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1116 Evol, Ecol, Biodiv
Midterm cuecards
194
Biology
Undergraduate 1
02/05/2013

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Term
Proterozoic
Definition

Soft-bodied animals

1200-542 mya

Term
Paleozoic
Definition

Origin of arthropods, vertebrates, land plants

542-251 mya

Term
Mesozoic
Definition

dinosaurs, birds, mammals

251-65.5 mya

Term
Cenozoic
Definition

Primates

65.5-0 mya

Term
Carolus Linnaeus
Definition
Invented the system of binomial nomenclature
Term
Taxonomy
Definition
The branch of biology concerned with classifying organisms
Term
Georges Cuvier
Definition

Plaeontology (study of fossils)

Catastrophism (each boundary between strata represents a catastrophe)

Term
Thomas Malthus
Definition
Noted the potential for human population to increase faster than food supplies and other resources
Term
Three necessary conditions for adaptation by natural selection
Definition

1. Individuals must vary in reproductive success

2. Some variation in the trait must be heritable

The trait mustbe correlated with reproductive success

Term
Homology
Definition
Similarity resulting from common ancestry
Term
Homologous Structures
Definition
anatomical resemblances that represent variations on a strutural theme present in a common ancestor
Term
Vestigial Structures
Definition
remnants of features that served important functions in the organism's ancestors
Term
What are evolutionary trees?
Definition
Hypothesus about the relationships among different groups
Term
When so analogous traits arise?
Definition
groups independently adapt to similar environments in similar ways
Term
Convergent evolution
Definition
the evolution of similar or analogous features in distantly related groups
Term
Charles Lyell
Definition
Proposed the principle of uniformitarianism (states that the mechaisms of change are constant over time)
Term
Lamarck
Definition
Hypothesized that specieis evolve through use and disuse of body parts and the ingeritance of acquired characterstics
Term
Wallace
Definition
Had a theory of natural selection similar to Darwin's
Term
Microevolution
Definition
A change in allele frequencies in a population over generations
Term
Average heterozygosity
Definition
Measure the average percent of loci that are heterozygous in a population
Term
Nucleotide variability
Definition
Measured by comparing the DNA sequences of pairs of individuals
Term
Point mutation
Definition
Change in one base in a gene
Term

Do prokaryotes or viruses have higher mutation rates?

 

Definition
Viruses
Term
Population
Definition
Localized group of individuals capable of interbreeding and producing fertile
Term
Gene Pool
Definition
Consists of all the alleles for all loci in a population
Term
How is a locus fixed?
Definition
If all individuals in a population are homozygous for the same allele
Term
What does the Hardy-Weinberg principle describe?
Definition
A population that is NOT evolving
Term
What is the value of the Hardy-Weinberg theorem?
Definition
Allows us to determine the cause of changes in gene frecquencies
Term
Five conditions for non-evolving populations
Definition
No mutations, random mating, no natural selection, extremely large population size, no gene flow
Term
Genetic Drift
Definition
Random changes in allele frequencies
Term
Founder Effect
Definition
When a few individuals become isolated from a larger population (allele frequencies are different)
Term
The bottleneck effect
Definition
The sudden reduction in population size due to a change in the environment
Term
Bottleneck Effet: what happens to the resulting gene pool?
Definition
May no longer be refletive of the original population's gene pool
Term
Effects of Genetic Drift
Definition

1. Is significant in small populations

2. Causes allele frecquencies to change at random

3. Can lead to a loss of genetic variationwithin populations

4. Can cause harmful alleles to become fixed

Term
Gene Flow
Definition
Movement of alleles among populations
Term
Relative Fitness
Definition
The contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals
Term
Directional Selection
Definition
Favors individuals at one end of the phenotypic range
Term
Disruptive Selection
Definition
Favors individuals at both extremes of the phenotypic range
Term
Stabilizing Selection
Definition
Favors intermediate variants and acts against extreme phenotypes
Term
When does adaptive evolution occur
Definition
As the match between an organism and it's environment increases
Term
Sexual Dimorphism
Definition
Dinstinction between secondary secual characteristics of males and females
Term
Intrasexual Selection
Definition
Competition among individuals of one sex (often males) for mates of the opposite sex
Term
Intersexual Selection
Definition
Often called mate choice, occurs when individuals of one sex (usually females) are choosy in selecting their mates
Term
How does diploidy maintain genetic variation?
Definition
In the form of hidden recessive alleles
Term
Balancing Selection
Definition
Occurs when natural seelction maintains stable frecquencies of two or more phenotypic forms in a population
Term

Heterozygous Advantage

 

