Variants may share some of the the same mutations, an expression of the virus-host relationship, which history must include non-human hosts. Nipah also implicates pigs, so we pay attention to the (Indian [italics]]) study that suggests SARS-CoV-2’s most ancient ancestor is a pig virus. The breathing space of mine bats is symbolic of trash promiscuity. One can see the revertant nature of the mutations, for example in Mu, where the virus may think it’s inside a minnow host:
Mu spike mutations:
T95I
Y144S
Y145N
R346K
E484K
N501Y
D614G
P681H
D109N
Fathead minnow spike, without mutating:
Y501
N109
S144
Mu spike mutations:
T95I
Y144S
Y145N
R346K
E484K
N501Y
D614G
P681H
D109N
Fathead minnow spike, without mutating:
Y501
N109
S144