Download Three Types of Environmental Adaptations

Three Types of Environmental Adaptations
Adaptations
Adaptation is the evolutionary process whereby an organism becomes better
able to live in its environment. Adaptations are body features and behavior
habits that help a living thing survive and reproduce in its natural environment.
Organisms, from microbes to plants and animals, inhabit environments that can
change to become drier, hotter, colder, more acidic, darker and sunnier -- with an
almost infinite number of variables. Organisms with genetic advantages, such as
a mutation that helps them survive the new conditions, pass down the change to
descendants, and it becomes prevalent in the population to be expressed as an
adaptation. The three basic types of adaptations, based on how the genetic
changes are expressed, are structural, physiological and behavioral adaptations.
Most organisms have combinations of all these types.
Structural Adaptation
An organism's environment can shape its appearance through structural
adaptations. A structural adaptation involves some part of an animal's body, such
as the size or shape of the teeth, the animal's body covering, or the way the
animal moves, which help the organism survive in its environment. Desert foxes
have large ears for heat radiation and Arctic foxes have small ears to retain body
heat. Seals have flippers to navigate water and raccoons have separate, flexible
digits to manipulate food. White polar bears blend into ice floes and spotted
jaguars into the speckled jungle shade. Trees may have corky bark to protect
from wildfires. Structural modifications affect organisms at different levels, from
the way a knee is hinged to the presence of large flight muscles and sharp
eyesight for predatory birds.
Physiological Adaptation
Physiological adaptations permit the organism to perform special functions (for
instance, making venom, secreting slime, phototropism); but also more general
functions such as growth and development, temperature regulation, ionic balance
and other aspects of homeostasis. Organisms are able to perform certain body
functions that help the organism survive in its environment. Based on body
chemistry and metabolism, physiological adaptations usually don't show from the
outside. They consist of things like more efficient kidneys for desert animals like
kangaroo rats, compounds that prevent blood coagulation in mosquito saliva, or
the presence of toxins in plant leaves to repel herbivores. Laboratory studies that
measure the contents of blood, urine and other body fluids, that trace metabolic
pathways, or microscopic studies of an organism's tissues are often necessary to
identify physiological adaptations. Sometimes detecting them is difficult if there
isn't a common ancestor or a closely related species with which to compare
findings.
Behavioral Adaptation
Adaptations that affect how an organism acts are called behavioral adaptations.
Behavior adaptations can be learned or instinctive. (a behavior an animal is born
with). Social behavior - some animals live by themselves, while other live in
groups. Behavior for protection - An animal's behavior sometimes helps to
protect the animal. For instance the opossum plays dead. A rabbit freezes when
it thinks it has been seen. Bears hibernate to escape cold; birds and whales
migrate to warmer winter climates. Desert animals are active at night during hot
summer weather. Lizards seek a sunny spot in the morning to warm up to
operating temperatures more quickly. A nesting killdeer will pretend to be injured
to lure a predator away from her young. Behavioral adaptations that involve
mating procedures, such as that exhibited by the Australian bowerbird, can be
amazingly complex. Often behavioral adaptations take careful field and
laboratory studies to bring them fully to light, and often involve physiological
mechanisms as well. Humans employ cultural adaptations as a subset of
behavioral adaptations, where people who live in a given environment learn ways
of raising the food they need and coping with the particular given climate.