Camouflage

About me: My name is Sean William Glen Steele, im in Mr. Thompsons 4th hour naturalists class. I enjoy alot of different stuff, mostly music ( i have great taste) and some sports like snowboarding, football, and paintball.

Camouflage: Mimicry and camouflage are the practices used by many animals in nature to conceal or hide themselves from predators or to blend in with their environment. It can be used many different ways, in skin color, sound, appearance, and acting. Skin color can be used as a great form of camouflage in the case of some crabs and fish. Though the two sometimes use two different types of camouflage, there is natural and cryptic coloration, they are used for the same purpose. Natural is when an animal can use parts of the environment around it on or around it's own body to blend in with the local plant life or other naturally occurring objects. Cryptic coloration is the most common form of camouflage, when an animal is born with or develops the ability to blend in with the environment because of the pigment of it's skin. Examples of these, are some crabs that allow large amounts of algae to grow on their shells to hide themselves and some fish that are born to mimic the color of the surrounding coral or plant life.

A primary defense against predators throughout the animal kingdom (and against the enemy during human warfare) is to avoid detection through camouflage. Achieving effective camouflage requires a process of actions by an animal:

1. sensing the local environment (including the animals in it)
2. filtering the sensory input
3. using selected sensory input to make a behavior decision
4. directing the appropriate effectors (be they muscles/postures/color patterns, etc.) to achieve some form of camouflage,and implementing the appropriate behavior to render the camouflage effective.

At least six mechanisms of camouflage are recognized by biologists:
general background resemblance
deceptive resemblance (including mimicry)
disruptive coloration
countershading/concealment of the shadow
rarity through polymorphism
cryptic behavior and vigilance

An interesting feature of some cephalopods is that some of the individual animals in the group can change their appearance faster than most other animals in the animal kingdom it's sometimes called “rapid, neurally controlled polymorphism.” Some squids, octopuses and cuttlefish can show 30-50 different appearances. These marine invertebrates show most aspects of their behavior through body patterning. This adaptation is really interesting because of the speed and the amount of different patterns and body colouration's these specific animals can display. The best reason for this ability is to quickly use other defense mechanisms and hide from predators.

Some camouflages are not so quick to occur however, some take generations to perfect and get right. A prime example of this generational camouflage is the case of the peppered moth. The peppered moth has been an example for industrial melanism for ages, it has been such a good example because of it's changing from a lighter shaded moth to a darker shade to blend in with the soot on the walls of it's environment. The idea behind this is that around the time of the industrial revolution soot would settle on walls making them a darker color, the light moths would not blend in with the new surroundings so it generally started to become darker to blend in.

Some of the best organisms at camouflage are insects and bugs. Many different types of insect, spiders, and other bugs are born with the natural skin tones to blend in with their natural surroundings, such as the walking stick, and praying mantis, both live in heavily wooded areas so, they are born with skin colors and pattern that make them nearly indistinguishable in their natural surroundings. Other examples of this camouflage can be found in different beetles, spiders, and flying insects. Butterflies can be an amazing example of using their natural body coloration's to blend in, and even sometimes scare away predators.

It is a safe bet that many many species of animals and other organisms would not still be around today, or would be severely endangered if it were not for camouflage. OK these don't have to count towards my words unless you want to be my favorite teacher ever and go ahead and count them, but if there is a problem with the way my article looks or is formatted, it's most likely because my computer is old and out dated to the point of spontaneous combustion.

Wikkipedia

how stuff works, animal camouflage

Camouflage in animals

animal pictures

Bookrags

Examples on Natural Slection

Natural selection is the process by which favorable traits that are heritable become more common in successive generations of a population of reproducing organisms, and unfavorable traits that are heritable become less common.

English peppered moths-
Before the industrial revolution, dark peppered moths were quite rare. In the midst of the revolution, while the air was very sooty, dark moths outnumbered light moths. Once the air became more clear, light colored moths made a comeback. Kettlewell, a scientist who studied these moths in the early 1950's, proposed the following explanation.
Before the revolution the trees where the moths lived were covered in a light lichen the light moths thrived on these trees because they were less visible to predators. The dark moths stood out and were eaten before they were able to reproduce. During the industrial era in England, the soot in the air killed the light colored lichen on the trees and the dark moths were better camouflaged

Bacteria that eat waste nylon-
The ability of a bacterium to consume nylon must be a mutation, as nylon did not even exist until the 1940’s. These bacteria metabolize short nylon oligomers with enzymes in their system. These enzymes have come from a frameshift mutation of a gene which codes for an unrelated enzyme. This has been repeated experimentally to test the validity of the theory. In the experiments, non-nylon-metabolizing strains of the bacterium Pseudomonas were grown in media with only nylon oligomers available for food. Within a few generations, the bacteria were producing the enzyme needed to metabolize the oligomers.

