Actually, the kabbalistic tree of life and the cross of Christ both allude to the trees in the Garden of Eden and come from the same tradition (early Christians also used the tree of life diagram now associated with kabbalism), so this is not a matter of cultural inference from asterisms (which has its own interesting and partly lost history).
Number of human vertebrae
Those images are like saying there is a bear in the sky because someone draw a bear looking circuit between stars.
Actually, the kabbalistic tree of life and the cross of Christ both allude to the trees in the Garden of Eden and come from the same tradition (early Christians also used the tree of life diagram now associated with kabbalism), so this is not a matter of cultural inference from asterisms (which has its own interesting and partly lost history).