Higher Organisms have resorted to sexual reproduction in spite of its complexity? Why?

Question

Sexual Reproduction is the one in which fusion of gametes and formation of zygote takes place.

Answer 1

that's what happens when you drink tequila.

Answer 2

Currently the thought is that this allows better resistance to pressure from the asexually reproducing pathogens, like bacteria. They can alter in response to shifts in their environment more rapidly than sexually reproducing organisms. They also produce two offspring per split increasing geometrically but producing two clones. They change by mutation rather than regular chromosome mixing.
Meanwhile sexual reproduction gets only one offspring per two gametes. So there had to be an advantage to this method. The immune system responds to the pathogenic onslaught with the high variability matching the pathogens rate of change. B-cells can "change their DNA by hypermutation, so that they form antibodies which are specifically tailored to the respective pathogen," Prof. Jean-Marie Buerstedde, explains.
While the immune cells respond as rapidly as bacteria, the other specializing cells to continue to function effectively. To augment the hypermutation there is the regular mixing from different gamete doners and crossover exchanges to ensure inclusion of new positive mutations more rapidly than asexual organisms. This ensures rate of progressive evolution (the accumulation of beneficial mutations) is faster in sexual populations than asexual.

Answer 3

Sexual reproduction allows for chromosomes to exchange material during crossing over and other ways of efficiently mixing up genetic material. Without sexual reproduction, changes would have to occur in each lineage to be preserved.

Answer 4

reproduction observed even in lower organisms i.e from spirilla,fungi.....etc though observed their complexity is increased.This is due to evolution and also for satisfying their required needs.