The Elements of Evolution (39-2) Floral Saltation

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The vast variety of flowering plants provides ample testimony to the frequency of plant saltation. Descent through saltation is not necessarily obvious, as a parent and saltational offspring may appear selfsame.

Descent in the evening primrose family – such as from the twolobe clarkia to the rare Merced clarkia – is shown to be a product of saltation, because the 2 annual species do not reproductively hybridize.

Floral saltation seems to be more common in annuals than in other plants, but evidence suggests saltation may have played a significant role in the early evolution of woody plants.

Major developmental events, such as the specification of organ identity, are often under the control of a limited number of developmental control genes. Changes in these loci can bring about profound yet coordinated morphological changes. ~ German evolutionary biologist Günter Theißen

Floral saltation sometimes results in homeosis: the transformation of organs. Peculiar flowers, including tulips and orchids, emerged through saltation.

The western rosinweed, a daisy endemic to northern California, is emblematic of saltation caused by rapid chromosome reorganization, which is a stress response common in plants.

The diversity and success of insects owes in part to homeosis. Insect evolution offers innumerable instances of saltation. The instant expansion of legged segments in centipedes was a saltational effect.

As Reginald Punnett observed, mimicry is another well-known example of saltation.

Predators form categories to decide on prey suitability. If the categorization is based primarily on a single prey trait, a relatively small genetic change in prey may produce a large change in appearance as perceived by predators. Such feature saltation could cause a qualitative shift in categorization from suitable to unsuitable prey, thereby initiating mimicry evolution. ~ Swedish evolutionary biologist Gabriella Gamberale-Stille et al