13-8TYU - Campbell Biology

Question

Many species can reproduce either asexually or sexually. Explain what you think might be the evolutionary significance of the switch from asexual to sexual reproduction that occurs in some organisms when the environment becomes unfavorable.

Step-by-Step Solution

Answer

The organism undergoes reproduction via sexual or asexual modes. The switching of the reproduction method from asexual to sexual helps the organism in unfavorable circumstances. Genetic variation is how the organism can survive in adverse conditions.

Step 1: Description of asexual reproduction

Asexual reproduction is the reproduction without the involvement of the gametes. The primitive organism undergoes the process of this type of reproduction, including bacteria, archaea, and certain other unicellular organisms.

 

Step 2: Description of sexual reproduction

The fusion of gametes occurs in sexual reproduction. The offspring produced from this kind of reproduction possess genetic features of both the parents and some new genetic features are also inherited.

 

The inheritance of new characters takes place via chromosomal transfer in the organism.  

 

Step 3: Reason for switching from asexual to sexual reproduction

Mostly higher animals with complex body organization will depend only on sexual reproduction. The organisms that are primitive in characters undergo asexual reproduction. 

 

Certain organisms can precede both types of reproduction. These types of organisms possess the evolutionary significance that during a favorable time, they can undergo an asexual reproduction method. 

 

The organism undergoes sexual reproduction during unfavorable conditions so that the genetic variations which arise out of sexual reproduction can increase the survival rate of these organisms.

 

Hence, sexual reproduction during unfavorable conditions increases the genetic variations that can help to increase the survival span of the particular organism.