The fact of our own existence is almost too
surprising to bear. 
So is the fact that we are surrounded by a rich ecosystem
of animals that more or less closely resemble us,
by plants that resemble us a little less and
on which we ultimately depend for our nourishment,
and by bacteria that resemble our remoter ancestors and to which we shall all return in decay when our time is past. 
How is it that we find ourselves not merely existing
but surrounded by such complexity, such elegance,
such endless forms most beautiful and most wonderful?
The answer is this. 
It could not have been otherwise, 
given that we are capable of noticing our existence at all,
and of asking questions about it.
It is no accident, as cosmologists point out to us,that we see stars in our sky. 
There may be universes without stars in them, 
universes whose physical laws and constants leave the
primordial hydrogen evenly spread and not
concentrated into stars. 
But nobody is observing those universes,
stars are also the furnaces in which the majority of the chemical elements are forged, 
and you can't have life without a rich chemistry.
 It is no accident that we see green almost wherever we look.
It is no accident that we find ourselves perched on one tiny twig
in the midst of a blossoming and flourishing tree of life; 
no accident that we are surrounded by millions of other species,
 eating, growing, rotting, [and] swimming.
Without green plants to outnumber us at least
ten to one there would be no energy to power us. 
Without the ever-escalating arms races
between predators and prey, parasites and hosts,
without Darwin's 'war of nature', without
his 'famine and death' there would be no nervous
systems capable of seeing anything at all,
let alone of appreciating and understanding it.
And it is no accident, but the direct
consequence of evolution by non-random natural
selection - the only game in town, the greatest
show on Earth.
Theirs not to make reply,
Theirs not to reason why,
Theirs but to do and die.
