Captured in a Golden Teardrop
BY AWAKE! WRITER IN THE DOMINICAN REPUBLIC
AN ANT scurries along a tree trunk, oblivious to the danger ahead. Suddenly, one leg becomes stuck, then another, until the ant is trapped in the tree’s honeylike resin. One more golden droplet trickles down, and the ant is engulfed. Escape becomes impossible. Finally, the sticky mass containing the ant falls to the ground. Rain washes the imprisoned ant into a river, where it is buried in silt. Millenniums later the ant is discovered, perfectly preserved in a golden teardrop. The resin has hardened into amber—one of man’s most precious treasures.
How much do we know about amber? Can amber and insects entombed in it tell us something about the distant past? Do they hold the key to recreating long-extinct forms of life?
Gold of the North
For thousands of years, man has been intrigued by amber’s mysterious origins and its warm, golden beauty. Besides, amber seemed to display amazing powers! About 600 B.C.E., Greek scientist Thales observed that when amber is rubbed with cloth, it acquires the ability to attract feathers or small pieces of straw. This “amazing power” is static electricity. In fact, in some languages the word for “electricity” is derived from the Greek word for amber—elektron. It was more than two thousand years later that English physician William Gilbert discovered that substances other than amber can also produce static electricity.
Sometime between 54 and 60 C.E., Roman Emperor Nero sent an army officer to search for the source of this precious substance. Traveling northward, he found it—the Baltic Coast—and returned with hundreds of pounds of amber. In Rome amber was valued for its beauty and its supposed ability to protect its bearer from harm. It was also an ingredient in medicines and ointments. Roman historian Pliny reported that amber was so popular that a carved amber figurine was valued more highly than a healthy slave!
The earliest civilizations of northern Europe used amber, sometimes called the gold of the north, to barter for iron, copper, and other goods from the south. During the Middle Ages, in Europe trade in and the manufacture of amber were strictly controlled by the Teutonic Knights, who had recently returned from the Crusades. Unauthorized collecting of amber was punishable by death.
Meanwhile, on the Caribbean island of Quisqueya, now the Dominican Republic and Haiti, the Taino Indians had also discovered amber. When Columbus first visited Quisqueya in 1492, he presented a young island chief with a strand of shiny amber beads. It has been said that Columbus was surprised when he received in return a pair of shoes decorated with amber beads!
What Is Amber?
Amber from the Dominican Republic is the hardened resin of an extinct species of broadleaved tropical tree. Certain related species, known locally as algarroba, still grow in the Caribbean area, as well as in Central and South America. However, the species closest to the ancient Dominican “amber tree” is found only in East Africa. Amber from the Baltic region in Europe comes from a coniferous tree.
How is amber formed? First, the bark of the tree is somehow opened—a limb is broken, the trunk is gashed, or the tree is attacked by wood-boring beetles. Then the viscous resin oozes to the surface to seal the wound. Insects or other small creatures unfortunate enough to be caught in the resin eventually become totally immersed in it. Unlike the tree’s sap, which is composed of water and nutrients, the resin consists of compounds of terpenes, alcohols, and esters. These chemicals seem to act as desiccants and antibiotics. They embalm any encapsulated insects and plants. Under the right environmental conditions, the resin slowly hardens into amber, preserving its contents intact for millenniums. Therefore, amber is the fossilized resin from ancient trees.
Finding the Lost Treasure
Although amber is found all over the globe, only about 20 areas contain enough amber to make mining it profitable. At present, most amber is mined in the Baltic region of Eastern Europe, in the Dominican Republic, and in some parts of Mexico.
Mining amber is a painstaking task. Many scientists believe that for the resin to turn into amber, it has to be buried underground, usually in wet clay or sandy sediment. Many mines in the Dominican Republic are located in high, rugged terrain covered with lush, subtropical forest. They may be accessible only by foot or burro via steep mountain trails.
Some mines are broad, deep pits. But others are narrow tunnels up to 600 feet [200 m] long. Because machinery and explosives can fracture amber, miners must laboriously chip away the hard sandstone and heavy clay by hand, using chisels, picks, and shovels. Often a candle serves as the miner’s only source of light.
From Crusty Rock to Polished Gem
After the amber is removed from the surrounding rock, the miner takes it into bright sunlight, washes it, and chips off its rocky crust on one end. He then moistens the exposed surface with oil to make it possible to look into the amber. He is looking for inclusions—fossilized vertebrates, insects, or other organic material that may be contained within the amber. An insect may be visible in 1 out of 100 pieces of Dominican amber. In contrast, insects appear in only 1 out of 1,000 pieces of Baltic amber. In part, this is because Baltic amber is usually opaque, whereas more than 90 percent of Dominican amber is transparent.
