Biology 240

identification and classification of organisms following the rules of nomenclature

the study of the evolutionary history of a species or group of species

the study of phylogeny

study of biodiversity in an evolutionary context

two main characteristics of linnean system

species has a two part name

the second part of binomial system

groups species into broader taxonomic categories

species that appear closely related are grouped into the same genus

each taxonomic level is more comprehensive tahn the previous one

taxonomic unit at any level

3 main objectives of systematics

three ways systematics define characters and delimit species

are determined through observations and interpretations

alternate values for a character

microevolution is reflected in character state changes

organ, structure, size, color

tissue or cell type, ultrastructure

chemical pathways, enzymes

base pair sequence to protein sequence

patterns of development

classifying species into higher taxonomic categories based on overall similarity

overall similarity must be based on homologous characters not on analogous characters

similarity in characters resulting from common ansetry

similarity in characters resulting from convergent evolution

phylogenetic trees reflect the hierarchical classification of taxonomic groups nested within more inclusive groups

phylogeny is determined by a variety of evidence such as these 3

most systematics use _____ to analyze the data

a phylogenetic diagram is constructed from a series of dichotomies

a clade that consists of an ancestral species and all its descendants

groups that do not fit the definition of a monophyletic group definition are considered

a taxon that includes the ancestor and all of its descendants

a taxon that includes the ancestor and some but not all of its descendants

a taxon that includes species derived from more than one recent ancestor

apomorphic

pleisiomorphic

forelimbs of bats and birds are analogous adaptations because they both evolved for flight from forelimbs that were used for walking

similarities that are based on shared ancestry

presence of forelimbs in both birds and bats are an example of

the more homologous parts that two species share, the more closely related they are
the more complex two structures are the less likely that they evolved independently

is unique to a particular clade (synapomorphies)

is found not only in the clade being analyzed, but older clades too (sympleisiomorphies)

building a monophyletic phylogeny is based on use of

analyzing the taxonomic distribution of homologies enable us to identify the sequence in which derived characters evolved

presents the chronological sequence of branching during the evoluitionary history of a set of organisms

systematics can use cladograms to place species in the taxonomic hierarchy`

the principle of ______ helps systematists reconstruct phylogeny

a theory that nature should be the simplest explanation that is consistent with the facts

the evolution of the eukaryotic cell led to the development of several unique cell structures and processes such as these 6

these two things of prokaryotes imposes limits on the number of different metabolic activities that can be accomplished at one time

how does the small size of a prokaryote limit the number of metabolic activities

three trends of prokaryotes

the evolution of colonial prokaryotes trend

the evolution of complex communities of prokaryotes trend

compartmentalization of different functions within single cells trend

modification of the plasma membrane into specialized structure

endocytosis of prokaryotes that develop into symbiotic organelle

autogenic origin model suggests that

endosymbiotic origin model

these two structures possibly developed through invagination of the plasma membrane

become more complex and more numerous because of complex metabolism

evolved in response to making DNA more stable and easier to divide

these two evolved in response to extremem environmental conditions

in living eukaryotes today, the nuclear membrane is often attachted to the

where is the endoplasmic reticulum located

where did the mitochondria and chloroplast evolve from

serial endosymbiosis theory

proposed ancestors of mitochondria were

the proposed ancestors of chloroplasts were

the ancestors of mitochondria and chloroplasts  probably entered the host cell by

how could the heterotrophic host derive nourishment

in an increasingly aerobic world, an anaerobic host cell could benefit from what and by

serial endosymbiosis theory supposes that

6 lines of evidence for serial endosymbiosis

all eukaryotes have or have had mito

two lineages that lack mitochondria but have mito genes in their nuclear genome

chloroplast evolved after mitochondria however diversified into numerous lineages of

it is proposed that cilia and flagella evolved from

cilia and flagella aka

is a chimera of prokaryotic ancestors

the eukaryotic cell evolved by

origin of the new taxonomic groups

is the keystone process in the origination of diversity of higher

vary dictated by available data

the accumulation of changes associated with the transformation of one species into another

