A commentary by Emily and Dave on the comprehensive review of male-male competition and speciation by Tinghitella et al is now out in Behavioural Ecology. Whilst male-male competition should not be ignored as a source of reproductive isolation, mate choice and the role of females will generally also be needed to close the loop and hence lead to speciation.
Our note is here: Burdfield-Steel, E.R. & Shuker, D.M. (2018) Divergence is not speciation, or why we need females: a comment on Tinghitella et al. Behavioral Ecology, ary069.
And the original review is here: