Why are Jack and the others back in the 1970s

That was the one about Sun that worried me and I do not think the Others were given extreme longetivity and that kept them from having children, I think it was because they were able to bounce through time and at least in the men it would not have made an difference because men can produce sp*rm all the time while women have their eggs with them. I think the only situation was that as soon as the women got pregnant they had to leave the Island and come back when the babies were born, because the Island not being settled in time made it so that the babies and the mothers died.
We do not know if some of the Dharma Initiative were rejected. I think that Ben decided to get rid of them and the Others went along with his plan.

We are discussing LOST the Tv series about several people who land on this mysterious island that travels through time and is in the South Pacific.

Mnay thanks my friend!

You're welcome. It is sort of like science fiction and about magnetic fields. There being one in the Bermuda Triangle and where the Lost island is and there are two others, according to some theory. Of course I cannot understand how a lever can make an Island go though time.