Definition
When heterozygotes have a higher fitness than do both homozygotes
Term
Frequency-Dependent Selection
Definition
The fitness of a phenotype declines if it becomes too common in the population
Term
In frequency-dependent selection, which phenotype is favored?
Definition
Whicher is less common in a population (e.g. scale-eating cichlids)
Term
Neutral Variation
Definition
Genetic variation that appears to confer no selective advantage or disadvantage (e.g. variaiton in noncoding regions of DNA)
Term
4 Reasons why natural selection cannot fashion perfect organisms
Definition

1. Selection can act only on existing variations

2. Evolution is limited by historical constraints

3. Adaptations are often compromises

4. Chance, natural selection, and the environmet interact

Term
Microevolution
Definition
Consists of adaptations that evolve within a population, confined to one gene pool
Term
Macroevolution
Definition
Refers to evolutionary change above the species level
Term
Species
Definition
A group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring
Term
Reproductive Isolation
Definition
The existence of biologival factors that impede two species from producing viable, fertile offspring
Term
What is a problem of the biological species concept?
Definition
Cannot be applied to fossils or asexual organisms (including all prokaryotes)
Term
Morphological species concept
Definition
Defines a species by structural features
Term
Where do we run into problems with the morphological species concept?
Definition
With polymorphic species
Term
Ecological Species concept
Definition
View a species in temr of its ecological niche
Term
Phylogenetic species concept
Definition
Defines a species as the smallest group of individuals on a phylogenetic tree
Term
Two ways speciation occurs
Definition
Allopatric speciation, sympatric speciation
Term
Allopatric speciation
Definition
Gene flow is interrupted or reduced when a population is divided into geographically isolate subpopulations
Term
Repoductive isolation between populations generally increase as....
Definition
The distance between them increase
Term
Where deos sympatric speciation take place?
Definition
In geographically overlapping populations
Term
Polyploidy
Definition
The presence of extra sets of chromosomes due to accidents during cell division
Term
Autopolyploid
Definition
An individual with more than two chromosome sets, derived from one species
Term
Allopolyploid
Definition
Is a species with multiple sets of chromosomes derived from different species
Term
Is polyploidy more common in plants or animals?
Definition
Plants
Term
Even if contact is restored between two populations, they may not be able to reproduce because?
Definition
Reproductive isolation may have arose by natural selection, genetic drift, or sexual selection
Term
Sympatric speciation can result from
Definition
Polyploidy, natural selection, or sexual selection
Term
Hybrid zone
Definition
A region in which members of different species mate and produce hybrids
Term
Reinforcement of barriers occurs when...
Definition
Hybrids are less fit than the parent species
Term
Punctuated equilibrium
Definition
Periods of apparent stasis punctuated by sudden change
Term
Macroevolution
Definition
The cumulative effect of many speciation and extinction events
Term
When did the earth form?
Definition
4.6 billion years ago
Term
Protobionts
Definition
Aggregates of abiotically produced molecules surounded by a membrane or membrane-like structure
Term
The first genetic material was probably
Definition
RNA, not DNA
Term
Archaean eon
Definition
4.6 to 3.5 bya
Term
Proterozoic eon
Definition
2.5 bya to 542 mya
Term
Phanerozoic era
Definition
541 mya to present
Term
The oldest known fossils are
Definition
Stromatolites (3.5 billion years ago)
Term
What is the origin of mitochondria and plastids
Definition
Endosymbiotic: they lived in a host cell
Term
Date of the common ancestor of multicellular eukaryotes
Definition
1.5 billion years ago
Term
The first fossils of many animal phyla date to
Definition
Early cmabrian or late proterozoic
Term
DNA analyses suggest what about many animal phyla
Definition
That they diverged before the cambrian explosion
Term
When did fungi, plants, and animals begin to colonize land
Definition
500 million years ago
Term
The permian extincction was the mass extinction of 96% of waht
Definition
Marine animal species
Term
How many mass extinctions has there been?
Definition
5
Term
Heterochrony
Definition
An evolutionary change in the rate or timing of developmental events
Term
Homeotic genes
Definition
Determine such basic features as where wings and legs will develop on a bird or how a flower's parts are arranged
Term
Hox genes
Definition
A class of homeotic genes that provide information during development
Term
Evolution of vertebrates from invertebrate animals was associated with alterations in
Definition
Hox genes
Term
Specific changes in the Ubx gene can
Definition
Turn off leg development
Term
Phylogeny
Definition
The evolutionary history of a species or group of related species
Term
Systematics
Definition
Classifies organisms and determines their evolutionary relationship using fossil, molecular, and genetic data to infer evolutionary relationships
Term
Taxonomy
Definition
The ordered division and naming of organisms
Term
Taxon
Definition
a taxonomic unit at any level of hierarchy
Term
What does the PhyloCode recognize?
Definition
Only groups that include a common ancestor and all it's descendants
Term
What does a phylogenetic tree represent
Definition
A hypothesis about evolutionary relationships
Term
What do branch points represent
Definition
The divergence of two species
Term
Sister taxa
Definition
Groups that hare an immediate common ancestor
Term
Rooted tree
Definition
Includes a branch to represent the last common ancestor of all taxa in the tree
Term
Polytomy
Definition
A branch from which more than two groups emerge
Term
Phylogenetic trees DO NOT indicate
Definition
When species evolved or how much genetic change occurred in a lineage
Term
Homology
Definition
Similarity due to shared ancestry
Term
Analogy
Definition
Similarity due to convergent evolution
Term
When does convergent evolution occur?
Definition
When similar environmental pressures and natural selection produce similar adaptations in organisms from different evolutionary lineages
Term
Homoplasies
Definition
Analogous structures or molecular sequences that evolved independently
Term
The more complec two similar structures are, the more likely it is that they are
Definition
Homologous
Term
Cladistics
Definition
Groups organisms by common descent
Term
Clade
Definition
A group of species that include an ancestral species and all it's descendants
Term
A valid clade is monophyletic, which signifies that
Definition
It consists of the ancestor species and all its descendants
Term
A paraphyletic groups consists of
Definition
An ancestral species and some, but not all, of the descendants
Term
A polyphletic grouping consists of
Definition
Various species that lack a common ancestor
Term
Why are blackbirds of the genus Agelaius poluphyletic?
Definition
Becuase they are ecologically and behaviourally similar; this is due to convergent evolution, not recent common ancestry
Term
What kind of characteristic if the four-limbed condition of mammals?
Definition
Ancestral
Term
What kind of a characteristic if the fur/hair of mammals?
Definition
Derived
Term
Shared ancestral character
Definition
A character that originiated in an ancestor of the taxon
Term
Shared derived character
Definition
An evolutionary novelty unique to a particular clade
Term
Outgroup
Definition
A species or group of species that is closely related to the ingroup
Term
Ingroup
Definition
The various species being studied
Term
The branch length in phylogenetic trees can represent what?
Definition
The number of genetic changes that have taken place in a particular DNA sequence in that lineage or chronological time
Term
Maximum parsimony
Definition
Assumes that the tree that requires that fewest evolutionary events (appearances of shared derived characters) is the most likely
Term
Maximum likelihood
Definition
Given certain rules about how DNA changes over time, a tree can be found that reflects the most likely sequence of evolutionary events
Term
Phylogenetic bracketing
Definition
Allows us to predict features of an ancestor from features of its descendants
Term
Because mtDNA evolves rapidly, what can it be used to explore?
Definition
Recent evolutionary events
Term
Because DNA that codes for rRNA changes relatively slowly, what is it useful for?
Definition
Investigating branching points hundreds of millions of years ago
Term
Comparing nucleic acids or other molecules to infer relatedness is a valuable tool for
Definition
Tracing organisms' evolutionary history
Term
What does gene duplication do?
Definition
It increases the number of genes in the genome and provides more opportunities for evolutionary changes
Term
Orthologous genes
Definition
Found in a single copy in the genome and are homologous between species
Term
Paralogous genes
Definition
Result from gene duplication, so are found in more than one copy in the genome (e.g. chorionic gonadotropin genes found in humans)
Term
Molecular clock
Definition
Uses constant rates of evolution in some genes to estimate the absolute time of evolutionary change
Term
In orthologous genes, nucleotide substitutions are proportional to
Definition
The time since they last shared a common ancestor
Term
In papalogous genes, nucleotide substitutions are proportional to
Definition
The time since the genes became duplicated
Term
Neutral theory
Definition
States that much evolutionary change in genes and proteins has no effect on fitness and therefore is not influenced by Darwinian selection
Term
Phylogenetic analysis shows that HIV is descended from
Definition
Viruses that infect chimpanzees and other primates
Term
Are eukaryotes more closely related to archea or bacteria?
Definition
Archea
Term
Horizontal gene transfer
Definition
The movement of genes from one genome to another