fossil record chronicles two patterns of speciation

branching evolution is the budding of one or more new species from a parent species

promotes biological diversity by increasing the number of species

the node of a phylogenic tree represents

three major species concept

morphological species concept emphasizes overall similarity

morphological species characterized by combinations of these 3 features

individuals with the similar overall morphologies belong to the same species

4 problems with the morphological species concept

a population or group whose members have the potential to interbreed with each other to produce viable offspring

set of populations in which genetic exchange is possible and genetically isolated from other populations

species are based on ______ not phyiscal similarity

4 problems with biological species

those who share a recent common ancestor belong to the same species

concept that emphasizes reproductive isolation

concept that emphasizes genetic relatedness

concept that emphasizes overall similarities

3 problems with evolutionary species concept

2 reproductive barriers

these 2 isolate the gene pools of biological species

impede mating between species or hinder fertilization of ova if members of different species attempt to mate

6 prezygotic barriers

two organisms that live in different geographic areas are unlikely to encounter each other to attempt mating

discrete populations

populations that occupy the same geographic area

two organisms that use different habitats even in the same geographic area are unlikely to encounter each other to even attempt meeting

example of habitat isolation

many species elaborate behaviors unique to a species to attract mates

behavioral isolation example

two species that breed during different times of day, different seasons, or different years cannot mix gametes

closely related species may attempt to mate but fail because they are anatomically incompatible and transfer of sperm is not possible

occurs when gametes of two species do not form a zygote because of incompatibilities preventing fusion or other mechanisms

prevent the hybrid zygote from developing into a viable fertile adult

offspring of a mating between two different species

genetic incompatibility between the two species may abort the
(hybrid inviability)

even if the hybrid offspring are vigorous,

hybrid inviability example

example of hybrid infertility

2 general modes of speciation are distinguished by the mechanism by which gene flow among populations is initially interrupted

geographic separation of populations restricts gene flow

speciation occurs in geographically overlapping populations when biological factors reduce gene flow

several geological processes can fragment a population into two or more isolated populations

due to allopatric speciation individuals may

likelihood of allopatric speciation increases when

a small isolated population is more likely to have its gene pool changed substantially by genetic drift and natural selection

very few small isolated populations will ______
most populations will ______

evolution of many diverse adapted species from a common ancestor

new species form when geographically isolated populations evolve reproductive barriers as a byproduct of genetic drift and natural selection to its new environment

new species arise within the range of the parent populations

sympatric speciation can result from a mutant condition

this mutant can reproduce with itself or with tetraploids (4n)

this ploidy cannot mate with diploids from the original populations

polyploidy individuals that occur when individuals are produced by the matings of two different species

polyploidy hybrids are fertile but cannot interbreed with either parent species
(hybrids are sterile)

example of polyploidy in agricultural products

evolutionary tree diagram assume that big changes occur as the accumulation of many small ones

sudden apparent appearance of species in the fossil record may reflect allopatric speciation

the tempo of speciation is not constant

punctuated equilibrium model
species undergo most morphological modifications when they first bod from their parent population

spurts of rapid evolutionary change followed by longer periods of stasis

a change over the generations in a populations allele frequency by genetic drift or NS

occurs when a populations genetic divergence from its ancestral population results in reproductive isolation

is the boundary between micro and macroevolution

evolutionary novelties can arise by gradual refinement of existing structures for new functions

example of exaptation

research that examines how slight genetic divergences can become magnified into major morphological differences between species

an evolutionary change in the rate or timing of developmental events

tracks how proportions of structures change due to different growth rates during development

evolution of morphology by modification of allometric growth is an example of

appears to be responsible for differences in the feet of tree dwelling and ground dwelling salamanders

rate of reproductive development accelerates compared to somatic development, then a sexually mature stage can retain juvenile structures

