Modify Speed
Modifying speed or magnitude of velocity is important for some living systems because it enables them to control their movement to access resources, escape predators, and more. Modifying speed requires not only overcoming inertia, but also minimizing the energy needed to make the change. Therefore, living systems have strategies to safely shift from fast to slow or slow to fast. An example is a bird called the kingfisher, which streamlines its body and feathers to quickly move from hovering over water to diving through the air and into the water. Once in the water, the kingfisher slows down by spreading its wings to avoid diving too deep.
Modify Position
Many resources that living systems require for survival and reproduction constantly change in quantity, quality, and location. The same is true of the threats that face living systems. As a result, living systems have strategies to maintain access to shifting resources and to avoid changing threats by adjusting their location or orientation. Some living systems modify their position by moving from one location to another. For those that can’t change location, such as trees, they modify position by shifting in place. An example of an organism that does both is the chameleon. This creature can move from place to place to find food or escape predators. But it also can stay in one place and rotate its eyes to provide a 360-degree view so that it can hunt without frightening its prey.
Move in/on Solids
To obtain needed resources or escape predators, some living systems must move on solid substances, some must move within them, and others must do both. Solids vary in their form; they can be soft or porous like leaves, sand, skin, and snow, or hard like rock, ice, or tree bark. Movement can involve a whole living system, such as an ostrich running across the ground or an earthworm burrowing through the soil. It can also involve just part of a living system, such as a mosquito poking its mouthparts into skin. Solids vary in smoothness, stickiness, moisture content, density, etc, each of which presents different challenges. As a result, living systems have adaptations to meet one, and sometimes multiple, challenges. For example, some insects must be able to hold onto both rough and slippery leaf surfaces due to the diversity in their environment.
Adapt Behaviors
The environment is constantly changing, and if living systems can’t adapt to these changes, they don’t survive. Environmental changes can be cyclic such as seasons, sudden such as floods or forest fires, or gradual but long-term, such as ecosystems shifting from early to mature stages. These changes require some flexibility in behavioral responses to match the specific conditions. For example, as a fish called the lamprey swims, it constantly faces changes in currents. Skin sensors help it detect those changes and adjust its motion accordingly.
Attach Temporarily
Living systems must sometimes, temporarily, stay in one place, climb or otherwise move around, or hold things together. This entails attaching temporarily with the ability to release, which minimizes energy and material use. Some living systems repeatedly attach, detach, and reattach for an extended time, such as over their lifetimes. Despite being temporary, these attachments must withstand physical and other forces until they have achieved their purpose. Therefore, living systems have adapted attachment mechanisms optimized for the amount of time or number of times they must be used. An example is the gecko, which climbs walls by attaching its toes for less than a second. Other examples include insects that attach their eggs to a leaf until they hatch, and insects whose wings temporarily attach during flight but separate after landing.
