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ADVANCES

16 Scientific American, April 2020

ANWAR AMRO

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PALEONTOLOGY

Future Fossils

Humans’ and domesticated

animals’ influence will

overwhelm the fossil record

Humans have become a dominant force
on the planet, driving species extinctions,
transforming the landscape and changing
the climate. And this influence will likely
outlast Homo sapiens by millions of years:
we also look set to dominate paleontology
in the distant future, according to research
published in March in Anthropocene. The
new study finds that mammalian fossils
from the current people-centric geologic
age will consist almost entirely of humans,
livestock and pets.
“ We and our animals are just going to
totally flood the mammalian fossil record,”
says Roy Plotnick, a paleontologist at the
University of Illinois at Chicago and lead
author of the study. “The future fossil record
of today will include lots of human skeletons
all lined up in a row.”
The recent research was a natural follow-
up to a 2016 paper in which Plotnick and his
colleagues examined whether endangered
species would wind up in the fossil record.

They found that less than 9 percent of mam-

mals currently threatened with extinction

will likely make the cut. Af ter learning which

fossils would not be present, Plotnick says he

was curious to see which would.

So he and co-author Karen Koy, a pale-

ontologist at Missouri Western State Uni-

versity, exhaustively reviewed studies of

how the numbers of humans, livestock and

wild animals and their distribution have

changed over time, both globally and in the

state of Michigan. For the latter, they com-

pared cemetery and landfill locations to

sites where Pleistocene and Holocene

mammalian fossils tend to occur. They also

considered how human treatment of

remains differs from natural processes.

The researchers found that even as wild

animal numbers plummet worldwide, hu -

man development is also crowding out

marshlands and other

places most conducive to

fossil-forming processes.

Combined with the vast

numbers of humans and

domesticated animals oc -

cupying the planet—96 per-

cent of all mammals on

ear th are people or live-

stock, according to a 2018

study—these findings sug-

gest ver y low chances of wild animals being

represented in the fossil record. (Plotnick

and Koy also predict cats and dogs will likely

be preser ved, based on their geographical

spread.) And future fossils will probably look

much different from most found today. For

example, they will include sawed animal

bones from industrial-scale meat process-

ing, complete and aligned human skeletons

in cemeteries, and mass assemblages of

livestock carcasses in landfills.

These changes’ sheer scale is “stagger-

ing,” says Kate Lyons, a paleoecologist at

the University of Nebraska–Lincoln, who

was not involved in the new research. “As

I was reading the paper, I was thinking

sadly of all the ecological questions that I

am able to ask using the Pleistocene fossil

record that will be unanswerable using this

future fossil record.” — Rachel Nuwer

MEDICINE

A Cut Above

Blood-repelling bandage material

also helps with quick clotting

Hemorrhage —blood escaping profusely
from a ruptured vessel—is a leading cause
of potentially preventable death. Bandages
often fail to stop the bleeding. But research-
ers say they have developed a better kind
of dressing: one that repels blood and bac-
teria, promotes quick clotting and detaches
without reopening the initial wound.
While developing blood-repelling coat-
ings for medical devices, scientists at the
National University of Singapore and the
Swiss Federal Institute of Technology in
Zurich found that one mixture of carbon
nanofibers and silicone had an unexpected
effect: it boosted blood clotting. So they
sprayed the mixture onto conventional cot-
ton gauze and applied heat to make it stick.

In laboratory tests and experiments with

rats, they observed that this new bandage

promoted the production of fibrins, proteins

that form a meshlike network at wound sites

to aid clotting. The bandage also stayed dr y,

repelling blood, which made it easy to pull

away from a wound—and an investigation

using Escherichia coli showed that bacteria in

a solution could not adhere to the material.

The researchers described their findings last

December in Nature Communications.

Study co-author Choon Hwai Yap, a

biomedical engineer in Singapore, says

more tests are needed to understand why

the nanofibers encourage fibrin formation.

But he notes that producing the material is

inexpensive and could be replicated on a

larger scale. “I think the new bandage can

make a big difference in serious wounds,

such as in a car accident or on the battle-

field,” Yap says. “In these situations, you

want to prevent bleeding ver y quickly by

repelling it back into the wound, instead of

soaking and draining blood from the body.”

Esko Kankuri, a pharmacologist at the

University of Helsinki, who was not

involved in the new study, cautions that

human trials would be needed to prove the

bandage’s real capabilities. “This study pre-

sented the very first observation of the

material’s proper ties on blood and in ver y

acute, uncomplicated wounds,” Kankuri

says. “The results are very good and prom-

ising, but laboratory conditions are very far

from actual clinical reality.” — Jillian Kramer

Meat processing will produce distinctive fossils.

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