Complex sentence: Schroder summarizes this hypothesis outlined in Alexander and Noonan's 1979 paper: if women no longer signaled the time of ovulation, men would be unable to detect the exact period in which they were fecund.
Split into simpler sentences: Schroder summarizes this hypothesis outlined in Alexander and Noonan's 1979 paper. If human females no longer signaled the time of ovulation, males would be unable to detect the exact period in which they were fecund.