Question

Explain how the original remains of an insect can be preserved as a fossil in amber.

Short answer

Insects get trapped in sticky resin, which hardens into amber, preserving them as fossils.

Step-by-step solution

Understanding Amber Formation

Amber is formed from the hardened resin of ancient trees. When this resin flows out of a tree due to damage, it acts as a sticky glue capable of trapping small organisms such as insects.

Trapping of Insect in Resin

An insect gets trapped in the sticky resin. Because the resin is thick and sticky, it captures the insect entirely and protects it from predators and environmental conditions.

Resin Hardening Over Time

Over time, the resin hardens and undergoes chemical changes to become copal and eventually amber. This process can take millions of years, turning the once sticky resin into a solid, glass-like fossilized form.

Preservation of Insect

As the resin hardens into amber, the insect is preserved in a three-dimensional form. Since the resin protects the insect from decay, it can remain intact for millions of years.

Key concepts

Amber Formation

Amber is created through a fascinating natural process starting with the sap exuded from certain types of trees. When these trees experience damage, perhaps from storms or animals, they release a sticky substance known as resin. This resin oozes from the tree trunk like a thick liquid. Over an incredibly long period, usually millions of years, this resin undergoes a series of transformative changes.
The initial phase of amber formation involves the slow hardening of this resin as it is exposed to environmental elements. The resin, in its early stages, carries its soft and fluid nature and has a deep golden-yellow color. The resin's sticky quality allows it to entrap small creatures, making it crucial in the fossilization process.

• Resin begins as a thick, sticky liquid.
• Originates from tree wounds as a protective measure.
• Exposure to air, light, and heat initiates the hardening process.

Insect Preservation

Preserving insects in amber starts right from the moment they come in contact with the resin. It’s this sticky surface that plays a pivotal role in capturing and preserving the insects impeccably. When an insect lands or inadvertently encounters this resin, it quickly becomes stuck.
The resin envelops the insect, entombing it in the sticky material. This protection against external elements prevents decomposition, allowing intricate details of the insect to be preserved for ages.
Insects thus caught remain in their three-dimensional form, complete with fine features like wings and antennae. In this way, even delicate aspects of insects are protected, offering a unique glimpse into species that existed millions of years ago.

• Resin offers immediate protection upon contact.
• Preserved insects maintain remarkable structural details.
• Encasement prevents decay and microbial activity.

Resin Hardening

The hardening of resin is a gradual yet miraculous process where resin transitions from sticky to a solid state. When resin is freshly released from the tree, it is initially malleable and easily shaped.
Over time, factors such as exposure to atmospheric elements and chemical changes within the resin induce hardening. This involves polymerization - a chemical reaction that transforms resin into a tougher, more complex molecular structure.
As this happens, the resin's color deepens, and it becomes less pliable, eventually forming a hard, glass-like material. This hardened substance, once matured over prolonged periods, will become amber.

• Chemical changes lead to polymerization.
• Reaction occurs over hundreds or even thousands of years.
• Resin evolves into a durable, fossilized form.

Copal Transformation

Copal is an intermediary substance in the progression from resin to amber. It represents a stage wherein the resin has undergone some hardening but hasn't completely transformed into amber.
Copal is still a kind of resin, often younger and not as fossilized as amber. It possesses many of the same qualities as amber, like its semi-solid state and appearance, but is not fully matured.
The transformation from copal to amber can take extensive geological time. Over these eons, copal continues to undergo polymerization, losing volatile components, and hardening further to become transparent amber.

• Copal is semi-fossilized resin.
• Undergoes further chemical reactions to become amber.
• Transition signifies an ongoing process of fossilization.