Ecology Past Exam Questions

biome- wide range of temperatures, very low precipitation, CAM photosynthesis, many burrowing species, many are seasonal, roadrunner, rattlesnake

desert

biome- experiences seasonal turnover, thermocline, may have anoxic regions

temperate lake

Of 687 Atlantic Puffins hatched, 272 were found to be alive at the beginning of the age interval 6-7. What is the survivorship (l6) for this population? 2.526 it is impossible to tell from this information 0.541 415 0.395

0.395

Suppose you have 2 communities that you have to compare for similarity. Community 1 contains species a, b, c, d, e, and f and in community 2 you find species b, c, g, and g. What is the Sorensen's similarity coefficient

0.4

You have surveyed a community consisting of 6 different species: it has been found that there are 8 deer, 3 foxes, 18 mice, 9 snakes, 12 toads, and 10 rabbits Given Simpson's diversity index= D= 1-p^2, what is the diversity of this community?

0.799

What is the population density of 650 Southern flying squirrels living in a 15 hectare plot of forest? (include units)

43.3 squirrels/hectare

At equilibrium, there are 50 species of birds in a particular forest in western Oregon. A large wildlife completely destroys about 1/2 of the habitat. About how many species would you expect to find when the forest reaches equilibrium once again?

45

What is the surface area/volume ratio of a box shaped organism whose dimensions are 4cm x 5cm x 1cm?

58/20= 2.9

Two species of salamander, Ambystoma maculatum and A. opacum, are competing according to the Lotka-Volterra competitor model. If the a of A maculatum on A opacum is 0.5, then 150 A maculatum depress the population growth rate by the same amount as ________ additional individuals of A opacum. (looking for a number here)

75

Suppose you are a population biologist studying a population of short-tailed shrews (Blarina brevicauda) and you need to estimate the population size of these insectivores in a local woodlot. Using the mark recapture method you catch 32 shrews that you mark and release. Several weeks later you return and catch 50 shrews, of which 18 are marked. Your estimate of the population size of shrews in this woodlot is __________. (round to the nearest individual)

89

Which of the following is an example of a density dependent factor at work? all of these are density dependent examples an early Autumn freeze kills most of the remaining tomato plants before the fruits can be harvested As the population of lemmings increases in size, more lemmings are preyed upon by the growing weasel population. A hurricane sweeps through Virginia, causing devastating floods, which destroys vast amounts of habitat, wiping out a population of the endangered Delmarva Fox squirrel. An earthquake causes a tsunami that inundates much of the coastal MidAtlantic, killing thousands.

As the population of lemmings increases in size, more lemmings are preyed upon by the growing weasel population.

Species of tolerance graph area- even when dieting too little fat in one's diet has been shown to be detrimental to one's health

B

Species of tolerance graph area- you find very few phytoplankton in the open ocean where nutrients are very limited near the surface

B

Species of tolerance graph area- environmental conditions in DE are nearly ideal for growth of the spotted lantern fly

C

Species of tolerance graph area- most ferns grow more slowly in bright sunlight than they do in shady conditions

D

Species of tolerance graph area- water temps have become too hot for red crabs to survive intertidal pools in CA

E

In regions with low levels of disturbance, diversity is generally highest since it is such an easy place to survive.

False

Stunted growth, bone deformation and muscle spasms are indicators of nitrogen deficiency, a bigger problem for carnivores than for herbivores.

False

The yellow-winged Darter dragonfly is an example of an aposematic species. Which of the following demonstrates this characteristic of this dragonfly species? Having very brightly colored wings in order to warn a predator of the dragonfly's noxious taste Having very bright colored wings in order to fool a predator into thinking that the dragonfly contains powerful toxins. Having other species members keep an eye out for predators as the dragonfly forages. Having the bright coloration in order to attract and identify conspecifics for mating Having the ability to camouflage itself in order to avoid detection by a predator.

Having very brightly colored wings in order to warn a predator of the dragonfly's noxious taste

If rising sea level drowns shorelines and effectively makes islands further away from the mainland, what would you expect to see in the curves for the appropriate island biogeography graph? Extinction rates will be lower so the extinction curve will be steeper it is impossible to predict how this would affect the curves Extinction rates will be higher so the extinction curve will be steeper Immigration rates will be lower so the immigration curve will be shallower Immigration rates will be higher so the immigration curve will be steeper

Immigration rates will be lower so the immigration curve will be shallower

Identify the False statement according to the interactions video. In general, ectoparasites are more "dangerous" to their hosts than are endoparasites all of these statements are true Interspecific communication is often involved in maintaining species relationships some mutualistic relationships appear to have evolved over time into parasitic ones some parasites can alter the behavior of their host in order to advance their own life cycles

In general, ectoparasites are more "dangerous" to their hosts than are endoparasites

Which of the following would most likely present a barrier to a population's experiencing the benefits of the rescue effect? Genetic drift Inbreeding Isolation by distance Deterministic stochasticity Delayed density dependence

Isolation by distance

In an ecosystem where koalas only eat eucalyptus and eucalyptus is only eaten by koalas, what would you expect to occur next if the koala population is increasing and the eucalyptus population is also increasing? The koala population will decrease and the eucalyptus population will increase. Both populations will decrease. it is impossible to tell what will occur next in these populations because they are in an unstable equilibrium The koala population will increase and the eucalyptus population will decrease. Both populations will reach their carrying capacity and level off.

The koala population will increase and the eucalyptus population will decrease.

A population of a species of spiders found near streams in Colorado is much more timid and darker in color than the population of lighter, aggressive spiders of the same species found in the drier uplands nearby. These would be examples of different ecotypes of this species of spider.

True

An organism with dimensions of 4 x 6 x 3 would have less difficulty exchanging materials with the environment than one with a SA / V ratio = 1.2 / 1.

True

Migration tends to equalize allele frequencies between connected populations, although genetic drift may still cause the frequencies to differ.

True

Oxygen concentration in a temperate lake varies spatially and temporally.

True

Storms, fires and floods generally act as density independent restrictions on population growth.

True

Vegetation is usually more dense and vigorous on the windward side of a mountain than on the leeward side.

True

You should expect a temperate species of squirrel to have a wider range of thermal tolerance than a tropical species would.

True

Which of the following questions is most appropriate to investigate at the population level? What is the effect of diminished resources on an individual's lifespan? What factors influence the distribution of tropical forests? What is the relationship between resource availability and birth rate? How long does it take for carbon to be cycled from the atmosphere into living tissue? What adaptations allow this organism to survive under such extreme conditions?

What is the relationship between resource availability and birth rate?

Which of the following species would probably have the most difficulty moving their habitat in a changing world? a lowland tropical lizard a salamander living near a temperate mountaintop a butterfly with a N-S home range a weedy annual plant with small wind dispersed seeds a marine fish

a salamander living near a temperate mountaintop

Which of the following is NOT a problem in trying to define a species? ability to successfully produce fertile offspring polymorphisms convergence open-circle species asexual reproduction

ability to successfully produce fertile offspring

A dark sea surface has lower ___ than the white surface of an ice field, thus the sea will absorb considerably more energy from the sun than the ice will

albedo

With the climate changing to warmer, drier conditions African savannas spread species that consumed C4 plants became more successful plants that used more C13 displaced those that used mostly C12 adaptive radiation of large herbivores occurred all of these statements are correct

all are correct

Due to their low density, North Atlantic right whales are having difficulty finding mates. As a result, the population's growth rate has been low, despite ample resources. This is an example of the ________________.

allee effect

On a trip to Australia you notice that the eucalyptus trees are quite evenly dispersed and rarely have any other plants growing nearby. You hypothesize (correctly) that this is a result of chemical competition known as _____________.

allelopathy

Based on the warming paper, biological communities

are naturally ephemeral, adjusting to changes as they arise

Spotted lanternflies are an introduced species in the US, are relatively free from competition and predation and seem to have access to relatively unlimited resources. They probably have a large niche overlap with the sympatric annual cicadas are occupying an organized niche none of these answers is correct are occupying a limited realized niche are occupying nearly their fundamental niche

are occupying nearly their fundamental niche

Yellow, blue, and orange side blotched lizards all of these statements are correct are three different species live in the tropics are polymorphic are protandrous

are polymorphic

A relatively new analytic method called song playback consists of scientists recording the songs of one population of birds and then playing them in the presence of another population. If the birds show little interest in each other's songs, they are assumed to represent different species. This is an example of ___________ isolation. behavioral outbreeding hybrid temporal geographic

behavioral

Researchers are taking substrate samples to determine what is living in the soil. They take 5 samples in one forest and then another 5 in the neighboring field, and 5 more in the marsh over the hill. These samples will be best able to determine the __ diversity of the soil

beta

Suppose you did a quadrat analysis of a population of groundwort (a plant) and found the following numbers of plants in the samples: 7, 8, 93, 12, 78, 14, 8, 87, 5, and 82. What dispersion pattern is shown by this population?

