Predator- Prey Dynamics and
Evolution
Everything is food. Well, let’s say potential food. Rain
forests abound in animal life and every animal, so it
would seem, is potential sustenance for some other
animal. Part of learning how to see when inside a rain
forest, or any other habitat for that matter, is to realize
that many creatures, ranging from various vertebrates
to insects, spiders, and other invertebrates are adorned
in colors and patterns that make them difficult to
detect. Other creatures wear bold easy- to- see colors.
Some even wear both types of colors. Why is this?
Plants are not immune from predation either, which
in their case is called herbivory. Why don’t all of the
collective insect and other herbivores, such as sloths,
just eat all of the plants? After all, the plants cannot
run away. But perhaps they can fight back. It really is
“a jungle out there,” an ongoing evolutionary arms race
played out in ecological time. That’s what this chapter
is mostly about.
Cryptic Coloration: The Fine Art of
Blending In
The Neotropical boa constrictor (Boa constrictor),
if placed on a plain table, appears boldly patterned,
complexly colored in brown and gold, with stripes,
diamonds, and other markings. Once on the rain forest
floor resting on leaf litter, however, the snake seems to
effectively blend into the background (plates 11- 1– 2).
Some animals such as the blue morpho butterflies
(Morpho spp.; plates 11- 3– 4) are very obvious in flight
but not nearly so obvious when resting on a trunk or
leaf with their wings closed. In essence, morphos have
it both ways, being fairly cryptic when at rest and
obvious when in flight.
Crypsis, or cryptic coloration, pattern, behavior, or
form, is nature’s camouflage. Thousands of species
of tropical (and nontropical) insects, spiders, birds,
mammals, and reptiles exhibit cryptic patterning and
coloration to various degrees. It is a prevalent reality
of nature both on land and in the seas. A sampling of
cryptic creatures appears in plates 11- 5– 16.
Chapter 11. Evolutionary Arms Races: More Coevolution, More Complexity
Plate 11- 3.Plates 11- 3 and 11- 4. A morpho butterfly with its wings closed
(11- 3) and another with wings opened (11- 4). Photos by
Andrew Whittaker.Plate 11- 4.181