ADN

What would be the motive, though?

I suggested bacteria precisely for that reason, they have none. Many species have disappeared completely, many have changed. They are majestic in their simplicity...a plague wipes us and the bacteria that caused it will either evolve or it perishes with the remains of the host. HIV doesn't care that it dies with its host. We just pass it on, by no mandate of the infection. It does what it's learned to do, and it dies with the host.

Disiento contigo estimado marrano, a continuación unos párrafos que a la par de oficiar como respuesta a tu anterior comentario se valida literariamente como una violación a la lengua sajona mientras el sentido común observa atado de pies y manos sin poder hacer nada.

It's unlikely for a plague/bacteria to erase all the human beings from the planet, blame it to the dispersion or different weather conditions.

In history all plagues have had an effect of population "control" but never extermination.

We've been responsable for other species extinction, and i risk to say, something without precedents in nature history, alleged to the fact that we are the only specie capable of tool-making (with no competitors in the horizon so far), i don't know of any other species in this region of the universe being able to terminate us but oursleves.
We have today the nuclear potential to finish all human life, but although we are crazy our suicidal tendencies are not that up (let's keep it that way).

The run out of resources and polution will first generate a critical reduction of the numbers of mouth to fill and lungs for breathing.

IMHO Any of these treats would have to start before we reach the exit door (for example we start colonizing the space, some centuries ahead,i speculate) ... still we have time for more personal worries, as no matter if someone asures me human race will prevail ... me and my close ones won't.