Macroevolution and Selective Agents Quiz

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Questions and Answers

What concept did Gould and Lloyd regard as too restrictive?

Species extinction rates

Aggregate organismic traits

Differential speciation

Strict sense species selection (correct)

What is the main argument in favor of the 'emergent fitness concept'?

It supports organismic level selection.

It defines macroevolution narrowly.

It allows species selection to oppose organismic selection. (correct)

It suggests selection cannot act on aggregate traits.

What term did Gould use to link macroevolution with species selection?

Differential success among species (correct)

Species differentiation

Aggregate organism selection

Emergent traits theory

How did Stanley's views on species selection change over time?

He considered it subordinate in his 1979 textbook. Signup and view all the answers

What does the term 'species sorting' refer to?

A process that doesn't involve heritable traits. Signup and view all the answers

What did Stanley (1979) notably avoid in his textbook on macroevolution?

Definition of the field of macroevolution Signup and view all the answers

What is the broad sense of 'species selection' based on in this discussion?

Emergent fitness concept Signup and view all the answers

Which author linked species selection to macroevolution specifically?

Gould Signup and view all the answers

What happens to prey species A when a predator with a hunting speed higher than its escape speed appears?

It cannot respond due to lack of relevant trait variation. Signup and view all the answers

Which predator's presence leads to potential extinction of prey species A?

A predator with a hunting speed higher than the escape speed of prey species A. Signup and view all the answers

How does prey species B respond to the introduction of predator 2?

It remains unaffected due to its escape ability. Signup and view all the answers

What is a key distinction between microevolutionary and macroevolutionary responses in this context?

Both processes operate independently despite interaction. Signup and view all the answers

What type of selection occurs due to the introduction of predator 2 among the prey species?

Selection among interspecific variation. Signup and view all the answers

What is likely to happen if extreme trait values are favored in a prey species?

It will lead to both microevolutionary and macroevolutionary responses. Signup and view all the answers

What is the primary outcome of interspecific competition in macroevolution?

Displacement or extinction of ill-adapted species Signup and view all the answers

What determines whether microevolutionary responses occur in prey species A?

The presence of relevant selective advantages in the population. Signup and view all the answers

In what scenario does macroevolutionary selection become a concern for prey species?

When microevolution fails to provide an adaptive advantage. Signup and view all the answers

How does intraspecific competition relate to evolutionary change?

It mediates between selective agents and evolutionary change Signup and view all the answers

What does the Red Queen hypothesis (RQH) provide an explanation for?

Constant extinction risk of taxa within a clade Signup and view all the answers

What effect can geographical displacement have on biodiversity?

Increase species richness at beta-diversity Signup and view all the answers

What is the role of intraspecific competition in microevolution?

It mediates the response to selective pressures Signup and view all the answers

What is suggested as an additional factor in the Red Queen explanation?

Niche conservatism Signup and view all the answers

Which argument challenges the niche crowding explanation as mentioned?

Stanley's (1979) argument Signup and view all the answers

What characterizes a species in terms of maladaptive traits?

None of its parts can develop any form of the trait. Signup and view all the answers

What is a potential negative impact of interspecific competition on population sizes?

Promotion of local extinctions Signup and view all the answers

How does macroevolution affect evolutionary novelties?

It determines their proliferation within clades. Signup and view all the answers

What type of competition occurs between individuals of the same species?

Intraspecific competition Signup and view all the answers

What does the theory of natural selection imply about intraspecific competition?

It plays a privileged role in evolutionary change Signup and view all the answers

What is the expected correlation between speciation and extinction in the Red Queen hypothesis?

Speciation causes extinction. Signup and view all the answers

Which type of competition can influence microevolution?

Both intraspecific and interspecific competition Signup and view all the answers

How can interspecific competition affect rates of speciation?

Can promote allopatric speciation through local extinctions Signup and view all the answers

At the macroevolutionary level, what role does interspecific competition play?

It promotes niche differentiation. Signup and view all the answers

What factor is suggested to remain relevant even if daughter species are very similar to parent species?

Competition between them Signup and view all the answers

What is the relationship between intraspecific competition and microevolutionary responses?

