BSC2010-Exam 3 (Non-cumulative study set) UF

Evolution is genetic change across generations of a population

Individuals do not evolve; populations do

Population

A group of individuals of a single species that live and interbreed in a particular geographic area at the same time

Evolution affects the genetic makeup of populations over time. What are the 5 processes that allows evolution to occur?

Natural selection, mutation, gene flow, genetic drift, and nonrandom mating

Mutation

Any change in the nucleotide sequences of an organism's DNA

Population Bottleneck

Form of genetic drift in which a population becomes extremely small; may lead to differences in allele frequencies and a loss in genetic variability

Founder Effect

Genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of that of the original population

Genetic Structure

The frequencies of different alleles at each locus and the frequencies of different genotypes in a Mendelian population

Fitness

Ability of an organism to survive and reproduce in its environment and contribute a phenotype compared to other phenotypes

Frequency-dependent Selection

Selection in which the fitness of a phenotype depends on how common the phenotype is in a population

Microevolution

Change in allele frequencies in a population over generations

Macroevolution

The broad pattern of evolution above the species level

Homologous

Any features shared by two or more species that have been inherited from a common ancestor

Lineage Species Concept

An ancestor-descendant series of populations followed over time.

Taxon

Any group of species that we designate with a name

Clade

Any taxon that consists of all the evolutionary descendants of a common ancestor

Sister Species

Two species that are each other's closest relatives

Sister Clades

Any two clades that are each other's closest relatives

Systematics

The study and classification of biodiversity

Synapomorphies

Derived traits that are shared among a group of organisms and are also viewed as evidence of the common ancestry of the group

Convergent Evolution

Superficially similar traits may evolve independently in different lineages, a phenomenon

Analogous Characters

Functionally similar structures that have independent evolutionary origins

Evolutionary Reversal

A character may revert from a derived state back to an ancestral state in an event

Homoplastic Traits/Homoplasies

Similar traits generated by convergent evolution and evolutionary reversals

Ancestral Trait

The trait originally present in the ancestor of a given group; may be retained or changed in the descendants of that ancestor

Derived Trait

New feature that had not appeared in common ancestors

Ingroup

The group of organisms of primary interest in a phylogenetic study

Outgroup

A species or group that is closely related to the ingroup but is known to be phylogenetically outside it. A point of reference for the ingroup

Parsimony Principle

States that the preferred explanation of observed data is the simplest explanation

Morhpology

The presence, size, shape, and other attributes of body parts

Maximum Likelihood Method

The method will identify the tree that most likely produced the observed data, given the assumed model of evolutionary change

Molecular Clock Hypothesis

Rates of molecular change are constant enough to predict timing of evolutionary divergence

Binomial Nomenclature

A system for giving each organism a two-word scientific name that consists of the genus name followed by the species name that allows scientists throughout the world to refer unambiguously to the same organisms by the same names.

Monophyletic

Pertaining to a group of taxa that consists of a common ancestor and all of its descendants. It is equivalent to a clade.

Polyphyletic

Pertaining to a group of taxa derived from two or more different ancestors.

Paraphyletic

Pertaining to a group of taxa that consists of a common ancestor and some, but not all, of its descendants.

Genome

the full set of genes it contains, as well as any noncoding regions of the DNA (or in the case of some viruses, RNA).

Pseudogenes

Copies of genes that have accumulated mutations over a long time and no longer produce functional proteins.

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.

Muller's Rachet

The accumulation of deleterious mutations in lineages that lack genetic recombination.

Gene Family

A group of homologous genes with related functions.

Maternal Effect Genes

Determine the anterior-posterior axis and induce three classes of segmentation genes

Segmentation Genes

Determine the boundaries and polarity of each of the segments.

Hox Genes

Determine what organ will be made at a given location and define the role of each segment.

Gap Genes

Organize several broad areas along the anterior-posterior axis and regulate...

Pair Rule Genes

Refine the segment locations and regulate...

Segment Polarity Genes

Determine the boundaries and anterior-posterior organization of the individual segments.

Genetic Toolkit

The regulatory genes that govern developmental processes that have been highly conserved throughout evolution.

Genetic Switches

Control how the toolkit is used, by turning genes on or off, or regulating the degree and timing of gene expression.

Heterometry

Differences in the amount of gene expression.

Heterochrony

Evolutionary change in the timing of gene expression.

Heterotropy

Evolutionary change in the physical location in the body of a developmental process (Spatial differences in gene expression).

In vitro evolution

New molecules are produced in the laboratory to perform novel and useful functions.

Polymorphism

The existence of two or more forms of individuals within the same animal species (DisruptiveSelection)

Clinal Variation

Gradual change in the phenotype of a species over a geographic gradient.

Monomorphic

Only one allele at a locus, frequency = 1; the allele is fixed.

Polymorphic

More than one allele at a locus.

Qualitative Traits

Influenced by alleles at one locus; often discrete qualities (black versus white).

Quantitative Traits

Influenced by alleles at more than one locus; likely to show continuous variation (body size of individuals).

Species

Groups of organisms that share a suite of genetic and morphological attributes, and are reproductively isolated from other such groups.

Speciation

The divergence of biological lineages and the emergence of reproductive isolation between lineages.

Cryptic Species

Two or more species that are morphologically indistinguishable but do not interbreed.

Reproductive Isolation

Two groups of organisms can no longer exchange genes.

Independent Evolutionary Lineage

A separate branch on the tree of life.

Biological Species Concept

Species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups.

Incipient Species

Populations that are in the process of diverging to the point of speciation but still have the potential to interbreed.

Allopatric Speciation

Speciation that results when a population is divided by a physical barrier.

Sympatric Speciation

Speciation without physical isolation.

Polyploidy

The duplication of the sets of chromosomes within individuals.

Prezygotic Isolating Mechanisms

Mechanisms that prevent hybridization from occurring.

Postzygotic Isolating Mechanisms

Mechanisms that reduce the fitness of hybrid offspring.

Allopolyploidy

Combining chromosomes of two different species.

Autopolyploidy

An individual that has more than two chromosome sets that are all derived from a single species.

Evolutionary Radiation

Proliferation of many species from a single ancestor.

Adaptive Radiation

Evolution from a common ancestor of many species adapted to diverse environments.

Crypsis

A defense against predators in which prey species have a shape or coloration that provides camouflage and allows them to avoid detection. (The ability of an animal to avoid observation or detection by predators).

Anisogamy

Refers to a difference in gamete size in males and females. Eggs large and costly, sperm small and cheap