clumped

dispersion- African wild dogs practice alloparenting and help to raise each other's pups.

clustered

dispersion- in the summer you can often find salamanders by walking through the forest and looking under logs which retain moisture

clustered

interaction- a wren builds its nest in the branches of a shrub

commensalism

interaction- flying squirrels and red squirrels both use the same kind of nest cavity and food resources both of which are often limited in amount competition

competition

The Brown anole (Anolis sagrei) is a lizard native to Cuba. 50-60 years ago it colonized the US, where it is now commonly found in Florida along with the native green anole (Anolis carolinensis). Behavioral studies have found that in sympatry the brown anole forces the green anole higher into the trees although they both prefer lower perches. What effect has the introduction of the brown anole had on the niche of the green anole? caused it to become a generalist caused character displacement none of these answers is correct increased the niche overlap compressed it

compressed it

Identify the mismatched pair based upon the finch paper none of these is mismatched conjunctivitis :: introduced to control growing finch populations threshold prevalence :: > 20% highest finch populations :: first to be affected by the disease house finches :: introduced to the eastern US

conjunctivitis :: introduced to control growing finch populations

interaction- coral polyps provide protection and nutrients for algae and in turn receive organic molecules that the algae produce through photosynthesis

cooperation

biome- temperatures vary seasonally, moderate to high precipitation, thick rich soil with much organic litter, very seasonal groundcover, vertical stratification, squirrels, foxes

deciduous forest

In the Lotka-Volterra predator-prey model, the effect of a sudden increase in the a (capture efficiency) term would be a(n) _______ in the long-term average number of predators and _______ in the long-term average number of prey. increase; a decrease decrease; a decrease decrease; an increase decrease; no change increase; no change

decrease; a decrease

Reforestation of a region that was previously an agricultural field is likely to result in none of these answers is correct decreased latent heat loss increased albedo decreased sensible heat loss decreased precipitation

decreased sensible heat loss

During an El Nino event, the waters of the eastern Pacific Ocean are unusually ___ in productivity

decreased/low

if a predator uses the odor of stinkbugs to locate them to eat, you'd expect them to become less stinky over time

directional selection

timid desert spiders do better in hot dry areas, while aggressive individuals of the same species do better in cooler moister habitats

disruptive selection

Which of the following would NOT make up part of a frog's fundamental niche? all of these make up the fundamental niche the frog's reproductive requirements (ponds, etc) effects of the frog's competitors the frog's tolerated temperature range the composition of the frog's diet

effects of the frog's competitors

An epidemic disease in a population of an animal species is known as a(n) ___________________.

epizootic

Some species of African lungfish can practice ___ for as much as several years in response to dry conditions

estivation

Over time you should expect an efficient parasite to ______________ and its host to ___________________. evolve to become less lethal; evolve resistance evolve to become more lethal; have not changed in their level of resistance evolve to become more lethal; evolve resistance have not changed in its lethality; evolve resistance evolve to become less lethal; have not changed in their level of resistance

evolve to become less lethal; evolve resistance

Predators usually focus on species that are weaker competitors because they are easier to catch.

false

When they occur, population cycles are always caused by predator/prey interactions.

false

You and your brother spot the last piece of pizza at the same time. You trip your brother and therefore manage to get the pizza. This is best described as an example of scramble competition.

false

You find a brightly colored species unknown to you. You can be confident in your conclusion that it is distasteful or toxic.

