A mating system conundrum: hybridization inApocynum(Apocynaceae)

Individual mating decisions and hybridization.

The dynamics of gene flow among populations ultimately depend on behavioural interactions among individuals (Ritchie, 2007), construed in the broadest sense to encompass chemical and mechanical interactions in plants and microorganisms. The mechanisms underlying mate choice can, therefore, determine whether hybridization promotes or retards speciation. Further, the nature of the processes under...

Hybridization and mating system in a mixed stand of sessile and pedunculate oak

Prezygotic Barriers to Hybridization in Marine Broadcast Spawners: Reproductive Timing and Mating System Variation

Sympatric assemblages of congeners with incomplete reproductive barriers offer the opportunity to study the roles that ecological and non-ecological factors play in reproductive isolation. While interspecific asynchrony in gamete release and gametic incompatibility are known prezygotic barriers to hybridization, the role of mating system variation has been emphasized in plants. Reproductive iso...

Multiple post-mating barriers to hybridization in field crickets.

Mechanisms that prevent different species from interbreeding are fundamental to the maintenance of biodiversity. Barriers to interspecific matings, such as failure to recognize a potential mate, are often relatively easy to identify. Those occurring after mating, such as differences in the how successful sperm are in competition for fertilisations, are cryptic and have the potential to create s...

Pregnancy in a Breastfeeding Mouse without Mating

In this report, a rare case of pregnancy in a mouse without mating and during breastfeeding is presented. Out-bred NMRI mice were prepared for mating. Two female mice without superovulation were caged with one male. The next morning, vaginal plaque was not detected; therefore, females were kept in the cage with the same male for 4 more days. One of the females delivered 4 offspring: one female ...