There are probabilities, and there are possibilities, said Banerjee. Questions of origins and questions of disease control are not the same thing once human-to-human transmission has become common, said Deborah Seligsohn, an expert in environment and public health at Villanova University. From a scientific perspective, researchers are always keen to better understand how diseases evolve. The report authors offered a ranked list of four possible ways the virus could have made the jump to humans, calling a direct leap 'possible to likely' and a scenario with an intermediate animal 'likely to very likely'. In the case of Severe Acute Respiratory Syndrome (SARS)  a disease caused by a beta coronavirus, like the current coronavirus  researchers first identified the virus in February 2003.
possibly could signal a pollution or pathogenicity but is never directly asked in human-to-human question for infectious diseases.
( z0 contrast :ARG1 ( z1 possible :ARG1 ( z2 signal :ARG1 ( z3 or :op ( z4 pollute ) :op ( z5 pathogenicity ) ) ) ) :ARG2 ( z6 ask :ARG1 z1 :ARG1-of ( z7 direct ) :polarity - :subevent-of ( z8 question :ARG1 ( z9 human :prep-to ( z10 human ) ) :ARG2 ( z11 disease :ARG0-of ( z12 infect ) ) ) :time ( z13 ever ) ) :rel ( z14 possible :ARG1 z2 ) )
(z0 / contrast-01
    :ARG1 (z1 / possible-01
              :ARG1 (z2 / signal-07
                        :ARG1 (z3 / or
                                  :op1 (z4 / pollute-01)
                                  :op2 (z5 / pathogenicity))))
    :ARG2 (z6 / ask-01
              :ARG1 z1
              :ARG1-of (z7 / direct-02)
              :polarity -
              :subevent-of (z8 / question-01
                               :ARG1 (z9 / human
                                         :prep-to (z10 / human))
                               :ARG2 (z11 / disease
                                          :ARG0-of (z12 / infect-01)))
              :time (z13 / ever))
    :rel (z14 / possible-01
              :ARG1 z2))
possibly could signal a pollution or pathogenicity but is never directly asked in human - to - human question for infectious diseases .
z1 :ARG1 z2
z14 :ARG1 z2
z3 :op1 z4
z2 :ARG1 z3
z3 :op2 z5
z0 :ARG1 z1
z6 :ARG1-of z7
z6 :polarity 0
z6 :time z13
z0 :ARG2 z6
z6 :ARG1 z1
z9 :prep-to z10
z8 :ARG1 z9
z6 :subevent-of z8
z11 :ARG0-of z12
z8 :ARG2 z11
z0 :rel z14