false

It is not possible for a reproducing mammal to give birth to a LOT of very well developed offspring; This tradeoff is due to the principle of

false allocation

biome- slow decomposition, maintained by fires and large grazing herbivores, deep rich soils, wide range of temperatures, numerous deep rooted herbaceous species, low to moderate rainfall, ferrets, bison

grassland

Ocean sediment cores cannot be used to tell what terrestrial climate conditions were like indicate the gradual change of climate allowed for species to adapt and survive are full of fossils that can be used for tracing mass extinction events have darker color layers when the climate is hotter and drier indicate that the rocky desert in the African Rift Valley was once a deep marine sea teeming with life

have darker color layers when the climate is hotter and drier

ID the mismatched pair high diversity :: greater stability isozymes :: acclimation gene flow :: homogenizes populations hindgut fermentation :: foxes hybrid sterility :: postzygotic

hindgut fermentation :: foxes

Many species of predator exhibit relatively slow population growth, yet in some cases their numerical response to increased prey density can be quite rapid. What process would MOST likely contribute to this rapid numerical response? enhanced learning on the part of the juveniles a decrease in the gestation period of the predator resulting in increased fecundity temporary upward adjustment of b of the predator immigration of individuals from surrounding areas increased "carelessness" on the part of the prey

immigration of individuals from surrounding areas

Which of the following is NOT an example of genetic drift? in a pond, thick shelled mussels have an advantage over their thin-shelled counterparts and after several years of predation there are no thin shelled individuals left in the pond a hurricane kills almost half of the individuals in a population of red-cockaded woodpeckers and now efforts are being made to conserve the species the only blue-eyed person in a village died, leaving only gray and green eyed individuals cheetahs were hunted to a point where only a few of them existed but now, after significant efforts, the population is slowly recovering a small group of birds has been blown by a storm to an island where they start a new population

in a pond, thick shelled mussels have an advantage over their thin-shelled counterparts and after several years of predation there are no thin shelled individuals left in the pond

Lichens are symbiotic relationship between a fungus and an alga. If soil contains heavy metals or is acidic, the fungus cannot grow and lichens will be absent. Lichens therefore can be an ___ species for an environment with high air pollution

indicator

When heavily browsed by snowshoe hares, the shoots of aspen, poplar, birch and alder that are produced as replacements contain high concentrations of unpalatable chemicals, although they lack these chemicals in the absence of herbivory. This is an example of a(n) ____________ chemical defense.

inducible

Which of the following would most likely present a barrier to a population's experiencing the benefits of the rescue effect? the Allee effect delayed density dependence inbreeding genetic drift isolation by distance

isolation by distance

Two closely related species of mouse occupy a forest surrounded by fields. The amount of sunlight in this forest increases gradually from very little (practically dark) in the middle of the forest to mostly sunny near the edge. One species (A) is found in the darker regions of the forest and the other (B) is found around the bright edges. There is no overlap in their distributions. Why? the two species have distinctive and non-overlapping habitat requirements Species B can tolerate higher heat and outcompetes species A in the brighter edge regions Species A has bigger eyes and outcompetes species B in the darker areas it is impossible to answer this question without conducting experimental studies of the system the two species have very different diets

it is impossible to answer this question without conducting experimental studies of the system

If kangaroo rats were moved from the desert to northern tundra, where temperatures are much colder, and then allowed to evolve for many generations, which of the following adaptations might you expect for thermoregulation? a larger body size lighter skin color that reflects more sunlight development of more sweat glands longer legs, tail, nose and ears slower rate of metabolism

larger body size

Blue winged manakin males congregate in certain areas of the forest and perform elaborate dance displays in order to attract female attention and matings. Some males succeed with multiple females while other males never do. What is the best "description" of this mating system? male dominance resource defense handicap principle polyandry lek behavior

lek behavior

In regions of ___ disturbance, the best competitors dominant and exclude other species

low

A model is used by ecologists to quantify exact relationships between organisms and the environment analyze data that have been collected during an experiment describe how nature works by demonstrating cause and effect relationships make predictions about how nature works using a set of explicit assumptions observe how nature works in an experimental setting

make predictions about how nature works using a set of explicit assumptions

In the Cuban treefrog males consistently exhibit scramble competition in their mating behavior the sex ratio is strongly biased toward females larger males produce more sperm and thus are capable of fertilizing all of the eggs in an egg mass while smaller males cannot males are generally smaller than females the species is protandrous

males are generally smaller than females

Groups of individuals of the same species living in spatially isolated patches connected by occasional exchange of individuals among patches is called a(n) _________________.

metapopulation

The role that an organism plays within its community is known as its __________.

