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Forty million years ago a diverse community of insects living at the bottom of
a tree in a temperate forest chanced into a sticky pool of pine resin. Then a
mere 67 years ago a young boy named David Attenborough was given the amber
stone containing the entombed bugs. "Jewel of the Earth" explores the
remarkable time capsule of ancient life preserved in this and countless other
samples of fossilized tree resin, or amber.
Sir David Attenborough, now grown up and a celebrated naturalist and TV
personality, hosts the program. As he makes abundantly clear in the show, he is
still entranced with the amber specimen from his youth and the seemingly
magical quality of the material to serve as a crystal-clear window to an age
before humans walked the Earth. (For another view on why amber insects are so
fascinating, see Bitten By the Bug.)
Coincidentally, David's brother Richard starred in the movie that made amber
famous: Jurassic Park, in which Richard plays a billionaire entrepreneur
who extracts DNA from amber-entombed mosquitoes in order to clone living
replicas of their prey—dinosaurs. While such a scenario is probably
unlikely, amber can resurrect prehistoric life in a quite different way, as
NOVA demonstrates by probing the amber-encased clues that paint a fascinating
picture of ancient biomes.
For example, most of the world's amber comes from the Baltic region of
northern Europe, where, on the ample evidence of insects, plant fragments, and
other trapped material, a vast temperate forest flourished about 40 million
years ago. Attenborough's boyhood keepsake is a piece of Baltic amber, which he
investigates through a microscope with the help of biologist Elzbieta Sontag of
the University of Gdansk, finding a long-legged fly, a fungus gnat, an aphid,
an ant, and a mite—all denizens of the lower forest floor.
By contrast, much of the amber found in the Dominican Republic—the second
most significant source studied so far—is about 20 million years old and
hails from an ancient rain forest. George and Roberta Poinar of Oregon State
University have reconstructed this vanished ecosystem in spectacular detail,
based on such clues as a tadpole that probably resided in a water-filled
tropical bromeliad before being upended, along with a marsh beetle, into a
patch of tree resin that eventually turned into amber. (For more clues to the
primordial Dominican forest, see Stories in the Amber.)
An even more ancient Dominican sample, from 150 million years ago, contains a
honeypot ant. Since this ant is now found only in Australia, the specimen is
evidence for a conjectured super-continent that once comprised most of Earth's
landmasses. High-tech medical scanners have shed light on many other amber
inclusions, diagnosing a broken back on a gecko, for instance, which suggests
the lizard was a bird's prey before being accidentally dropped into resin.
The most controversial research on amber, however, is the effort to extract DNA
from trapped creatures, just like in Jurassic Park. So far, two teams,
including the Poinars, have announced success. However, follow-up studies
indicate the DNA found by both groups was a contaminant, not the real, ancient
stuff. Setbacks aside, scientists have only just begun to reveal the secrets to
be discovered in the warm, glowing, glassy world of amber.
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Host David Attenborough holds up the piece
of Baltic amber he was given as a child—a piece that contains, like many
hunks of such fossil-bearing resin, a microcosm of life that vanished millions
of years ago.
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