4 reasons species become extinct

this mass extinction claimed 90% of all marine species

permian mass extinction

doomed half of marine species and many families of terrestrial plants and animals

cretaceous mass extinction

event that defines the boundary between the mesozoic and cenozoic era

2 hypothesis for the mechanisms behind the cretaceous mass extinction

are what we see (data)

are mechanisms that responsible for those patterns

the first scientist to propose a system of evolution

noticed that fossils became more complex in more recent rock strata

believed there was an initial drive towards complexity

believed evolution was based on two principles

two principles evolution was based on

organs/structure became stronger/weaker with use/disuse and are passed in to offspring

unconscious striving in the lower creatures to become more complex and human

said species are fixed and do not change

a philosophy of science based on the assumption that the natural processes operating in the past are the same as those that can be observed operating in the present

they concluded that the earth was very old and had changed its form slowly over time due to natural processes

was able to date the ages of rocks by using fossils embedded in the stone as time indicators

made use of lyells data on fossils for his theory of evolution

suggested that competition between individuals could change species

observed that in nature organisms produce more offspring than survive

was the first to talk about survival of the fittest

two geologists

english naturalist

darwins hypothesis

emerging changes on earth would then force

4 observations based on darwins theory of natural selection

2 inferences based on darwins theory of NS

change in the allele frequency in a population over time

example of a pattern

may be one method by which gene frequencies change

example of processes

had similar ideas on evolutiona and natural selection the same time as darwin

a common ancestor that lived in the past undergoes modification to live in a particular habitat accumulated over millions of years

individuals with certain characteristics survive and reproduce at a higher rate than those without those traits

if the environment changes or species move to a new location, NS results in adaptation to these new conditions and may give rise to new species

works at the level of the individual

individuals do not evolve populations do

only enhances or diminishes heritable traits

acquired traits cannot be passed on to offspring

early terrestrial vertebrates arose from a group of ____
early terrestrial vertebrates arose from ____

evolution is descent with modification

modifications should be observable as characters are altered by NS

organisms find the same way to solve the same problem given their own characterstics

3 mechanisms that cause allele frequency change

causes adaptive evolution

genetic variation makes evolution possible

variation in heritable traits is a prerequisite for evolution

genetic variation among individuals is caused by

is a product of inherited genotype and environmental influences

can only act on variation with a genetic component

genetic variation can be measured by these two

measures the average percent of loci that are heterozygous in a population

differences between gene pools of seperate populations

what causes chromosomal variation among populations? what doesnt?

geographic variation occurs in a

a graded change in a trait along a geographical axis

a change in 1 base pair in a gene can have a significant impact on phenotypes

2 ways point mutations can effect

3 changes in gene number sequence

60% of human olfaction genes have been inactivated by mutations

mutation rates

can shuffle existing alleles into new combinations

in sexual organisms, reproduction is more efficent than mutations in producing

3 processes can contribute to genetic variability

consists of all the alleles for all loci in a population

what makes a locus fixed in all individuals in a population

sequence of dna responsible for traits

allele frequencies equation

hardy weinberg theorem equation
homo
hetero

the probability of 2 independent events both occuring is the product of their individua; probabilities

HW theorem occurs only if these 5 forces arent acting against it

in the absence of the HW frequencies, they will remain the same from year to year

different populations may have different allele frequncy

3 major factors alter allele frequencies and bring about most evolutionary change

describes how allele frequencies fluctuate unpredictably from one generation to the next

tends to reduce genetic variation through the losses of alleles

look up genetic drift and flow differences

sudden reduction in population size due to a change in the environment

the resulting gene pool after the bottleneck effect may no longer be reflective of the original populations gene pool

if a population after the bottle neck effect is small

4 effects of genetic drift

movement of alleles alomg populations

how does gene flow happen

reduces variation among populations over time

new genetic variation arise by chance
beneficial alleles are sorted and favored by NS

contribution an individual makes to the gene pool of the next generation

3 modes of selection

how does selection favor certain genotypes

favors individuals at one end of the phenotypic range

favors individual at both extremes of the phenotypic range

favors intermediate variants and acts against extreme phenotypes

this occurs as the match between organisms and its environment increases

increases the frequencies of alleles that enhance survival and reproduction

natural selection for mating success

competition among individuals of one sex for mates of the opposite sex

mate choice, when individuals of one sex are choosy in selecting their mates

these are excreted by fungi to help digest the substrate into simpler compounds then be reabsorbed into the fungus