niche

According to research, Coho salmon have a reproductive strategy that varies with latitude. Northern populations have higher fecundity than southern populations; however, eggs laid by southern populations are larger and have greater juvenile survivorship than their northern counterparts. This is most likely because northern environments have fewer available resources southern populations have more predators than northern populations southern environments are more variable than northern environments northern environments are more variable than southern environments southern populations are more opportunistic than northern populations

northern environments are more variable than southern environments

The range of variables where a population or individual is least stressed and grows the best is referred to as the ___

optimum range

It has been found in many sexual species that it is maladaptive to reproduce with a very different individual because it results in offspring that are not well suited to the environment of either parent. This is described as

outbreeding depression

An ecologist designs an experiment to determine how water temperature affects the metabolic rate of pied kingfishers (birds that feed by plunging into water to catch fish); this is an example of ___ ecology study

physiological

At the ___ level of study, an ecologist might focus on the factors that affect the number of individuals of some of the species in an area

population

interaction- Green sea turtles forage almost exclusively on sea grasses and algae, generally preferring the tender young shoots

predation

interaction- a mantid mimicking a flower captures and consumes insects that come by to "pollinate" it

predation

Air masses descending toward the Earth's surface are characterized by low pressure are characterized by winds blowing toward these areas are warm air produce an arid climate all of these

produce an arid climate

dispersion- Cattail seeds blow across a marsh and germinate where they land.

random

Many species exhibit a different phenotype at different times of the year such as the question mark butterfly shown; this is known as

seasonal dimorphism

You've discovered a new species of crab and find it impossible to distinguish between males and females. Studying them over several years however, you find that around the same time every year some individuals produce prominent projections on their shells that they seem to use for mating with individuals without the structures. Based on this information, this species would be described as being _____________. simultaneous hermaphrodites permanently dimorphic seasonally dimorphic allometric parthenogenetic

seasonally dimorphic

It is expected that as the climate warms the taiga will migrate northward, replacing tundra. Which of the following is likely to be true? there will be decreased latent heat loss albedo will increase permafrost will increase because of increased shading by the vegetation rain shadows will develop sensible heat loss will decrease

sensible heat loss will decrease

In the southern hemisphere, the ___ are winds formed by the air that flows toward the equator in the tropic and are deflected by the Coriolis effect

southeast trade winds

a species of antelope has the greatest fitness when raising twins, with only one offspring it is often eaten and more than two rarely survive

stabilizing selection

Which of the following is an accurate comparison of the stratosphere and the troposphere stratospheric circulation directly influences oceanic circulation more weather happens in the stratosphere stratospheric ozone protects living organisms from damage by UV radiation the troposphere contains less water vapor All of these

stratospheric ozone protects living organisms from damage by UV radiation

The apparent pathway to speciation in desert spiders resulting in the upland timid spiders and the lowland aggressive spiders appears to be an example of heterozygote advantage stabilizing selection postzygotic isolation sympatric speciation allopatric speciation

sympatric speciation

biome- cold winters with lots of snow, dominated by conifers, very large in area, moose, wolverines

taiga

The RV Nautilus is currently investigating deep sea diversity at some sites in the eastern Pacific Ocean. Although they can take a few small samples their major method is using photo quadrats (photos of a standard size area) and analyzing them. How many photo quadrats do they need to analyze in order to estimate the alpha diversity of a site? take photo quadrats that sample the entire site take a few photo quadrats and then multiply the number of species found in that small area by the full area of the site take photo quadrats until the first one that shows no new species take photo quadrats until several photos in a row show very few new species

take photo quadrats until several photos in a row show very few new species

The Old World cuckoo is a brood parasite like the cowbird. It relies on other species to raise its young and thus does not invest time or energy into nest building, incubating or chick rearing. Which of the following best describes the behavior of this species? temporary, obligate, mutualist temporary, obligate, interspecific parasite permanent, facultative, interspecific parasite temporary, facultative, intraspecific parasite Permanent, obligate, intraspecific parasite

temporary, obligate, interspecific parasite

We just passed the 22nd of September (first day of astronomical fall); on that date.. we experienced our shortest day of the year the ITCZ was located at the geographic equator countries located near the equator will begin their summer season the ITCZ will be at its furthest south position (over 23oS latitude) the ITCZ was located halfway between the equator and 23oS latitude

the ITCZ was located at the geographic equator

Hurricane Sam is currently spinning out in the Atlantic, projected to continue strengthening. Which of the following characteristics would you expect to find as the storm strengthens? none of these answers is correct the storm begins moving faster over the surface of the Earth the central pressure increases generating more thunderstorms the central pressure decreases the strongest winds move further away from the eye