The amber is carefully sorted according to size, shape, color, and content. Most of the thousands of pieces of amber unearthed each week are small. But not all. One piece of Dominican amber weighs about 17.5 pounds [8 kg]! Small pieces with no inclusions are used for jewelry, while the most valuable pieces are reserved for private collectors or museums.
Amber appears most commonly in warm shades of yellow and gold. A few pieces of blue amber are mined each month in the Dominican Republic. Green amber is an even rarer find. It is thought that this variety of colors is due to variations in the chemical composition of the resin and of the minerals in the surrounding soil.
Visions of an Ancient Forest
Because of its unique characteristics, amber and its “prisoners” have outlasted the lush tropical ecosystem from which they came. The organic material in most fossils has become petrified—its original structure being replaced by minerals. On the other hand, amber is itself organic, as are any animals or plants it may contain. If it is transparent, its ancient treasures can be studied and photographed in three dimensions without damaging them. Thus, amber has been called a golden window to the past because it contains a record not only of the insects and small vertebrates but also of the plants and climate of long-vanished ecosystems.
What are the most valuable inclusions? Much depends on the perspective of the collector. Some of the most costly inclusions are those known among amber lovers as the three treasures—scorpions, lizards, and frogs. Because they are larger and stronger than many insects, most could have easily freed themselves from entrapment in the resin. Those that were trapped were usually very small or perhaps had been weakened by disease or injured by predators. How rare are such finds? Very rare! One collector estimates that only 30 to 40 scorpions, 10 to 20 lizards, and 8 or 9 frogs have ever been discovered. Those that are found are precious indeed. A piece of Dominican amber containing a small frog was discovered in 1997, and it has been valued at over $50,000.
For some scientists, other kinds of inclusions are even more fascinating. Because insects were often trapped quickly, many pieces of amber contain “snapshots” of ancient history. Indications of insect behavior, such as that of a predator and its prey, can be observed. Some specimens containing eggs, emerging larvae, spider cocoons with embryos, or newly hatched spiders allow scientists to study the stages of insect development. One piece of amber, kept in a museum in Stuttgart, Germany, contains an ancient colony of 2,000 ants.
Similarly, information about the flora of the ancient forest can be gleaned from inclusions. Flowers, mushrooms, moss, leaves, and seeds preserved in amber have made it possible to identify many ancient plants and trees. Moreover, scientists are fairly certain that fig trees were also present, even though none of their leaves or twigs have been found. Why? Because several species of wasp have been discovered in amber—wasps that are known to live only in figs. Therefore, it is reasonable to assume that fig trees also grew in the forest.
Reconstructing the Past?
Some years ago a popular motion picture was based on the premise that dinosaurs could be reproduced from the DNA of dinosaur blood found in mosquitoes encased in amber. Many scientists doubt that this is really possible. All living things have their own DNA, which contains the encoded instructions that determine their inherited characteristics. However, though scientific experiments have recovered small fragments of DNA from some insects and plants found in amber, these experiments fall far short of reproducing extinct creatures.
Not only is the recovered DNA damaged but it is also incomplete. By one estimate, the recoverable fragments are perhaps less than one millionth of the total information in the organism’s genetic code. The task of reconstructing that code completely has been compared to reconstructing a book having thousands of pages from one jumbled, incomplete sentence.*
In any case, the idea of cloning dinosaurs has inspired renewed interest in amber, and there are now amber exhibitions in museums around the globe. At the Amber World Museum in Santo Domingo, Dominican Republic, visitors can enjoy interactive displays and study amber under powerful microscopes. In a workshop at the museum, skilled artisans convert crude amber into beautiful jewelry and gems displaying fossils.
Amber has fascinated mankind for many centuries. Today, amber is treasured for its warm, mysterious beauty. It also provides us with valuable insight into the past.
For more information about genetics, see Awake! of March 22, 1995, pages 3-10.
[Pictures on page 17]
Various insects as well as frogs have been found encased in amber
[Pictures on page 18]
Small pieces of amber are transformed into polished gems
[Picture Credit Lines on page 17]
Insects in amber on pages 2, 16, and 17 and loose jewelry on page 18: Cortesía Museo Mundo de Ambar, Santo Domingo RD-Foto Gianfranco Lanzetti; page 17 frog: Cortesía Museo Mundo de Ambar, Santo Domingo RD e Nelson Fulgencio-Foto Gianfranco Lanzetti