Video answering a question about a refrigerator's defrost cycle. This video answers the question of how often does a refrigerator go into defrost. If you have questions about appliances that you want an answer to, leave them in the comment section below.ideo answering a question about a refrigerator's defrost cycle. This video answers the question of how often does a refrigerator go into defrost. If you have questions about appliances that you want an answer to, leave them in the comment section below.
1 Species Fusion-two species in a hybrid zone may have weak reproductive isolating barriers, and the two species may, over time, eventually share a common gene pool. 2  Species Stability/Hybrid Equilibrium-Hybrids are continually produced by the two parent populations in a hybrid zone.
Populus. Reproductive barriers between these species are incomplete, leading to the frequent formation of ex-tensive âmosaicâ hybrid zones (Lexer et al., 2005, 2010). Ongoing genomic studies of natural populations indicate that the species boundary is porous, with some loci resisting introgression and others crossing the barrier