the central pressure decreases

For your senior thesis you are interested in studying a particular species of starfish that is found along coasts washed with cool/cold water. You should plan to travel to which of the following places for data? the Yucatan peninsula of Eastern Mexico the north coast of Australia the coast of Oregon the coast of South Korea Madagascar, off the East coast of Africa

the coast of Oregon

A volcano, like that on the Canary islands near Palma, is pouring lava into the sea and producing more land area, what would you expect to see happen in terms of its island biogeography and species diversity? the distance effect would become more important the equilibrium number of species would remain the same the extinction curve would shift upward the equilibrium number of species on the island would decrease the immigration curve would shift upward

the immigration curve would shift upward

Which of the following statements is FALSE? the sex ratio of a population is established at birth but changes over time Type I survivorship curves are associated with species with low fecundity in a population growing logistically, the maximum growth rate is when N = K/2 the logistic growth model assumes that population growth is density independent none of these statements is false

the logistic growth model assumes that population growth is density independent

If dN/dt is equal to zero, then the population size is at equilibrium the population is growing exponentially the population has gone extinct dN/dt cannot equal zero the population size is at half of its carrying capacity

the population size is at equilibrium

A cohort life table is developed by determining the number of individuals of known ages during a single time interval the survival of individuals of a known age across their lifetime none of these answers is correct how many individuals of each cohort are alive at a particular time the birth rates of a cohort of individuals

the survival of individuals of a known age across their lifetime

An α = 0 means that... there is no competition between species 1 and species 2 species 1 is at its zero isocline each individual in species 2 is the competitive equivalent of one species one individual species 1 will be outcompeted by species 2 and go extinct α cannot equal 0

there is no competition between species 1 and species 2

Which of the following characteristics is NOT generally associated with invasive species, according to the frog paper? they exhibit phenotypic plasticity they produce lots of young at a time all of these characteristics are associated with invasive species they are often generalists they have low genetic variability within the species, being very specialized for what they do so they can outcompete natives

they have low genetic variability within the species, being very specialized for what they do so they can outcompete natives

A population of elephant seals experienced a bottleneck and many of them are now found to have blue eyes

this is not selection

with time, training and lots of work, a woman has increased her muscles mass and is able to break the World's record in high jump

this is not selection

The fact that many biological problems seem to appear all at once after seeming to adjust to gradual changes is known as the ___ effect

threshold

Suppose that the trapping and marking described in the previous question is too stressful for shrews to tolerate and several of them died after being marked and released. Your previous estimate of the population size would then be ... too low too high it is impossible to tell unaffected

too high

(Back when we could still have parties), you sent out a party invitation on Instagram, and suddenly the party turned out to be MUCH more crowded than you intended. This is an example of an aggregative response.

true

An example of a predator's functional response to prey would be coyote becoming better at finding a small rodent.

true

Burrowing owls are considered to be auditory Batesian mimics of rattlesnakes.

true

Competition only occurs over limited resources.

true

Specialists should be expected to experience wider population fluctuations than generalists do

true

dispersion- Moray eels are quite solitary and aggressively compete over territorial space year round

uniform

Areas of ___ in the ocean are very productive since nutrients are brought to the surface where they can be used by primary producers

upwelling

Suppose while on your winter session trip to Southern Africa you came across an elephant on a very warm and sunny day. Which of the following strategies would it NOT be likely to be practicing for thermoregulation? evaporation from the surfaces of its nasal and oral tissues none of these, elephants are so massive that they have no issues with thermoregulation vasodilation of its peripheral blood vessels flapping its ears back and forth using the pilomotor response

using the pilomotor response

The flukes in the interactions video appear to cause major health problems in their definitive hosts would be considered macroendoparasites alter the behavior of the snails and thus increase their chances of getting themselves transferred into their intermediate hosts use the snails as a definitive host all of these statements are true

would be considered macroendoparasites

Studies on yuccas and yucca moths show that there is no conflict of interest between the yucca plants and the yucca moths this relationship is an example of facultative parasitism yucca plants reward moths that lay the most eggs this mutualism evolved from a commensalism yucca plants impose penalties on moths that lay too many eggs

yucca plants impose penalties on moths that lay too many eggs