As illustrated by the case study of plantain pussytoes, the relative costs and benefits of sexual and asexual reproduction and, hence the relative success of either reproductive method, are influenced by the selection pressures in the environment. The main benefits of asexual reproduction (apomixis) are similar to those of seed production. Like seed produced via selfing or other forms of inbreeding, the cost of asexual reproduction is that there is little chance for genetic recombination. Without genetic recombination, there is reduced ability to produce new genotypes that can be 'fit' to new or otherwise changing environments. Further, alle-les that impede survival may accumulate and ultimately end the ability of an individual to reproduce, asexually or sexually. The trade-off between agamospermy and clonal reproduction is that agamosperms produce seeds to allow long dispersal colonization, while cloning increases colonizing ability and persistence because it eliminates seedlings - the stage of growth when risk of mortality is highest.

0 0

Post a comment