Chapter 10: Darwin's First Question Vocabulary Flashcards

Vocabulary flashcards covering key speciation concepts, reproductive barriers, and genetic divergence mechanisms from Chapter 10 of The Tangled Bank.

Biological Species Concept (BSC)

A concept coined by Ernst Mayr in 1942 defining a species as a group of actually or potentially interbreeding populations which are reproductively isolated from other such groups.

Allopatry

A condition in which geographical barriers physically separate populations from each other, preventing interbreeding.

Sympatry

A condition in which species share the same geographic area and interbreeding is prevented by biological barriers.

Reinforcement

The process where natural selection acts to increase the amount of reproductive isolation between populations, such as through mate discrimination.

Ring Species

A connected series of populations where extreme far-reach populations diverge and, when coming into geographical contact at the peripheries, remain genetically distinct in the absence of interbreeding.

Alloploidy

The condition of a hybrid having two or more sets of chromosomes derived from two different species.

Horizontal Gene Transfer (HGT)

The process where microbes pass stretches of DNA directly to each other to be incorporated into the recipient's genome, contrasting with vertical gene inheritance.

Pan-genome

The total set of all genes found across different strains within a bacterial species.

Core-genome

The conserved set of genes present across all strains of a given bacterial species.

16S rRNA Gene Criterion

A phylogenetic threshold in microbiology where a microbe is considered a new species if its 16S rRNA gene sequence is less than 97% identical to a known species.

Astraptes fulgerator

The skipper butterfly species described in 1755 whose caterpillar color variations and plant food preferences led DNA sequencing to reveal 10 distinct genetic clusters.

Rhagoletis

A genus of flies in the Northeast U.S. that underwent sympatric speciation into distinct populations specialized on native hawthorn trees and introduced apple trees.

Tragopogon

The genus of Salsify flowers that demonstrated rapid speciation through allopolyploidy.

Greenish Warblers

A group of six subspecies in the Himalayas that demonstrate a ring species through diverged male song patterns and female mate preferences.