Review Flashcards

Flashcards to review lecture notes.

What drives evolution, according to the lecture notes?

Mutations in genetic material (genomes).

What is a genome?

An entire set of data from an organism.

What percentage of the human genome is comprised of exons?

1.5%

What are transposable genetic elements?

Jumping genes that can introduce variance, creates mutations

What are transposons?

Mobile genetic elements that can move within a genome, potentially disrupting gene function and causing mutations.

What are retrotransposons?

Mobile genetic elements that can jump within a genome by copying themselves into new locations via an RNA intermediate.

What was the aim of the Human Genome Project (1990-2003)?

To cure various diseases through the study of the complete nucleotide sequence of each chromosome.

What is the Whole Genome Shot-Gun Approach?

To sequence an organism’s genome rapidly by breaking it up into smaller fragments and sequencing them individually to later order them with computer software

What is bioinformatics?

The use of technology to store, sort, and analyze genomic data.

What is Systems Biology?

The study of how different components within a living organism (genes, proteins, cells, etc.) interact with each other as a complex network to produce emergent properties and functions; how genes and proteins relate to one another to regulate the biological system.

What is a proteome?

The entire set of proteins expressed by a cell or tissue.

What is proteomics?

The study of large sets of proteins and their properties.

What is gene density?

The number of genes found along a megabase stretch of DNA.

What is exon skipping?

A common method of alternative RNA splicing

What are 3 methods of genetic modification?

Rearrangement of genes, Duplication of genes (errors in meiosis), Mutation of genes

Who discovered mobile genetic elements?

Barbara McClinktock

What is reverse transcriptase?

An enzyme that produces a complementary DNA strand from an RNA template strand.

What is nondisjunction?

The failure of chromosomes to separate properly during cell division (in this case, meiosis), resulting in daughter cells with an abnormal number of chromosomes.

What is polyploidy?

The condition of having more than two complete sets of chromosomes.

What is the definition of evolution presented in the lecture?

Descent with modification, reflects changes in genetic composition of a population over time.

Who created Scala Naturae and what is it?

Aristotle - ladder of creation with best species at the top and lower forms at the bottom, did not support evolution (permanence)

Who created Linnaean Taxonomy?

Carl von Linne

Who came up with the Principle of Gradualism?

Hutton - profound geologic changes were cumulative, slow and constant changes added up to create geography

What is Lamarck's Hypothesis of Evolution?

Evolution is driven by need/use; acquired characteristics are heritable (evolution is not over generations, changes are made by need and in a lifetime)

Who established extinction as a phenomena?

Curvier

Who came up with the Theory of Uniformitarianism?

Lyell - the scientific principle that the same natural processes observed today have always operated thoughts earth’s history (no change in geological processes throughout earth’s history)

What is Wallace known for?

Hypothesis of Natural Selection, Father of biogeography, had similar findings as Darwin, just less detailed

What evolves in Darwin's theory, populations or individuals?

Populations, not individuals, evolve.

What are three sources of support for evolution?

Direct observation of natural selection, Fossil Records, Homology, Biogeography

What is microevolution?

A change in allele frequencies in a population over time.

What is the particulate hypothesis of inheritance?

parents pass on discrete heritable traits (genes) to offspring

What prevents the elimination of recessive alleles via selection?

Balanced Polymorphisms

What are the three main sources of genetic variation?

Mutations, Gene Duplication, Sexual Reproduction

What is population genetics?

Describes the genetic composition of a population and how it changes over time.

What is the Hardy-Weinberg Equilibrium Principle?

A theoretical concept stating that in a population, allele and genotype frequencies will remain constant from generation to generation if there are no evolutionary influences

What are the five conditions for Hardy-Weinberg Equilibrium?

Random Mating, Large Population Size, No Mutations, No Natural Selection, No Gene Flow

What are the three alterations that occur in allele frequencies?

Natural selection, genetic drift, and gene flow

What is genetic drift?

A mechanism of evolution where the frequency of alleles in a population changes randomly over time due to chance events (random loss of alleles)

What is the founder effect?

A genetic phenomenon that occurs when a small group of individuals break off from a large population and establish a new colony.

What is the bottleneck effect?

A dramatic reduction in population size due to a catastrophic event.

What is gene flow?

Occurs when individuals or their gametes enter or leave a population, causes changes in allele frequencies (usually a reduction in variation).

What are the three ways natural selection alters gene frequency?

Directional Selection, Disruptive Selection, Stabilizing Selection

What is sexual dimorphism?

Different characteristics in males and females.

What is intrasexual selection?

Direct competition among individuals of one sex (usually males) for mates of the opposite sex in which dominance is determined, usually a ritual or display

What is intersexual selection?

An organism (usually female) has the choice of a mate of the opposite gender, picks are usually made based on which individual will offer fitness advantage

What is the Good Genes Hypothesis?

The idea that females will pick males based on phenotypic traits that act as honest indicators of a male’s genetic qualities.

Does natural selection create new genes?

Natural selection NEVER creates new genes. It just amplifies advantageous genes.

What is speciation?

The evolutionary process where a single population splits into two or more distinct species, becoming reproductively isolated from each other; a source of biodiversity, focal point of evolutionary theory

What is allopatric speciation?

A mode of speciation where a population is divided into two or more geographically isolated groups by a physical barrier.

What is sympatric speciation?

The evolution of a new species from a single ancestral population without any geographic separation; can be the result of habitat differentiation, sexual selection, accessibility to different resources.

What is autopolyploidy?

A genetic disorder in same species fertilization when a cell or organism has an abnormal number of chromosomes; results in an inability to breed with parent population

What is allopolyploid?

Fertilization between two different species; usually results in sterile hybrids and/or new species

What is a prezygotic barrier?

