BIOL 214 Chapter 22: Macroevolution, Speciation & Adaptive Radiation Study Guide | Quizlet

Who proposed the Unified Species Concept, and how does it define species?

Kevin de Queiroz proposed the concept, synthesizing previous definitions into a single framework based on evolutionary lineages.

What is sympatric distinctiveness?

Observable differences in phenotype and behavior among species that coexist in the same geographic area.

What are the primary limitations of the Biological Species Concept (BSC)?

It cannot be applied to asexual organisms or to extinct species in the fossil record.

What is a major criticism or limitation of the Phylogenetic Species Concept (PSC)?

Because it defines species as the smallest monophyletic group, it may lead to over-splitting species based on minor genetic differences.

How was the taxonomic distinction between Ficus salangii and Ficus stolonifera resolved?

Initial morphological distinctions were confirmed through phylogenetic analysis, demonstrating the crucial role of genetic data in classification.

How do Lactuca canadensis and Lactuca graminifolia maintain temporal isolation?

Lactuca canadensis flowers in the spring, whereas Lactuca graminifolia flowers in the summer, preventing natural hybridization.

How does mechanical isolation operate in Burmeistera flowers?

Structural differences in floral reproductive organs deposit pollen on specific sites, rendering cross-species pollen transfer ineffective.

What postzygotic isolating mechanism is observed in the Rana leopard frog complex?

Hybrid inviability, where hybrid offspring develop severe developmental abnormalities resulting in early mortality.

Why do mules exhibit hybrid sterility?

Chromosomal mismatches between horse and donkey chromosomes disrupt meiosis, preventing the formation of viable gametes.

How does flower color shift in Phlox drummondii when in sympatry with Phlox cuspidata?

Flower color shifts from light blue/pink in allopatry to deep red in sympatry to avoid interspecific pollination and hybridization with pink-flowered Phlox cuspidata.

How can founder events lead to reproductive isolation in Hawaiian Drosophila?

Colonization of new islands by small founder populations causes rapid divergence in courtship behavior via random genetic drift.

What morphological trait in Anolis lizards varies across habitats to mediate mate recognition and reproductive isolation?

Dewlap color.

What are the four sequential steps in the classical allopatric speciation model?

Continuous original population, geographic barrier formation, independent genetic divergence, and secondary contact.

Which bird species demonstrates allopatric divergence on islands despite phenotypic uniformity across the mainland?

The Little Paradise Kingfisher.

What is the fundamental difference between autopolyploidy and allopolyploidy?

Autopolyploidy involves chromosome duplication within a single species (e.g., $4n$ from $2n$), whereas allopolyploidy involves hybridization between two species followed by chromosome doubling ($2n_1 + 2n_2$).

What selective process drove sympatric divergence in palm trees on Lord Howe Island?

Disruptive selection favoring adaptations to different soil types despite ongoing gene flow.

What key morphological innovation spurred the adaptive radiation of over $450$ cichlid species in Lake Victoria in less than $200,000\text{ years}$?

A secondary set of pharyngeal jaws that allowed the evolution of highly specialized feeding strategies.

Into how many species did a single ancestral plant lineage diversify during the adaptive radiation of Hawaiian Lobeliads?

$125$ species, occupying habitats ranging from sea cliffs to rainforests.

What is character displacement?

The evolutionary divergence of morphological or behavioral traits in sympatric species to minimize interspecific competition for shared resources.

How do three-spined sticklebacks in British Columbia illustrate character displacement?

One sympatric species evolved a streamlined body adapted for open-water feeding, while the other evolved a stout body adapted for benthic foraging.

Who proposed the punctuated equilibrium model, and what does it state?

Niles Eldredge and Stephen Jay Gould proposed that evolutionary history consists of long periods of stasis interrupted by brief, rapid bursts of speciation.

What fossil group provides strong empirical evidence for punctuated equilibrium through long stasis and sudden morphological shifts?

Metrarabdotos bryozoans.

What is exaptation, and how is it exemplified in the origin of avian flight?

The evolutionary repurposing of existing structures for novel functions, such as dinosaur feathers and forelimbs originally evolved for insulation or display being repurposed for flight in Archaeopteryx.

What was the timing, primary cause, and scale of extinction of the Permian mass extinction?

Occurred approximately $\sim 252\text{ MYA}$, driven by widespread volcanism and global warming, resulting in the loss of up to $96\%$ of species.

What key chemical evidence supported the Alvarez hypothesis that an asteroid impact caused the K-T extinction $66\text{ million years ago}$?

Anomalously high concentrations of iridium in the boundary clay layer, an element rare in the Earth's crust but abundant in extraterrestrial meteorites.