Ecology Ch. 13

In order for an allopolyploid species to become fertile (capable of sexual reproduction), it must first double its chromosome number

Which of the following are considered to be characteristics of models used in ecological research? Artificial, insightful, abstraction

In Parks’ competition experiments with flour beetle, the outcome of competition was dependent upon the environmental conditions. Match the conditions to the outcomes.

Hot and wet >> T.castaneum usually dominates

Cool and dry >> T. confusum usually dominates

In between >> either species could win

Which of the following factors in Brown’s experiments with desert rats help to provide strong evidence of competition? Large spatial scale, long time scale, well replicated

In the Lotka-Volterra equations, the competition coefficient measures the effects of an individual of species 2 on species 1

Interference competition involves the direct interaction between individuals

Under self-thinning, plant populations become less dense as they grow older

The study of competition has gone through several phases. Rank the following in order from first to most recent. Theory, laboratory models, experimentation, re-evaluation

Competition is an important factor in the spread of invasive species

“Scramble competition” where individuals “race” to consume a limiting resource can be considered to be a synonym for exploitative competition

The Lotka-Volterra model assumes that resources will diminish as a result of both intra- and interspecific competition

When the Paramecium were grown separately, the change in carrying capacity in response to a change in food supply is evidence of interspecific competition. FALSE

In the results for their experiments with planthoppers, Dennon and Roderick found that insects grown in the highest density cages were characterized by which of the following? Reduced survivorship, decrease body length, increased development time

In the Lotka-Volterra model, when the zero growth isoclines for both species do not cross, which of the following outcomes could you expect? Only species 2 wins, only species 1 wins

When the two species were grown together, the extinction of one of the species is evidence of the competitive exclusion principle

In the Lotka-Volterra equations, when the value of the competition coefficient is greater than 1, then we can think of intraspecific competition being less than interspecific competition

An important condition of Gause’s experiments with Paramecium species was that resources were limiting

Along coastal locations with greater fetch, you would expect S. anglica to be found to be found at a higher elevation in the intertidal zone as compared to more sheltered locations

Competition between members of the same population is considered to be intraspecific competition

Overall, re-analysis of competition research has found that the importance of competition can vary among environments and organisms

The results of mathematical models in ecology can be used to generate hypotheses for experimental research

When grown separately, the carrying capacity for each Paramecium species decreased when the bacterial food supply was reduced

The local distribution of S. anglica is determined by inundation by tides and waves

Interference competition involves direct interaction between individuals

When the two species of Paramecium were grown together, reducing the food supply resulted in decreasing the time taken for one of the species to go to extinction

Being better at consuming a limiting resource than your competitor is considered to be exploitative competition

When a population is greater than its isocline of zero population growth, one would expect the population to decrease over time

In Gause’s competition experiments with Paramecium species, he was interested in finding out whether one species would drive the other to extinction

A scientist doing research on competition between crows and vultures would be studying interspecific competition

Character displacement is more likely to occur when two species are sympatric

The difference between the two self thinning rules is that the “-1/2 rule” uses total plant biomass while the “-3/2 rule” uses average plant biomass

How did Brown restrict the movement of rodents into and out of the study plots? Fencing

In the “-1/2 self-thinning relationship” we would expect the plant biomass would increase as plant density decreases

In Tillman’s experiments with grass, plants grown at higher densities had lower biomass per plant than those grown at lower densities

Self-thinning is the result of intraspecific competition

One of the six criteria for character displacement to occur is that the observed differences between sympatric and allopatric populations must have a genetic basis

The beak sizes of Darwin’s finches are related to differences in diet

When the two species of Galium were grown in acidic soils, both species grew slower than when they were grown in more basic soil

Experiments by other researchers have repeated the results of Brown’s competition experiments

The invasive marine snail Batillaria arrived in California as an “accidental tourist” associated with the introduction of oysters from Japan

The “priority effect” in competition occurs when the species that establishes itself in greater numbers first, wins. TRUE

Grosholz, in his competition experiments, found that isopods grown at higher density had reduced survivorship compared to those grown at lower densities

Byers was able to demonstrate the potential for resource competition because diatom (algae) cover decreased when both species were present at high densities

From the perspective of interspecific competition, we would expect that under the competitive exclusion principle, species living together will generally have different niches

In his experiments with barnacles, Connell looked at the effects of competition on Chthamalus by periodically scraping off Balanus that settled on the rocks

The expected changes in the populations of the small granivores was a result of competition with large granivores

In his experiments on competition between several species of desert rodents, Brown grouped the species based upon size and feeding habits

In the second set of experiments with the snails Cerithidea and Batillaria, Byers found that the growth rate of Batillaria was greater than that of Cerithidea at all densities

At the end of Tourney’s experiments, the amount of vegetation growing on the ground in the control plots was less than the amount in the trenched plots

The Lotka-Volterra model predicts that coexistence occurs when intraspecific competition is stronger than interspecific competition

When Tansely grew the two Galium species together, one species dominated in its native soil type

In the “-3/2 self-thinning rule” we would expect individual plant biomass to decrease as plant density increases

Brown hypothesized that small holes in the fencing would lead to increases in the populations of small granivorous rodents and no change in the populations of small insectivorous species

Grosholz proposed that the effects of competition between isopods was the result of increased cannibalism

The competitive exclusion principle states that two species with identical niches cannot coexist indefinitely

One of the six criteria for character displacement to occur is that differences between pairs of sympatric species must be greater than differences between allopatric populations of the same species

The purpose of Byers’ first experiments with the snails Cerithidea and Batillaria was to determine the effects of the snails density on their food supply

The purpose of Byers’ second experiments with the snails Cerithidea and Battillaria was to determine the effects of snails’ density on the growth rates of the two species

In self-thinning the “thinning” refers to a decrease in population density

Granivores are organisms that feed on seeds

The results of Brown’s experiments were consistent with his hypothesis because the populations of small granivores increased when Dipodomys was excluded

The spread of Btillaria from its initial colonization site has been limited due to lack of planktonic larvae

The “priority effect” in competition occurs when the species that starts with greater numbers wins

In Tourney’s experiments investigating competition, the purpose of trenching around the perimeter of plots was to eliminate potential root competition

In the “-1/2 self-thinning relationship” the “-1/2” refers to the slope of the line when plotting the log of the plant biomass against log of plant density

In re-analyzing earlier research on competition, Shoener’s and Connell’s research produced differing conclusions about the importance of competition in nature

As a C4 plant, one would expect S. anglica to photosynthesize better in warmer environments

The environmental conditions in which one of the Galium species dominates, when they are grown together, is considered that species’ realized niche

In general, Gurevitch found that larger experiments of longer durations had less variable results than those of smaller studies and shorter durations

Character displacement in a sympatric demonstrates the evolutionary outcomes of ecological interactions

As part of his research on the invasive snail Batillaria, Byers was able to demonstrate its competitive dominance to Cerithidea by using research plots that contained both species. FALSE

The environmental conditions in which Chthamalus grows, when Balanus is allowed to persist, can be considered its realized niche

The environmental conditions in which the Tribolium beetles could grow without other competitors can be considered their fundamental niches

One possible explanation for S. anglica having a lower upper limit to distribution at higher latitudes is competition with C3 grasses

The environmental conditions in which the Galium species could grow when grown separately can be considered their fundamental niches

The difference in results between Connell’s and Schoener’s re-analysis of competition experiments was that they used different studies and different criteria for analysis

G. fortis have larger beaks when they are sympatric to G. fulginosa in the Galapagos Islands. This characteristic displacement in beak size would suggest that the species has different feeding niches between these locations

In a re-analysis of competition studies, Gurevitch found that there were differences between studies based upon organisms and methods

The environmental conditions in which one of the Tribolium beetles dominates when grown together is considered that species’ realized niche