It mediates selective pressures leading to microevolution Signup and view all the answers

What must occur for interspecific competition to have a microevolutionary effect?

Variation of the trait under selection must overlap between species. Signup and view all the answers

What could break down the correlation between speciation and extinction?

Very low interspecific competition Signup and view all the answers

Which statement best describes macroevolution's role in microevolutionary change?

Macroevolution determines the fate of microevolutionary change. Signup and view all the answers

How is the distinction between microevolution and macroevolution best described in terms of competition?

Microevolution can involve both intraspecific and interspecific competition, while macroevolution only involves interspecific competition. Signup and view all the answers

What was Darwin's contribution regarding competition in evolution?

He discussed both intraspecific and interspecific competition. Signup and view all the answers

What does it mean if a species is described as having no parts capable of developing new traits?

The species may face extinction due to lack of variation. Signup and view all the answers

What is the relationship between microevolution and speciation according to the content?

Microevolution is the process that drives macroevolution through speciation. Signup and view all the answers

What role does intraspecific competition play in microevolution?

It is a mediator that connects selective agents with evolutionary responses. Signup and view all the answers

What distinguishes microevolution from macroevolution?

Microevolution focuses on individual species rather than groups. Signup and view all the answers

How does intraspecific competition contribute to microevolution?

It fosters greater genetic diversity in the gene pool. Signup and view all the answers

What is implied about interspecific competition in macroevolution?

It predicts a positive correlation with origination and extinction rates. Signup and view all the answers

What unique requirement is associated with microevolution?

It requires sexual reproduction and resultant gene pool dynamics. Signup and view all the answers

What conclusion can be drawn about macroevolution compared to microevolution?

Macroevolution occurs through repeated rounds of microevolution. Signup and view all the answers

Which statement correctly explains the concept of Stanley's rule in macroevolution?

It predicts a correlation between origination and extinction rates. Signup and view all the answers

Study Notes

Macroevolution Definition

Macroevolution encompasses three categories: evolution of supraspecific taxa, evolution on a large timescale, and evolution guided by interspecific variations.
Only the third definition consistently separates macroevolution from microevolution.
Speciation exhibits both micro and macro aspects; morphological change is micro, while interspecies variation and speciation rates are macro.

Selective Agent Effects

Selective agents can differently affect intraspecific and interspecific variations.
Three situations exist: effect on one level, effect on both levels with the same polarity but potentially different intensities, and opposite effects on different levels.
In macroevolution, selective agent effects are direct. Microevolution requires intraspecific competition to mediate the effects of the selective agents.

Competition in Evolution

Intraspefic competition is crucial in microevolution, mediating the relationship between selective agents and evolutionary responses.
This mediation isn't present in macroevolution.
Interspecies competition spurs divergence in microevolution. Extinction is a macroevolutionary threat due to competitive pressures.

Macroevolution vs Microevolution

Macroevolution, often defined as the evolution of taxa above the species level (e.g., genera, families), is distinct from microevolution, which involves changes within populations.
A macroevolutionary lens focuses on species selection and long-term evolutionary patterns on geological timescales.
A microevolutionary view focuses on genetic and phenotypic changes within populations and species, such as adaptations to environmental pressures.
The difference is not in the biological processes themselves, but how those processes manifest over time.

Species Selection and Sorting

Species selection, where species are the units of selection (not individuals), is a key macroevolutionary concept.
Species sorting, or the differential success of species due to differences in speciation and extinction rates, is a way to categorize macroevolutionary phenomena as driven by species-level traits rather than individual ones.
The differential rate of speciation and extinction (Stanley's rule) are strongly correlated. This suggests that interspecific competition plays a central role in macroevolution.

Competition Across Levels

Intraspecific competition plays a distinct and crucial role in mediating microevolutionary responses to various selective forces. Unlike species competition, it's vital to microevolution.
Interspecific (between different species) competition directly influences species survival and diversification in macroevolution.

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Description

Test your understanding of macroevolution concepts, including the distinctions between macroevolution and microevolution. Explore how selective agents influence variations within and across species and the importance of competition in evolution.