麻豆淫院

University of California Berkeley researchers report that females of two jumping spider species prefer red ornamented males of Habronattus americanus, a pattern that drives interspecific mating with a trend toward hybridized extinction for one.

Hybridization plays an important role in speciation across taxa, with gene flow that can increase, stabilize or erode divergence. Mate preference typically functions as the primary mating barrier between recently diverged species.

Research in Habronattus documents frequent heterospecific courtship, incomplete assortative mating, introgression and multiple hybrid zones. Within the americanus subgroup, variation in male coloration intersects with genomic patterns consistent with geography.

Previous work has described the "sea of red" hypothesis, proposing that preferences for red ornamented phenotypes would eventually dominate geographic regions inhabited by Habronattus species.

In the study, "Latent preference for red ornamentation drives interspecific mating in nascent jumping spider species (Habronattus americanus group, F. Salticidae)," in Proceedings of the Royal Society B, researchers tested female preferences between the two recently diverged species to examine the role of red coloration and predictions from the "sea of red" hypothesis.

Collections of Habronattus without overlapping territory include Habronattus sansoni (CC morph: mostly brown with black stripes above principal eyes) from near Cedar City, Utah and Habronattus americanus (PLC morph: red in pedipalp, leg and chelicera) from South Lake Tahoe, California.

Male courtship displays were recorded to a female model following standardized procedures, with representative vouchers archived at the Macaulay Library of Natural Sounds.

Heterospecific mate choice trials used a 2 脳 2 design. Females acclimated for five minutes, males were then introduced for up to 15 minutes of free interaction. Trials ended upon copulation or cannibalism. Body mass was measured after each trial.

Behavioral Observation Research Interactive Software (BORIS) scored visual phase duration, multimodal phase duration, and whether a male mounted a female. The visual phase began when a male oriented to the female and raised both anterior legs, ending at initiation of the multimodal phase or display cessation. The multi-modal phase began when a male moved anterior forelegs while producing a vibratory signal, ending at mount attempt, transition to the visual phase, being chased, or cessation of courtship.

Females of both species preferred americanus males, with americanus females mating 73% with americanus versus 24% with sansoni, and sansoni females mating 74% with americanus versus 31% with sansoni.

Painting sansoni males red increased mating success to 45% versus 11% for brown-painted controls. Americanus males showed similar rates across treatments, 54% red-painted versus 48% brown-painted.

Visual phases among successful males showed similar durations between species, and multimodal phases differed in duration with sansoni engaging in longer multimodal displays.

Experimental results are reflected in geographical records from iNaturalist which indicate red coloration dominates across the distribution of Habronattus americanus and Habronattus sansoni. Non-red coloration appears in just three pockets: Utah鈥揅olorado鈥搒outhern Wyoming, northern Washington into neighboring British Columbia, and northeastern California near Portola.

Authors conclude that strong latent female preferences can drive unidirectional introgression across species boundaries with potential genomic homogenization, that latent preferences may override preferences for existing traits and that color morph distributions are consistent with strong latent preferences across populations.

Findings show how one method of selection could lead to a species extinction via hybridization and the role of mating interactions in shaping biodiversity.

漏 2025 Science X Network