It depends on your religion. But even if you stick to the evoloution theory, then yes everything just appeared from nowhere. Before the big bang there was just one huge gas mass, but before the gas mass was nothing.
And it took trillions of years till our human bodies evolved.
But all the physics behind is so complicated so that even the most smartest people cannot understand all, how then shall normal people understand?
So it is then not so wrong to stick to the bible, because it does not change much if we understand the 7 days just symbolic for the entire time that had passed till modern humans came into existence.
Recycle of souls is an interesting topic. With view to physics you body like all in the universe is made of atoms, electrons, ions and many subatomar elements. If you die then these just change the form, somehow react or become consumed by other life forms, so your physical body keeps on existing in a different form.
Because of physics it can be assumed that the energy in your body, especially in the brain makes quantum leaps. This means the energy already while we live is also outside our visible dimensions. So it cannot be excluded that when people die also some of the energy also is transferred to another dimension.
If a quantum leap happens then its likely that another leap will happen to return to the initial dimension, what in this point of view would mean somehow a return of parts from the soul.