A reproductive barrier that occurs before the formation of a zygote, such as habitat isolation, temporal isolation, behavioral isolation, mechanical isolation, and gametic isolation.

What is a postzygotic barrier?

A reproductive barrier that occurs after the formation of a zygote, such as reduced hybrid viability, reduced hybrid fertility, and hybrid breakdown.

Define microevolution.

Small-scale evolutionary changes (changes in allele frequency) that occur within a population over a short period of time

Define macroevolution.

Large-scale evolutionary changes over longer periods of time; series of speciation events

What is the biological species concept?

A group of organisms that can interbreed and produce fertile, viable offspring.

What is a hybrid zone?

A geographic area where two closely related species or subspecies cause meet and reproduce, forming hybrids.

What are the 3 possible outcomes for hybrids?

Reinforcement, fusion, or stability.

What is reinforcement in the context of hybrid zones?

Strengthen reproductive barriers, occurs if hybrids are less fit than parent species, prezygotic reproductive barriers increase, resulting in stronger sympatric than allopatric species

What is fusion in the context of hybrid zones?

Weakens reproductive barriers, occurs if hybrid and parent species have similar fitness, gene flow between hybrid and parent population allow for fusion into a single species

What is stability in the context of hybrid zones?

Status quo remains, hybridization continues, hybrids have strong fitness but little gene flow between hybrids and parents occur

Define macroevolution in the context of the history of life on earth.

Large-scale evolutionary changes that occur over long periods of time, resulting in the formation of new species or higher taxonomic groups; pattern of evolution above the species level

What was the Miller/Urey experiment purposed to test?

Test the hypothesis that organic molecules, like amino acids, could be formed abiotically from simple inorganic compounds under conditions thought to exist on early earth.

What are stromatolites?

Earliest fossil evidence of life (cyanobacterial biofilm).

What are sedimentary rocks?

A type of rock formed by the accumulation and consolidation of mineral and organic particles at the Earth’s surface, typically deposited in distinct layers; most abundant source of fossils

What are strata?

The distinct layers in sedimentary rock, used to determine the relative order of life

What is the Oxygen Revolution?

A significant period in Earth’s history when the atmospheric oxygen levels drastically increased due to the emergence of cyanobacteria (photosynthetic organisms) that used CO2 and sunlight to produce O2; led to changes in organisms

What is serial endosymbiosis?

The process in which a cell engulfs another cell, and the engulfed cell becomes an organelle within the host cell.

What is the Cambrian Explosion?

The sudden appearance of fossils resembling all modern animal phyla, first evidence of

What is plate tectonics?

Continental drifts (the constant movement of plates) cause extreme changes in habitat or climate, forcing organisms to adapt, move, or become extinct > allopatric speciation due to movement of land.

What is biogeography?

Explains the geographic distribution of extinct organisms and current distribution of extant organisms

What is Pangaea?

Supercontinent (335 MYA)

What effect did spike in CO2 have in the Permian Mass Extinction?

Extreme volcanic activity > global warming > bloom in anaerobes that released hydrogen sulfide and bacteria; reduction of O2

What characterized the Cretaceous Mass Extinction?

Asteroid (contained iridium) hits earth > debris blocked the sun, changing habitats (due to hit) and climate (blocking of sun)

What is adaptive radiation?

The rapid evolution of diverse adapted species from a common ancestor

What is heterochrony?

An evolutionary mechanism where a change in the timing or rate of a developmental process in an organism occurs compared to its ancestors, leading to differences in the size, shape, and characteristics of certain features or organs between the descendant and ancestral organism

What is paedomorphosis?

An evolutionary process during which the rate of an organism’s reproductive development either accelerates or halts (organs remain “juvenile” even during adulthood); a type of heterochrony

What are homeotic genes?

A group of genes that control the development of specific body segments or structures

What are Hox genes?

Controls positional information during embryonic development

What is exaptation?

A trait or feature of an organism that evolved for one function but later came to serve a different, new function through natural selection

What is phylogeny?

The evolutionary history and relationships between groups of organisms; inferred from morphological and molecular data

What is homology?

The similarity in anatomical structures or genetic sequences between different organisms due to shared ancestry (ex. Forelimbs of mammals); primary classification criterion to infer phylogeny

What is analogy?

Similarity in function of structures of different organisms due to convergent evolution, no shared ancestry (ex. Bird and bat wings)

What is a rooted tree?

A type of tree that includes the most recent common ancestor of all taxa in one tree

What is a branch point (dichotomy)?

The point of divergence of two evolutionary lineages from a common ancestor; can be points of rotation

What are sister taxa?

Groups of organisms that share an immediate common ancestor

What is a basal taxon?

Lineage that diverges early in evolutionary history from other groups on the tree

What is a polytomy?

Unresolved lineage, may have three or more parallel branches together

What are extant species?

Species that are present, located at the ends of branches

What is systematics?

The scientific study of the diversity of life on earth, focusing on classifying organisms and determining their evolutionary relationships with each other; used to construct phylogenetic trees

What is taxonomy?

Determines the naming and classification of organisms

What are the three domains of life?

Bacteria, eukarya, archaea

What are cladograms?

A diagram that visually represents the evolutionary relationships between organisms based on characteristics

What are Characters (traits, characteristics)?

Any feature that defines a particular taxon

What is a shared derived character?

A specific trait that evolved within a particular lineage and is shared by all organisms within the taxon/clade, distinguishing them from other groups that lack this trait

What is an ingroup?

A species or group of species with shared derived character

What is an outgroup?

Species of group of species that diverged before ingroup, does not have shared derived characteristics with ingroup but closely related to ingroup

What is a shared ancestral character?

A trait or characteristic that is present in a common ancestor or a group of organisms; shared by all members of a taxon

What is a clade?

A group consisting of a common ancestor and all its descendants