Survival of the Punniest
What does Darwin’s theory of evolution propose about species and their ancestors?
Species change over time, new species arise from preexisting ones, and all share a common ancestor
What type of speciation occurs due to geographic isolation?
Allopatric speciation
What is a species’ niche in an ecosystem?
Its role or function, including interactions, resource use, and behaviors
What type of interaction is predation, and give an example.
(+/-); e.g., wolves hunting deer
What type of succession begins on bare rock with no prior ecosystem?
Primary succession
Which mechanism of evolution introduces variation through changes in DNA?
Mutation
What type of evolution results in unrelated species developing similar traits?
Convergent evolution
What is the difference between a fundamental niche and a realized niche?
A fundamental niche is the potential range without limiting factors, while a realized niche is the actual range with competition and predation.
What is the difference between parasitism and parasitoidism?
Parasitism doesn’t typically kill the host, while parasitoidism always results in host death as part of the parasitoid’s life cycle
Which stage of succession involves pioneer species like lichens and mosses?
Pioneer stage
How does genetic drift affect populations?
It causes random changes in allele frequencies from one generation to the next
Homologous structures indicate which type of evolution?
Divergent evolution
What principle explains why two species cannot coexist if they compete for the same resources?
The Competitive Exclusion Principle (CEP)
What defensive strategy involves blending into the environment?
Camouflage (cryptic coloration)
What distinguishes secondary succession from primary succession?
Secondary succession occurs where an ecosystem previously existed, with soil intact.
What is the term for the movement of alleles between populations due to migration?
Gene flow
What is coevolution, and give an example.
Reciprocal evolutionary changes between interacting species, such as pollinators and flowering plants
How does resource partitioning reduce competition?
By dividing resources spatially, temporally, or behaviorally to allow coexistence.
How do prey animals benefit from safety in numbers?
It reduces the likelihood of any individual being targeted by predators
What is the climax stage in ecological succession?
A stable and mature community that remains unless disturbed.
In what situation could gene flow prevent speciation, and why?
Gene flow prevents speciation by maintaining genetic similarity between populations. Gene flow counteracts divergence if individuals migrate and interbreed between populations subjected to different selective pressures.
Explain how hybrid zones provide insights into the stages of speciation and describe one example.
Hybrid zones are areas where diverging populations meet and interbreed, offering a snapshot of speciation in progress. They reveal whether reproductive barriers are incomplete, being reinforced, or breaking down. Example: European toads, Bombina bombina and B. variegata, which have a hybrid zone in Central Europe.
How does Gause's experiments with Paramecium species demonstrate both the Competitive Exclusion Principle and resource partitioning in action?
Gause's experiments showed that when P. caudatum and P. aurelia were cultured together, P. aurelia outcompeted P. caudatum, demonstrating Competitive Exclusion. However, when provided with different resources, they partitioned resources to coexist, highlighting the potential for resource partitioning to mitigate competition.
Compare and contrast Müllerian mimicry and Batesian mimicry in terms of evolutionary benefits and potential risks. Provide examples.
Müllerian mimicry involves two harmful species mimicking each other to reinforce predator avoidance (e.g., monarch and viceroy butterflies), increasing survival for both. Batesian mimicry involves a harmless species mimicking a harmful one (e.g., scarlet kingsnake mimicking coral snake), risking exposure if predators distinguish the mimic.
Describe how primary succession on a volcanic island could influence the surrounding marine ecosystem over time.
Primary succession on a volcanic island begins with colonization by lichens and mosses, creating soil. As vegetation develops, nutrients and organic matter runoff into the marine ecosystem, enhancing productivity. This supports higher trophic levels, like fish and seabirds, and establishes a dynamic land-sea ecological interaction.