BIO115 Exam 2

Miami University Dr. Scott Shreve class notes and homework quiz questions

what is speciation?

one species gradually becoming two

True or False: speciation is a single event

false

what are the three parts of the biological species concepts?

populations are able to interbreed, produce fertile offspring, and are reproductively isolated from other groups

what are the two types of mechanisms for speciation?

prezygotic and postzygotic

what does a PREzygotic barrier do?

prevents a zygote from being produced

what does a POSTzygotic barrier do?

prevents a zygote from surviving or becoming fertile

what are the 5 PREzygotic barriers?

habitat, temporal, behavioral, mechanical, gametic

what are the 2 POSTzygotic barriers?

(reduced hybrid) viability, (reduced hybrid) fertility

habitat isolation

geographical separation

temporal isolation

(looking for mates at different) time

behavioral isolation

courtship differences

mechanical isolation

incompatible sex genitalia

gametic isolation

not fertile

reduced hybrid viability

zygotes form but are not able to grow / survive

reduced hybrid fertility

zygotes form but are not fertile

example of reduced hybrid fertility

mule

when do the biological species concepts not apply?

asexual reproduction

allopatric speciation

physical barrier that allows species to diverge

sympatric speciation

no physical barrier, but pop split into 2 groups that still have contact

what prezygotic barrier does allopatric speciation begin with?

habitat isolation

what do additional isolating mechanisms do in allopatric speciation?

keeps new species separate even if contact is restored

genetic drift

random fluctuations in allele frequency

if the population is _____, then genetic drift MUST be occurring

finite

when is genetic drift happening?

always

what is the relationship between genetic drift and population size?

inversely proportional

is the presence of genetic drift weak or strong in humans?

weak

does genetic drift INC or DEC genetic variation WITHIN a population?

DEC

does genetic drift INC or DEC genetic variation AMONG populations?

INC

bottlenecking event

population suddenly much smaller than it was

are surviving traits RANDOM or NONRANDOM in the bottlenecking effect?

RANDOM

gene flow

migration of individuals among populations

how does gene flow impact variation WITHIN a population?

maintains

how does gene flow impact divergence AMONG populations? (INC or DEC)

DEC

how does gene flow impact fitness?

random (neg/pos/neutral)

natural selection requires what?

variation

balancing selection

exception that maintains variation (in natural selection)

natural selection does what to variation (INC or DEC)

DEC

what are the two types of balancing selections?

frequency-dependent and heterozygote advantage

frequency-dependent

fitness of traits changes based on how common it is in the population

heterozygote advantage

heterozygotes have greater fitness than either homozygote

example of frequency-dependent

predator looks for white fur, depleting the population, then population becomes majority brown fur and predator looks for that instead

sexual selection is a type of what?

natural selection

sexual dimorphism

males and females present differently

INTRA-sexual selection

traits evolve to help compete for mates (male vs male)

INTER-sexual selection

traits evolve to impress mates

what is a clue that sexual selection is occuring?

sexual dimorphism

example of INTRA-sexual selection trait

antlers

example of INTER-sexual selection trait

peacock feathers

Which of the following populations will not experience any genetic drift?:

A) Populations experiencing large amount of gene flow

B) Populations under strong selection

C) Very large populations

D) All of the above

E) None of the above

E (none of the above)

There two lakes with no connection between them.  Both lakes harbor a population of rare unicorn catfish.  Recent construction in the area has damage some of the unicorn catfish environment in the lakes.  There used be over one thousand unicorn catfish living in the lakes, now the population size in each is only 50 catfish.  What will happen to the amount of genetic variation between the two populations?

INC

You find a new species of insect with very large mandibles (jaws) in the males of the species.  You hypothesize that they evolved through intersexual selection.  What evidence would you look for to support that hypothesis?

Look for females tending to choose males who have larger mandibles

ecology

the study of where organisms live and why

population

all members of a particular species living in the same place at the same time

community

all populations collected in a particular habitat

ecosystem

community of species plus the nonliving aspects of an environment

population ecology

study of how + why population size changes over time

population dynamics

factors increasing population

what two general things INC a population?

birth rate and immigration rate

what two general things DEC a population?

death rate and emigration rate

what is the intrinsic growth rate formula?

r=(b-d)+(i-e)

what 2 things does the exponential model of population growth assume?

optimal conditions and unlimited resources

is the exponential model of population growth realistic? (Y/N)

N

what does the logistic model of population growth say?

rate of growth dec as population grows

what deos K equal in the logistic model of population growth?

carrying capacity

what model of population growth does this graph illustrate?

exponential

what model of population growth does this graph illustrate?

logistic

life history traits

traits that affect the schedule of reproduction and survival

what other concept applies to life hisotry traits?

natural selection

what are the 5 life history traits?

life span, age at first reproduction, frequency of reproduction, number of offspring per reproductive event, degree of parental care

fecundity

number of babies being produced

what are the two life history patterns?

r-selection and k-selection

R-selection has _____ survivorship and _____ fecundity

low, high

K-selection has _____ survivorship and _____ fecundity

high, low

what is the RED line in this graph?

R-selected

what is the BLUE line in this graph?

K-selected

life history pattern with RAPID POP GROWTH

R-selected

life history pattern with MANY OFFSPRING PER EVENT

R-selected

life history pattern with ONE REPRODUCTIVE EVENT

R-selected

life history pattern with RAPID POP GROWTH

R-selected

semelparous

reproducing one time

iteroparous

reproducing more than one time

life history pattern with LIMITED PARENTAL CARE

R-selection

life history pattern with HIGH EARLY MORTALITY

R-selected

life history pattern with SHORT LIFESPAN

R-selected

what two things must a population pick between to prioritize because of fitness trade-off?

surviving and reproducing

what is an example of a type I survivorship curve population?

humans

life history pattern with FEW OFFSPRING PER EVENT

K-selected

life history pattern with STABLE POPULATION

K-selected

life history pattern with MORE THAN ONE REPRODUCTION EVENT

K-selected

are K-selected populations semelparous or iteroparous? (SEM/ITER)

ITER

are R-selected populations semelparous or iteroparous? (SEM/ITER)

SEM

life history pattern with HIGH PARENTAL CARE

K-selected

life history pattern with LOW EARLY MORTALITY

K-selected

life history pattern with LONG LIFE SPAN

K-selected

what survivorship type are K-selected populations? (I/II/III)

I

what survivorship type are R-selected populations? (I/II/III)

III

what type does the BLUE line represent? (I/II/III)

I

what type does the RED line represent? (I/II/III)

II

what type does the GREEN line represent? (I/II/III)

III

type III on the survivorship curve has ___ EARLY mortality and ___ low LATE mortality

high, low