You have learnt at the beginning of this section that in sexual reproduction there is involvement of two genetically different parents. They combine their genetic material to produce a cell having a new genotype. Asexual reproduction on the other hand does not allow genetic mixing to occur. However, it should not be mistaken that asexual reproduction is a "defective" form of reproduction restricted to the primitive forms of life.
If we look into the abundance of these organisms who have persisted on earth for 3.5 million years, and their involvement in some important events of life such as food chain, clearly demonstrates that these organisms are successful and very important. These organisms must have restricted to asexual reproduction because of its simplicity to produce and also no time and energy required to find out a mate.