Explain the evolution of highly successful asexual organisms (1 Viewer)

[Chrisssss]

Q:
In the module 'Blueprint of Life', you have learnt about how asexual reproduction increases the genetic variety of organisms and variety is needed for evolution to occur in changing environmental conditions.

If sexual reproduction is so valuable, how would you explain the evolution of highly successful asexual organisms, such as bacteria?


My response would include the example of drug resistant strains of bacteria, for example Staphylococcus Aureus (unsure about the spelling); describing how due to asexual reproduction, a single bacterium which has a DNA sequence mutation resulting in an enzyme produced causing resistance, can cause a whole strain of resistant bacteria because they simply replicate- so any mutations are passed on resutling in success in survival. Plus basically asexually repoducing organisms such as bacteria obtain their variation from mutations; while sexual reproduction is an important source of variation it isn't the only one.

I'm overall quite unsure if I have the facts right here so corrections/ other responses would be appreciated.

 

[Nereis]

Sexual reproduction is driven by an evolutionary arms race between hosts and parasites. Where parasitic species are unknown, such as in high altitudes, plants are asexual. There is simply no need to reshuffle the "key" to the organism's immune system, so the genes will simply pass along asexually. Species of flowers such as Townsendia, that reproduce asexually in high altitudes, reproduce sexually at lower altitudes.

 

[Skater_bum]

"how asexual reproduction increases the genetic variety of organisms and variety is needed for evolution to occur in changing environmental conditions." Thats very wrong . asexual reproduction lowers genetic variety as there all the same , ( a disease that kills one asexual organism will have the ability to kill all of the organisms that spawned from it , provided mutation hasnt happend).the fact that asexual organisms are alive is highly successful enough in biological terms as they resist environmental/biological pressures.when it comes down to bacteria there all the same , and like i said earlier they will all die from a antibiotic however mutation occurs one way or another and the mutant/s live on to again produce a mass of asexual organisms.