or.tho.gen.e.sis

n.（名詞）
Biology The theory that the evolution of a species is influenced most strongly by internal factors and is not subject to the external forces of natural selection.
【生物學(xué)】 直向進(jìn)化論：關(guān)于物種的進(jìn)化是受內(nèi)部因素的強(qiáng)烈影響而非外部自然選擇的影響的理論
The theory that all cultures pass through sequential periods in the same order.
直向演化論：關(guān)于所有文化都以相同的順序經(jīng)過(guò)一系列時(shí)期演化而成的理論

【引伸】
or.thogenet.ic
or.thogenet.ically
adv.（副詞）