The second paper is entitled “Sex Did Not Originate as Adaptation to Stressful Environments: A Rebuttal to Eibrink et al” by David Gokhman et al (2018). Here, the authors provide evidence from experimental studies indicating that sexual reproduction predates stressful environments and was likely present even before eukaryotic organisms began utilizing oxygen-rich habitats for respiration. They argue against a key argument presented by Eibrink et al., namely that stressful environments may be essential for driving adaptation via processes such as genetic recombination due to their ability to reduce fitness plateaus associated with clonal populations (Eibrink et al 2018). Gokhman et al conclude that although environmental stressors can undoubtedly serve as selective agents favoring sexually reproducing lineages over their asexual counterparts, they were not necessary precursors for sex origin itself but rather played a more minor role than suggested by previous theories concerning this issue.

In summary, these two papers discuss different points-of-view on when exactly sex originated and what factors drove its original emergence throughout evolutionary history. While both papers make valid arguments based on available scientific evidence about how stress can shape species’ reproductive strategies today, there still remains significant disagreement over whether or not it was responsible for initiating sexual reproduction long ago in ancestral lineages prior to other events such as increased oxygen availability during early Earth’s history or increases in population size among prokaryotic organisms around 3 billion years ago (Grosberg 2012; Bell 1982; Maynard Smith 1976). As such further research into this topic is needed before any conclusions can be drawn regarding which model best explains how sexual reproduction originally arose amongst species living millions of years ago