Which aspects are you questioning? It's not my favorite piece I've seen published — I don't think it covers some areas in enough detail and leaves room for insinuation (e.g. Yarima was young when they met, but it wasn't until years had gone by that a relationship occurred. They (David's parents) have spoken as recently as ~7 months ago on a satellite phone, and Yarima has expressed interested on returning to America to visit on multiple occasions. She misses David's father and the relationship they had.)
David's relationship with his Dad is still strained from when he was young, there's no denying that (from my perspective). But as David's interest in Anthropology has grown, so has their ability to find common ground as individuals. I've seen him on the phone talking with Dad for hours, just like any other son.
Is this the right place to divulge information about a third party? I realize there is an article about him posted here and that it already contains lots of details that would normally be considered private, however I feel that somehow if you have questions about this it might be better to take it off-line. Especially parts about his father and mother's relationship in the present, it has absolutely no business being in a public forum like this. We're not exactly discussing people that have been dead for 50 years.
'jameswburke claims to be his friend. I think we can leave the question of what to reveal to his discretion. What he's said so far doesn't seem to me to be particularly sensitive, nor any more private than what was in the article.
I haven't met his younger sister, but she has children of her own and is preoccupied with life at the moment.
His younger brother is also at University studying.
It took David 25 years to take this project upon himself. As things grow, I would not be surprised to see his siblings take interest and get involved, but for the time being, traveling to the Amazon just isn't feasible for either of them.
He just left for Costa Rica on a service learning trip, but I'm happy to answer what I can.