Term
What does hoirzonatal gene transwer complicate?
Definition
Efforts to build a tree of life
Term
What are eukaryote cell walls made of?
Definition
Cellulose or chitin
Term
What are bacterial cells walls made of?
Definition
Peptidoglycan
Term
Antibiotics like penicillin target what?
Definition
Peptidogylcan and damage basterial cell walls
Term
Taxis
Definition
The ability to move toward or away from certain stimuli
Term
Why do prokaryotes evolve rapidly?
Definition
Because of their short generation times
Term
Three factors that contribute to the genetic variation of prokaryotes
Definition
Rapid reproduction, mutation, genetic recombination
Term
Transformation
Definition
Incorporating foreign DNA from the surrounding environment
Term
Transduction
Definition
The movement of genes between bacteria by bacteriophages
Term
Conjugation
Definition
Process where genetic material is transferred between bacterial cells
Term
Where to phototrophs obtain energy?
Definition
The light
Term
Where do chemotrophs obtain energy?
Definition
From chemicals
Term
What do autotrophs require?
Definition
COas a carbon source
Term
What do heterotrophs require?
Definition
An organic nutrient to make organic compounds
Term
Obligate aerobes
Definition
required Ofor cellular respiration
Term
Obligate anaerobes
Definition
Are poisoned by O2 and use germentation or anaerobic respiration
Term
Facultative anaerobes
Definition
Can survive with or without O2
Term
Nitrogen fixation
Definition
Conversion of atmospheric nitrogen to ammonia
Term
Cooperation between prokaryotes allows
Definition
Them to use environment resources they could not use as individual cells (heterocytes and photosynthetic cells in cyanobacterium)
Term
Extremophiles
Definition
Archea that live in extreme environments
Term
Extreme halophiles
Definition
Live in highly saline environments
Term
Extreme thermophiles
Definition
Thrive in very hot environments
Term
Methanogens
Definition
Live in swamps and marches and produce mathane as a waste product
Term
Helicobacter pylori
Definition
A proteobacteria that infects about half the world's population and causes stomach ulcers and stomach cancer
Term
Chlamydias
Definition
Parasites that live within animal cells and cause blindness and nongonococcal urethritis
Term
Spirochetes
Definition
Bacteria that are helical heterotrophs and cause syphillis and lyme disease
Term
Prokaryotes play a major role in
Definition
The recylcing of chemical elements between the living and nonliving components of ecosystems
Term
Chemoheterotrophic prokaryotes function as
Definition
Decomposers
Term
Symbiosis
Definition
An ecological relationship in which two species lie in close contact
Term
Mutualism
Definition
Both symbiotic organisms benefit
Term
Commensalism
Definition
One organism benefits while neither harming nor helping the other in any significant way
Term
Parasitism
Definition
An organism called parasite harms but does not kill its host
Term
Exotoxins
Definition
Cause disease even in the prokaryotes that produce them are not present
Term
Endotoxins
Definition
Released only when bacteria die and their cell walls break down
Term
Bioremediation
Definition
The use of organisms to remove pollutants from the environment
Term
Principle agents in bioremediation
Definition
Prokaryotes
Term
Five supergroups of Eukaryotes
Definition
Excavata, Chromalveolata, Rhizaria, Archaeplastida, Unikonta
Term
Excavata is characterized by
Definition
Cytoskeleton
Term
Diplomonads
Definition
Modified mitochondia called mitosomes, derive energy anaerobically, have two equal sized nuclei and multiple flagella, are often parasites
Term
Parabasalids
Definition
Reduced hydrogenosomes that generate some energy anaeobically
Term
Euglenozoans
Definition
Spiral or crystalline rod of unknown function inside their flagella (includes kinetoplastics and euglenids)
Term
Kinetoplastics
Definition
Have a single mitochondrion with an organized mass of DNA called a kinetoplast
Term
Alveolates
Definition
Have membrane bounded savs called alveoli
Term
Apicomplexans
Definition
Parasites of animals and some cause serious human diseases
Term
Plasmodium
Definition
The parasite that causes malaria
Term
Brown algae
Definition
Thr largest and most complex algae (seaweeds)
Term
Alternation of generations
Definition
The alternation of multicellular haploid and diploid forms
Term
What was responsible for the Irish potato famine?
Definition
A water mold
Term
What are the closest relatives of land plants?
Definition
Red algae and green algae
Term
When were plants on land
Definition
At least 475 millions years ago
Term
Gymnosperms
Definition
"Naked seed" plants, including conifers
Term
Angiosperms
Definition
Flowering plants
Term
Seed
Definition
Embryo and nurtients surrounded by a protective coat
Term
During the first 100 millions years of plant evolution, what were the prevalent vegatation?
Definition
Bryophytes
Term
When did vascular plants begin to diversify
Definition
During the devonian and carboniferous periods
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