SCIENCE science.org 10 DECEMBER 2021 • VOL 374 ISSUE 6573 1331PHOTO: JACOB MILLER
By Mary Ellen HannibalW
hile global concern is focused on
how to avoid climate cataclysm,
more attention is needed on the
myriad other ways humanity is af-
fecting the living world. Even if we
could halt fossil fuel emissions to-
morrow, we would still need to make some
big changes. Evolutionary biologist Rob
Dunn’s timely new book, A Natural History
of the Future: What the Laws of Biology Tell
Us About the Destiny of the Human Species,
is a guide to this complex problem and of-
fers palatable solutions.
Homo sapiens are just one species
among millions, and yet we exert outsized
control over conditions on Earth. With un-
deniable ingenuity and brute power, we
have wrestled prairies into factory farms
and valleys into gleaming towers of ce-
ment and steel. We have stopped up rivers
and redirected them with dams and levees,
and we have hijacked nature’s timetables
to suit our expedience.
All of these interventions are too clever
by half. We have failed to take sufficient
notice of nature’s implacable power, both
invisible in the machinations of natural
selection and overwhelmingly present indrowned shorelines and skies blackened
with wildfire smoke. As Dunn puts it, “We
are like a driver who somehow gets down
the road, despite being too short to see out
the window, a little drunk, and very fond
of acceleration.”
Of all human-made habitats, our mono-
cropped farms are the largest. Accord-
ing to Dunn, the collective area of corn
planted on Earth is the size of France.
Wheat, barley, rice, sugarcane, cotton, and
tobacco fields make up a human-jiggered
geography. These vast areas produce food
for us—humanity eats more than half the
net primary production of photosynthe-
sis—but they also destroy habitats that
for millennia hosted birds, native plants,
mammals, butterflies, bees, and other di-
verse life-forms.
It may surprise the reader that in ad-
dition to displacing native species, agri-
cultural fields host “hundreds, perhaps
thousands, of pest and parasite species
that live nowhere else.” Dunn estimates
that more new species have evolved in our
crops than on the Galápagos Islands.
Cities likewise shape-shift not only their
skylines but the composition of species liv-
ing within them. In geological time, cities
have arisen so abruptly that Dunn likens
them to volcanic eruptions. Again, we crowd
many species out but create space for oth-
ers, including rats, pigeons, and bedbugs.
Dunn estimates that “no fewer than athousand animal species now live indoors.”
Meanwhile, cities and industrial agricul-
ture operations are connected by roads
and other means of transport that effec-
tively act as wildlife corridors for entities
including deadly viruses. “[W]e are invest-
ing in an infrastructure that ensures their
survival,” notes Dunn.
One way humanity arrived atop the
food chain was by eliminating predators.
“Our ancestors,” Dunn observes, “were of-
ten eaten.” But the calculus changed when
hominins began to hunt. We have been
killing those that would kill us—from big-
toothed predators to insect pests and mi-
croscopic pathogens—ever since. Our time
at the top is, however, ephemeral: “Even-
tually, our enemies catch up,” notes Dunn.
Natural selection works to sustain some-
thing like an arms race between Homo
sapiens and our perceived enemies. Dunn
describes an experiment undertaken by
Michael Baym and colleagues, in which
a giant petri plate was divided into a se-
ries of columns filled with increasing con-
centrations of antibiotics. Bacteria with
no genetic resistance to the antibiotics
were introduced into the outside (lowest-
concentration) column, “defenseless as
sheep.” The bacteria were knocked back by
the antibiotics, but some were able to re-
produce, and genetic variation emerged in
subsequent generations.
After a brief pause, “one and then many
lineages evolved resistance to the lowest
concentration in the antibiotic....” Again
and again, the bacteria slowed then surged,
generating mutations that could survive
the next round. If we paid more attention
to the rate of resistance, Dunn argues, we
could manage “the river of life” with surgi-
cal strikes rather than by bombing every-
thing in sight.
A Natural History of the Future is a clear
and important read with one flaw. Dunn
not only overuses the term “law,” he never
defines it. While concepts such as “corri-
dors” and “niche” do help govern the diver-
sity of life and are applicable whether the
species in question are hummingbirds or
cockroaches, they are not immutable laws.
His excellent explication of this could have
been achieved without fudging semantics. j10.1126/science.abl9604ANTHROPOCENEHumanity versus the world
A biologist confronts the evolutionary arms race at play
in human-remade landscapes
A Natural History of the
Future: What the Laws
of Biology Tell Us About
the Destiny of the
Human Species
Rob Dunn
Basic Books, 2021. 320 pp.INSIGHTSStudents weed an experimental plot in East Bethel, MN, where scientists are studying biodiversity and resilience.The reviewer is the author of Citizen Scientist: Searching
for Heroes and Hope in an Age of Extinction (The Experiment,
2016). Email: [email protected]