Annelids with blood vessels use metanephridia to remove soluble waste products, while those without use protonephridia. Both of these systems use a two-stage filtration process, in which fluid and waste products are first extracted and these are filtered again to re-absorb any re-usable materials while dumping toxic and spent materials as urine. The difference is that protonephridia combine both filtration stages in the same organ, while metanephridia perform only the second filtration and rely on other mechanisms for the first in annelids special filter cells in the walls of the blood vessels let fluids and other small molecules pass into the coelomic fluid, where it circulates to the metanephridia. In annelids the points at which fluid enters the protonephridia or metanephridia are on the forward side of a septum while the second-stage filter and the nephridiopore (exit opening in the body wall) are in the following segment. As a result, the hindmost segment (before the growth zone and pygidium) has no structure that extracts its wastes, as there is no following segment to filter and discharge them, while the first segment contains an extraction structure that passes wastes to the second, but does not contain the structures that re-filter and discharge urine.
What annelid system combines both filtration states in one organ?
protonephridia

Some findings in the fields of cosmology, evolutionary biology and neuroscience are interpreted by atheists (including Lawrence M. Krauss and Sam Harris) as evidence that God is an imaginary entity only, with no basis in reality. A single, omniscient God who is imagined to have created the universe and is particularly attentive to the lives of humans has been imagined, embellished and promulgated in a trans-generational manner. Richard Dawkins interprets various findings not only as a lack of evidence for the material existence of such a God but extensive evidence to the contrary.
How does Dawkins interpret evidence for or against the existence of God?
a lack of evidence for the material existence

Following al-Farabi's lead, Avicenna initiated a full-fledged inquiry into the question of being, in which he distinguished between essence (Mahiat) and existence (Wujud). He argued that the fact of existence can not be inferred from or accounted for by the essence of existing things, and that form and matter by themselves cannot interact and originate the movement of the universe or the progressive actualization of existing things. Existence must, therefore, be due to an agent-cause that necessitates, imparts, gives, or adds existence to an essence. To do so, the cause must be an existing thing and coexist with its effect.
What did Avicenna start an inquiry into?
the question of being