Answer
First of all, there are actually two different creation stories in Genesis, the first at Genesis 1:1-2:4a and the second at verses 2:4bff. The second story is older in Hebrew belief and is more primitive than the creation story beginning in Genesis 1:1. Leon R. Kass (
The Beginning of Wisdom: Reading Genesis) says the second creation story departs from the first not only in content but also in tone, mood and orientation. He says we must scrupulously avoid reading into the second story any facts or notions taken from the first (and vice versa) if we mean to understand each story on its own terms. In the first creation story, man is made directly in the image of God (Genesis 1:27), but in the second story, man only becomes god-like at the end - "
now the man is become like one of us" (Genesis 3:22) and only because of a transgression. In the first, God only has to talk things into existence, but in the second, he needs clay to create Adam, and a rib (or side) to create Eve; this is consistent with the later Flood story, where God needs a natural flood to destroy mankind and can not simply decree it to happen.
The psalms and the Book of Job contain fragments of an even more primitive creation story. Here God has to fight the chaos monster, Leviathan. Chaos monsters were a common motif in ancient Near Eastern creation stories, providing in various ways an explanation as to why the world was created. God's proud claim to have defeated Leviathan (Job 41:1-10) shows what a hard-fought battle it was.
The creation myths that featured the chaos monsters are too varied and detailed to describe in detail, but the following brief examples are provided by Timothy K. Beal (
Religion and its Monsters). The sun god Re's battle against the dragon-like chaos god Apophis is a daily drama of world re-creation. In the Sanskrit hymns from the Indian Rig Veda, the creator god Indra must slay the chaos demon Vrtra in order to release its primordial chaos waters as a life source, thereby creating and establishing a livable cosmos, the order of which is integrally related to Vedic understanding of social order.
Some modern theists imagine Adam and Eve as more perfect than modern humans, but that with each generation their DNA gradually deteriorated, providing this as a so-called scientific basis for the extraordinarily long lives described in the Bible. So, it is interesting to compare this with one Greek mythical view (Stephen P. Kershaw,
The Greek Myths). First, the gods created a golden race of men, who lived idyllic lives until death came to them in the form of sleep and they lived on as beneficent spirits. The siver race that followed was far inferior. They lived as babies for 100 years, then brief, anguished and stupid lives marred by violence and arrogant pride. Because they spurned the gods, Zeus hid them away and they became spirits of the Underworld. The bronze race that followed was even more inferior and were variously made from the wood of ash trees, ash-tree nymphs or of 'ashen spears'. The fourth race began with the heroes who fought at Thebes and Troy, and are described as better than the bronze race. Afterwards came the race of iron, which is our world.