Substitution rates
________ are higher at nucleotide positions that do not change the amino acid being expressed.
Speciation
________ is what leads to the branching events on the tree of life, and is the process that results in the millions of species that constitute biodiversity.
Hybridization
________ leads to the exchange of many genes among recently separated lineages of plants.
Hox genes
________ determine what organ will be made at a given location.
Pair rule genes
________ divide the embryo into units of two segments each.
acid position
If a given amino ________ is under purifying selection, then the observed rate of synonymous substitutions is expected to be much higher than the rate of nonsynonymous substitutions in the corresponding sequences.
Nonsynonymous
________ are likely to be deletrious.
small populations
In species with ________, the effects of genetic drift can overwhelm selection against noncoding sequences that have small deleterious consequences.
Maternal effect genes
________ set up the major axes (anterior- posterior and dorsal- ventral) of the embryo.
homeodomain
The ________ recognizes and binds to a specific DNA sequence in the promoters of its target genes,"turning on "the formation of specific structures.
Hox genes
________ encode a family of transcription factors that are expressed in different combinations along the length of the embryo, and help determine cell fates within each segment.
Synonymous Substitution
A change of one nucleotide in a sequence to another when that change does not affect the amino acid specified; aka silent
NonSynonymous Substitution
A change in a gene from one nucleotide to another that changes the amino acid specified by the corresponding codon; missense & nonsense are included
Pseudogenes
A DNA segment that is homologous to a functional gene but is not expressed because of changes to its sequence or changes to its location in the genome
Neutral Theory
A view of molecular evolution that postulates that most mutations do not affect the amino acid being coded for, and that such mutations accumulate in a population at rates driven by genetic drift and mutation rates
Positive selection
Natural selection that acts to establish a trait that enhances survival in a population
Purifying selection
The elimination by natural selection of detrimental characters from a population
Convergent evolution
Independent changes to the same state or trait in two or more groups of organisms
Mullers Ratchet
The accumulation-"ratcheting up"-of deleterious mutations in the nonrecombining genomes of asexual species
Lateral gene transfer
The transfer of individual genes, organelles, or fragments of genomes from one species to another, common among bacteria and archaea
Gene duplication
A way that genomes can acquire new functions
Morphogens
A diffusible substance whose concentration gradient determines a developmental pattern in animals and plants
Homoeotic mutations
Mutation in a homeotic gene that results in the formation of a different organ than that normally made by a region of the embryo
Homeobox
A 180-base-pair segment of DNA found in certain homeotic genes; regulates the expression of other genes and thus controls large-scale developmental processes
Homeodomain
A 60-amino acid sequence within the homeobox that regulates the expression of other genes and through this regulation controls large-scale developmental processes
Homologous
In evolutionary biology, one of two or more features in different species that are similar by reason of descent from a common ancestor
Genetic toolkit
A set of developmental genes and proteins that is common to most animals and is hypothesized to be responsible for the evolution of their differing developmental pathways
Genetic switches
Mechanisms that control how the genetic toolkit is used, such as promoters and the transcription factors that bind them; The signal cascades that converge on and operate these switches determine when and where genes will be turned on and off
Heterometry
Alteration in the level of gene expression, and thus in the amount of protein produced, during development, contributing to the evolution of different phenotypes in the adult
Heterochrony
Alteration in the timing of developmental events, leading to different results in the adult organism
Heterotopy
Spatial differences in gene expression during development, controlled by developmental regulatory genes and contributing to the evolution of distinctive adult phenotypes
In Vitro Evolution
A method based on natural molecular evolution that uses artificial selection in the laboratory to rapidly produce molecules with novel enzymatic and binding functions
Heterometry
________: Alteration in the level of gene expression, and thus in the amount of protein produced, during development, contributing to the evolution of different phenotypes in the adult.
Pseudogenes
________: A DNA segment that is homologous to a functional gene but is not expressed because of changes to its sequence or changes to its location in the genome.
Homeodomain
________: A 60- amino acid sequence within the homeobox that regulates the expression of other genes and through this regulation controls large- scale developmental processes.
Morphogens
________: A diffusible substance whose concentration gradient determines a developmental pattern in animals and plants.
Convergent evolution
________: Independent changes to the same state or trait in two or more groups of organisms.
Homeobox
________: A 180- base- pair segment of DNA found in certain homeotic genes; regulates the expression of other genes and thus controls large- scale developmental processes.
evolutionary biology
Homologous: In ________, one of two or more features in different species that are similar by reason of descent from a common ancestor.
Synonymous Substitution
________: A change of one nucleotide in a sequence to another when that change does not affect the amino acid specified; aka silent.
Heterotopy
________: Spatial differences in gene expression during development, controlled by developmental regulatory genes and contributing to the evolution of distinctive adult phenotypes.
Heterochrony
________: Alteration in the timing of developmental events, leading to different results in the adult organism.
Genetic toolkit
________: A set of developmental genes and proteins that is common to most animals and is hypothesized to be responsible for the evolution of their differing developmental pathways.
Mullers Ratchet
________: The accumulation "- ratcheting up- "of deleterious mutations in the nonrecombining genomes of asexual species.
Neutral Theory
________: A view of molecular evolution that postulates that most mutations do not affect the amino acid being coded for, and that such mutations accumulate in a population at rates driven by genetic drift and mutation rates.
Vitro Evolution
In ________: A method based on natural molecular evolution that uses artificial selection in the laboratory to rapidly produce molecules with novel enzymatic and binding functions.
natural selection
Purifying selection: The elimination by ________ of detrimental characters from a population.
NonSynonymous Substitution
________: A change in a gene from one nucleotide to another that changes the amino acid specified by the corresponding codon; missense & nonsense are included.