112 as told to Eleanor Cummins / illustrations by Tara Jacoby
TALES FROM THE FIELD
Growing up, you see
the world map a lot.
In fifth grade, they
showed us the same
map, only the seven continents
were drifting around like they
did millions of years ago. That
made me see the globe in a
new way. I learned that there
have been numerous supercon-
tinents in Earth’s history, with
great names such as Rodinia,
Nuna, and Pangaea. As I got
older and began formally
studying geology, I realized
that because the tectonic
plates that make up Earth’s
surface are still shifting today,
there would be more supercon-
tinents in the future. I wanted
to be the one to predict them.
Geologists agree that in the
next 100 million or 200 million
years, the land will once again
converge and, in the process,
eliminate an ocean. But which
ocean closes is the subject of
heated debate. As a graduate
student, I built a computer
model showing how North
America and Asia might meet
somewhere near Hawaii,crushing the Pacific Ocean.
Not everyone agrees. Many ge-
ologists think we’ll revert to a
Pangaea-like supercontinent,
where the Atlantic disappears,
and South America and Africa
touch. Others (including me)
have theorized that the Indian
Ocean might close, and, in the
process, pull up Australia
between India and Japan.
Validating any model won’t
be easy. Even though comput-
ers are an incredible boon to
our field, collecting data on the
ground remains essential. But
geologists can’t set up con-
trolled experiments the way
physicists or biologists might:
Nature already acted, and all
we can do is analyze the evi-
dence left behind. Right now,
I’m in Australia doing just that
by collecting rock samples from
different layers. By measuring
the magnetic signatures of
rocks from diverse parts of the
globe, we’re piecing together
how Earth’s magnetic field
shaped continents in the past,
and where it might move them
to in the future.To figure out how T. rexes and velociraptors
strutted around, paleontologists might
measure fossilized femurs or footprints.
But my team of behavioral ecologists
turned to their living cousins: chickens.
Animal development is a time capsule.
As a chicken grows from egg to adult, it
passes through forms that look like its evo-
lutionary ancestors, including theropods,
dinosaurs with long tails that walked on
two legs. With their similar body struc-
tures, we thought that restoring an
ancestral tail might give chickens the
swagger of their ferocious forebears. First,
I tried taping weighted metal bars to the
chicks’ butts. But the “tails” would slip off
easily, and they weren’t very realistic any-
way. So we moved on to custom cabooses:
thin rods attached with form-fitting clay
and secured with Velcro belts. They’re
shaped like mini toilet plungers.
As the chicks grew, we swapped the tails
for heavier versions every few days, keep-
ing them at about 15 percent of the bird’s
weight. Slowly, the birds developed the
right muscles, and we were delighted to see
them start crouching and stretching out
their steps. Compared with control animals
without tails or with a weight over their
centers of gravity (instead of their be-
hinds), the tailed chickens’ postures
became more forward-leaning. They really
looked like little dinosaurs!YOU DID WHAT?!i stuck plungers
to chicken buttsRODRIGO VÁSQUEZ,PROFESSOR OF
BEHAVIORAL ECOLOGY AT UNIVERSITY OF
CHILE AT SANTIAGOROSS MITCHELL,RESEARCH FELLOW AT THE SCHOOL OF EARTH AND
PLANETARY SCIENCES AT CURTIN UNIVERSITY, PERTH, AUSTRALIAMY INSPIRATIONhow to predict
the next pangaea
as told to Charlie Wood