ecology and evolution exam 1

what is the scientific theory?

comprehensive explanation of a natural phenomenon supported by lots of evidence. used to interpret facts and make testable predictions

What are the two different species concepts discussed in class?

Morphological- defines a species by structural features (ex: grizzly x polar = grolar bear) ; can apply to asexual/sexual

biological- group of populations whose members have potential to interbreed in nature and produce viable, fertile offspring (ex: dog x dog) ; can’t apply to asexual

7 reproductive isolating mechanisms and which is pre zygotic or post zygotic?

Prezygotic

habitat isolation

temporal isolation

behavioral isolation

mechanical isolation

Postzygotic

reduced hybrid viability

reduced hybrid fertility

reduced hybrid fertility

offspring are viable, but sterile (ex:donkey x horse = mule)

reduced hybrid viability

offspring are produced but don’t survive (ex: gecko x gecko #2 = hybrid won’t survive)

gametic isolation

sperm of a species can’t fertilize egg of another species

mechanical isolation

morphological features prevent successful mating (ex: snails)

behavioral isolation

behaviors are different and don’t attract mates from other species (ex: blue footed boobies)

temporal isolation

species breed at different times (ex: spotted skunks)

habitat isolation

2 species don’t encounter each other, different habitats (ex: garter snakes)

crickets use species specific chirp patterns to identify a mate of their own species is…

behavioral isolation

Two species of butterfly mate where their ranges overlap and produce fertile offspring, but the hybrids are less viable than the parental forms is…

reduced hybrid viability

Two species of a plant cannot interbreed because their flowers differ in size and shape and require pollination by different species of bee is…

mechanical isolation

Two species of firefly occupy the same prairie and have similar flash patterns, but one is active for a half-hour around sunset while the other doesn’t become active until an hour after sunset is…

temporal isolation

what is allopatric speciation?

formation of a new species due to geographic isolation of populations, no interbreeding

what two processes lead to allopatric speciation?

Vicariance- species on one island together and then island splits into 2, dividing population (canyon split by river)

Dispersal- separate and all species are on on island, then part of the species moves to other island and split in half

what is sympatric speciation?

no geographical barriers allowing ancestral and new species to exist in one space

which type of speciation is more common, allopatric or sympatric?

allopatric because geographic barriers effect the gene flow

is allopatric speciation more likely to occur on an island close to a mainland or on a more isolated island of the same size?

more isolated island because it allows for the species to evolve independently away from mainland

difference between punctuated equilibria and gradualism models of speciation?

punctuated- short periods of rapid evolution (stasis)

gradualism- small changes over long periods of time (gradual)

what is systematics? how is It used to develop phylogenetic trees?

specific characteristics of species and how they relate to other species throughout time. it creates the different branches of the tree

what are two components of every binomial name? how are they written?

genus (1st) and specific epithet (2nd)

what is the binomial name of human species?

homosapiens

correct order of taxonomic hierarchy? biggest to smallest

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

are organisms in the same phylum or in the same order more closely related?

order because it is more specific (Dear King Philip Came Over For Good Soup)

what is the difference between a shared derived character and an ancestral derived character? example?

Shared- characteristics from immediate ancestors

ancestral- characteristics shared from distant ancestors

where is a true or monophyletic clade?

ABC

different steps in scientific method?

1) make an observation

2) ask a question

3) construct a hypothesis

4) test your hypothesis

5) analyze the data you collected

6) draw a conclusion

hypothesis

a specific, testable, and measurable explanation or “educated guess” ; also needs to be falsifiable

why is it important to have a large sample size in an experiment?

it helps detect real patterns, sample size allows for weather, time of season, and predators to be part of data, less incorrect information

where is a paraphyletic group?

DEF

where is a polyphyletic group?

ABCD

what’s a homologous structure?

different species with the same bones but in different sizes and proportions

vestigal structures

remains of features that served an important function in a common ancestor (ex: tailbone in humans)

analogous characters

functionally similar features that evolved independently

what do analogous characters not provide us

ancestry details

convergent evolution

evolution of similar features in distantly related groups (ex: birds, bats, flies)

what is a clade also known as

monophyletic group

evolution

change in heritable traits over generations OR descent with modification

Aristotle

scala naturae

scala naturae

life is like a complex ladder with increasing complexity

Carlos linnaeus

founder of taxonomy, binomial nomenclature

binomial nomenclature

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

George cuvier

paleontology

James hutton and charles Lyell

uniformitarianism (earths features slowly eroded)

Lamaark

this person proposed the idea of use and disuse

inheritance of acquired characteristics

Darwin’s research: voyage of the beagle

living species resembled other species from nearby regions

artificial selection

selecting/breeding organisms for certain traits

Thomas malthus

this person said over reproduction and survival

humans limited food supplies/resources

natural selection

the process by which individuals with favorable inherited traits are more likely to survive and reproduce

adaptation

inherited traits of an organism that enhance their survival and reproduction in certain environments

wallace

similar idea to darwin

Darwins research paper name

the origin of species

microevolution

change in allele frequencies in a population overtime

macroevolution

broad patterns of evolution above the species level

speciation

process by which one species splits into two or more

gene flow

genetic information is being shared by populations (breeding) gooa

what makes a good hypothesis

specific

testable

measurable

falsifiable

vicariance

physical barrier forms, separating two populations

what does sister taxa look like

a “U”

what does a polytomy look like

a “W” or a “U” with a line down the middle

basal taxon

diverges early in group and originated near common ancestor

taxonomy

scientific discipline concerned with naming organisms

what is a phylogenetic tree used for

hypothesis about evolutionary relationships