What two elements explain the staggering complexity around us?

i disagree that there is little difference between adult female development and adult male development. sociological studies comparing female and male pathways to adulthood, revelead that there are sustancial differences between them. particularly, female and male differ from timing of marriage, when they began to live with children and the likelihood of combining wife/husband and parent roles.

fir trees are found in areas with cooler climates. fir trees have needles for leaves and remain green year-round.