Complex sentence: It has been suggested that this difference in preference is because feminine women (those with high E3G levels), are more successful at obtaining investment, therefore, it is not necessary for these women to change their mating preferences during their cycles.
Split into simpler sentences: It has been suggested that this difference in preference is because feminine women (those with high E3G levels) are more successful at obtaining investment. It is not necessary for these women to change their mating preferences during their cycles.