are found in fungus and digest the compounds further into usable nutrients

7 features of fungi

3 ecological roles of fungi

the vegetative bodies of most fungi are constructed of tiny filaments

interwoven mat of hyphae

hyphae that are chains of cells seperated by cross walls called

fungi that lack septa (walls seperation)

hyphae found in parasitic fungi

nutrient absorbing hyphal tips that penetrate the tissue of the host

a strong but flexible nitrogen containing polysaccharide that is composed of in fungi cell walls

spores are produced by these 2 ways

spores germinate to produce mycelia

asexual spores are ____ as a result of _____
sexual spores are the result of ______ and provide ____

sexual life cycles have these 2 processes

cytoplasmic fusion by the two parents of fungi

fusion of their compatible haploid nuclei

5 phyla of fungi

3 features of chytrids

only group with true fungi with flagella

are the most primitive fugni

form thick walled,black, over-wintering structures are called _____. This fungi is called _____

zygosporangia contain _____ and are referred to as _____ ______

bread molds are formed from what fungi

hyphae are coenocytic with septa found only in reproductive structures of this fungi

in the asexual phase of rhizopus forms _____ develops into _______ at the tips of hyphae

form mutualistic symbiotic relationships with the roots of all plants

form highly branched tree like structures inside the root cell of plants

meiosis of ascomycetes produce

asci form fruiting bodies called

ascomycetes reproduce asexually by producing enormous numbers of asexual spores called

asexual stage of ascomycetes are called

the life cycle of a mushroom usually includes a long lived _____ ______ and a short lived _______

saprobes

they obtain their nutrition from dead organic material or inorganic substrates

they obtain their nutrition from living organisms

primary role of fungi

fungi live inside plants and animals as

lichens exhibit what kind of mutalism with who

lichen with cyanobacteria are

root of vascular plants or rhizoids of nonvascular plants

how does mycorrhizae benefit in mutualism

protists are unicellular

4 features of diplomonads and parabasalids

4 features of diplomonads

example of diplomonad and its function

parabasalids example and function

euglenoids and the kinetoplastids are an example of what protist

are both photoautotrophic and heterotrophic and all have flagella

4 features of euglenozoas

protist that are characterized by an anterior pocket from which one or two flagella emerge

euglena feed by
euglenoids feed by

have a single large mitochondrion associated with a unique organelle called a kinetoplast

kinetoplast houses extracellular dna

what is trypanosoma and how is it spread

apicomplexans, ciliates, and dinoflagellate examples

flagellated protists
parasites
ciliated protist

members of alveolates belong to the clade

small membrane bound cavities under the cell surface

are parasites of animals and some cause serious human disease

tiny infectious cells in alveolate parasites

a diverse group that is named for their cilia to move and feed

cilia live as solitary cells in freshwater

cilia have 2 types of nuclei called

reason for micronuclei in cilia

2 reasons for macronucleus

in a paramecium, the cilia along the oral groove is used for

are abundant components of the phytoplankton that are suspended near the water surface

4 features of dinoflagellates

the two flagella on dino produce a spinning movement
has a characteristic chape reinforced by internal plates of cellulose

how did dinoflagellates obtain their chloroplasts? red or green algae

protist group that includes the fungus like water molds and the heterkont algae

protist that are both hetero and photosynthetic protist

2 features of stramenopiles

heterotrophic stramenopiles

oomycetes include 3

life cycle of oomycetes

2 parasites of plants and the diseases they caused (protists)

are called ray foot and have silica in their cell walls

4 features of radiolarians

3 features of entamoebas

3 features of of amoebozoans

animal like and fungus like amoeboid lineages

are considered slime molds or fungus animals

are neither fungi nor animals but represent a distinct kingdom

slime mold as sister to the fungi and animals

two distinct lineages of slime mold

brightly pigmented and heterotrophic organisms of slime molds

plasmodium phagocytes food particles

protist straddle the line between individuality and multicellularity