Q38.2-3CC. - Campbell Biology

Question

Self-fertilization, or selfing, seems to have obvious disadvantages as a reproductive “strategy” in nature, and it has even been called an “evolutionary dead end.” So it is surprising that about 20% of angiosperm species primarily rely on selfing. Suggest a reason why selfing might be advantageous and yet still be an evolutionary dead end.

 

Step-by-Step Solution

Answer

Pollen delivery may be uncertain in populations that are scattered and sparse, so selfing may be advantageous. In the long term, selfing or self-fertilization is an evolutionary dead end because it reduces genetic variability, limiting adaptive evolution.

Step 1: Adaptive evolution

Adaptive evolution is a term that describes evolutionary changes that are tailored to a particular environment. By addressing a specific obstacle or opportunity offered by the environment, such adaptations promote survivability or reproduction. Natural selection is responsible for adaptive evolution.

Step 2: Selfing

In flowering plants, selfing, also known as self population, is the process of pollination. The stigma and anther of the same flower fuse together to generate a new offspring. It is the most prevalent pollination strategy among plants with hardly any genetic variation.

 

Step 3: Angiosperm

Within the kingdom Plantae, Angiosperm is the most extensive and most varied group. Angiosperms account for 80% of all currently known green plants. The ovule (egg) gets fertilized and develops into a seed in an enclosed hollow ovary in angiosperms, vascular seed plants.

Since there is no genetic variety in blooming plants, self-fertilization has drawbacks. It may also result in the weakening of a variety of species due to recurrent self-pollination, lowering the quality of progeny.