Thanks @Jay313! Hopefully some others will have the time and opportunity to respond. I may seem to have a one-track mind with the few threads I start, all somehow related to how Adam means humanity, but it’s what I’m working on. As a non-specialist, I’m well aware of how easily I could overstep the evidence. If @JRM or others check whether I’ve done so, that would be great – but I understand that time is precious.
I think this issue matters because it changes how those like me who read only English put together what Genesis says about Adam. In my Bible, it’s clear where Adam appears in Genesis: only in chapters 4 and 5. And in the few places Adam appears, he’s an individual man. The named Adam of chapter 4 implies that chapters 2 and 3 are also taking about him even though they don’t explicitly use his name, and by using chapter 2 to interpret the first, we can also fit him into Genesis 1. But it’s also clear from my English Bibles that Adam isn’t present in Genesis after chapter 5. Adam is just one man whose short story is told near the beginning of Genesis.
So even without being a KJV-onliest, by practice I become an English-onliest in how I understand Genesis. But once I consider the Hebrew, the clear and easily distinguished individual man named Adam blurs. In Hebrew, 'adam is a term for humanity (or any human), and its use as a name is difficult to distinguish. The Hebrew first speaks of Humanity in Genesis 1 as created, male and female, to reflect God’s image. Then Genesis 2 gives the striking image of the Humanity being formed from the ground (a obvious play on words in Hebrew). The Humanity is split into man and woman, the two blissfully unite as one flesh, but then are torn apart, not only from each other but from their Creator and home. In Genesis 4:25, for the first time, the text clearly uses Humanity as a name, speaking of Humanity siring Seth.
The next chapter blurs matters even further. The list of Humanity’s offspring (5:1) begins with Humanity being God’s name for all the people, male and female, that God created (5:2). But starting at the very next sentence, Humanity becomes the father of Seth, lives 930 years and dies (5:3-5). That’s not the end: the next chapter continues Humanity’s story. God won’t strive with Humanity forever, because he is flesh (6:3). Humanity’s wickedness is great (6:5). Yahweh is sorry to have made Humanity, so Yahweh will wipe out Humanity (6:6-7). After doing so (7:21, 23), Yahweh declares that never again will the ground be cursed because of Humanity (8:21).
Humanity’s story keeps on going. It’s all one story, not cleanly divided between what is about a literal man and what is about the species as a whole. The species is repeatedly personified as a single person well beyond the few places our English Bibles use the name Adam (e.g. 'adam’s “heart is evil from his youth,” Genesis 8:21). English Bibles enforce a division between an individual man and a generic term that isn’t present in the Hebrew.
This might be the reason early interpreters had no need for an idea like original sin to explain how Adam connects to us. There was no need to connect what in Hebrew never gets separated. Adam is Humanity, and we are all part of humanity, so obviously we can find ourselves in Humanity’s story.