| > Could it be that there was sexual reproduction first and asexual reproduction came later? Unlikely. You can't mate with copies of yourself unless there are already multiple copies of yourself floating around. I like the story they present in the article. For simple organisms, it's fairly inexpensive to let defective individuals die off. As organisms get more complex, it starts to become more costly to allow defects in the genetic code to persist. Then it becomes worthwhile to perform "integrity checks" to correct errors in the data as it's being copied. If a population of organism is put into an environment conducive to a lot of data corruption, then the ones who are want to perform these checks are the ones who end up surviving. You could imagine that when higher complexity organisms are exposed to high-stress environments, it would help establish their population's ability to sexually reproduce. The ones who aren't doing it will tend to die off. Then as the complexity increases further, the genetic complexity itself can be a permanent endogenous source of high stress. The organism then loses the ability to produce asexually because it's no longer needed. Sexual reproduction promotes genetic complexity because it allows us to survive while having more complicated genes. The recombination and mixing-and-matching only helps further the process along. |
We don't know if early replicators were inside lipid membranes or not. If they were in the goop they'd be floating with their clones and siblings.