for proteins that shape phenotypic traits
What is a Genome
The genetic information about particular biological traits encoded in an organism’s DNA
What is Genus?
a taxonomic category ranking used in biological classification that is below family and above species.
The level of the Linnaen taxonomy in which different species are grouped together based on their similarities to one another. In modern taxonomies, genus is ranked between family (less specific) and species (more specific)
What is a Linnaean system?
a classification system for the natural world to standardize the naming of species and order them according to their characteristics and relationships with one another.
What is Heterozygous?
Describes a fertilized egg that receives a different particle (or allele) from each parent for a particular trait
What is Homozygous?
Describes a fertilized egg that receives the same particle (or allele) from each parent for a particular trait
What is Mendelian Inheritance?
The view that heredity is based on non-blending, single-particle genetic inheritence
What is Mutation?
a spontaneous random change in the chemistry of DNA
What is Natural Selection
Natural selection is a mechanism of evolution. Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success. This process causes species to change and diverge over time.
What is Niche Construction?
Niche construction theory (NCT) is a fledgling branch of evolutionary biology that places emphasis on the capacity of organisms to modify natural selection in their environment and thereby act as co-directors of their own, and other species’, evolution.
Norm of Reaction
A table or graph that displays the possible range of phenotype outcomes for a given genotype in different environments
What is Pangenesis
A theory of heredity suggesting that an organism’s physical traits are passed on from one generation to the next in the form of multiple distinct particles given off by all parts of the organism, different proportions of which get passed on to offspring via sperm or egg
What is a Phenotype
The observable, measurable, overt characteristics of an organism
What is pleiotropy
The observable, measurable, over characteristics of an organism
What is Polygeny
The phenomenon whereby many genes are responsible for producing a phenotype trait, such as skin colour.
What is the Principle of Segregation?
A principle of mendelian inheritence in which an individual gets one gene for each trait from each parent
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how pairs of gene variants are separated into reproductive cells
What are Species
A reproductive community of populations that occupies a specific niche in nature
What is Taxonomy?
In Biology, a classification system used to organize various kinds of organisms
What is Variational Evolution
The Darwinian theory of evolution, which assumes that variant members of a species respond differently to environmental challenges those variants that are more successful (“fitter”) survive and reproduce more offspring, who inherit the trai that made their parents fit.
Pre-Darwinian Views of the Natural world
Great Chain of Being
Catastrophism
Uniformitarianism
Transformational Evolution
What is learning
Species developing new behaviour to adapt to surroundings
What is Instinct
Hardwired behaviour
What is Acclimatization
Is a physiological response within individuals to environmental pressure
What is Genetic adaptation
Are Changes within populations in response to selection pressure
Directional selection
Evolution that constantly evolves in the same direction (EX: Horses)
Stabilizing Selection
Extremes are selected against, decreasing genetic diversity
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Eliminates the extremes
Disruptive selection
Extremes do better (in terms of physical characteristics) at surviving
Population Genetics
How frequency of alleles change due to population change
Migration (Gene flow)
The movement of alleles from one population to another as a result of interbreeding
Genetic drift
A change of allele frequencies as a consequence of random changes in population size