Natural Selection Requires...
For natural selection to occur, two requirements are essential:
There must be heritable variation for some trait. Examples: beak size, color pattern, thickness of skin, fleetness.
There must be differential survival and reproduction associated with the possession of that trait.
Unless both these requirements are met, adaptation by natural selection cannot occur.
Some examples:

If some plants grow taller than others and so are better able to avoid shading by others, they will produce more offspring. However, if the reason they grow tall is because of the soil in which their seeds happened to land, and not because they have the genes to grow tall, than no evolution will occur.
If some individuals are fleeter than others because of differences in their genes, but the predator is so much faster that it does not matter, then no evolution will occur (e.g. if cheetahs ate snails).
In addition, natural selection can only choose among existing varieties in a population. It might be very useful for polar bears to have white noses, and then they wouldn't have to cover their noses with their paws when they stalk their prey. The panda could have a much nicer thumb than the clumsy device that it does have.
When we incorporate genetics into our story, it becomes more obvious why the generation of new variations is a chance process. Variants do not arise because they are needed. They arise by random processes governed by the laws of genetics. For today, the central point is the chance occurrence of variation, some of which is adaptive, and the weeding out by natural selection of the best adapted varieties.

Evidence of Natural Selection
Let's look at an example to help make natural selection clear.
Industrial melanism is a phenomenon that affected over 70 species of moths in England. It has been best studied in the peppered moth, Biston betularia. Prior to 1800, the typical moth of the species had a light pattern (see Figure 3). Dark colored or melanic moths were rare and were therefore collectors' items.
Figure 3. Image of Peppered Moth

During the Industrial Revolution, soot and other industrial wastes darkened tree trunks and killed off lichens. The light-colored morph of the moth became rare and the dark morph became abundant. In 1819, the first melanic morph was seen; by 1886, it was far more common -- illustrating rapid evolutionary change.

Eventually light morphs were common in only a few locales, far from industrial areas. The cause of this change was thought to be selective predation by birds, which favored camouflage coloration in the moth.

In the 1950's, the biologist Kettlewell did release-recapture experiments using both morphs. A brief summary of his results are shown below. By observing bird predation from blinds, he could confirm that conspicuousness of moth greatly influenced the chance it would be eaten.

Mimicry and Camouflage

A major concern of animals and other critters is to protect themselves from predators in order to survive and reproduce and pass their genes off to a new generation. Many animals have evolved adaptations known as antipredator devices such as camouflage and chemical toxins. Animals use camouflage to blend in with their environments in an attempt to be unrecognizable by predators. Other organisms such as the monarch butterfly contain chemical toxins that are secreted into the predator’s mouth when it attempts to eat the butterfly. The monarch butterfly also has warning coloration that gives a warning sign to predators to remind them that the butterfly is toxic and should not be eaten.

These antipredator devices are so successful that other organisms have been known to mimic them. The organism that is mimicked is known as the model and the third party that is deceived by the model and its mimic is known as the receiver. The mimics have learned to take advantage of the color patterns and markings that predators have learned by experience to avoid. The model is usually a species that has an abundant population and has successfully warded off predators with an antipredator device.

Organisms have learned to mimic their surroundings or environment in an attempt to “hide” from predators. For example, lizards have learned to mimic tree trunk color which proves to be very successful as predators will simply move past them as they believe that they are simply looking at a tree. Another example of this type of mimicry can be seen with the Katydid who will mimic a leaf in both color and shape in an attempt to be hidden.

Some prey animals have evolved certain patterns on their bodies that mimic other animals in an attempt to startle their predators. The most common example of this type of mimicry can be found in some moths and butterflies who flash eye spots on their wings to predators. These eye spots startle the predator who believes that the eyes belong to a much larger animal that may be a threat to them.

In one form of mimicry known as aggressive mimicry, an organism will mimic a signal that is either deceptive or attractive to its prey. One example of this involves the praying mantis who will mimic flowers to attract insects that they can then capture and eat. Organisms can also imitate the behaviors of other organisms. Moth caterpillars, for example, will imitate the motion and body movements of a snake in order to scare off predators that are usually a prey item for snakes.

One of the most popular types of mimicry involves the warning coloration found on inedible or toxic organisms such as the monarch butterfly. Once these toxic organisms have adapted this warning coloration which warns predators to stay away, other organisms may start to mimic this warning coloration in an attempt to stay alive. Batesian mimics are those mimics that imitate unpalatable species even though they are palatable. Therefore, one species is harmful while the other is harmless. The wasp is a great example of Batesian mimicry. The wasp is the model species in this example as it possesses a sting which enables it to escape from predators. The bright warning coloration of the wasp has been mimicked by many other insects. Even though the mimics are harmless, the predator will avoid them due to bad experiences with wasps with the same coloration. With Mullerian mimicry, many unpalatable species share a similar color pattern. Mullerian mimicry proves to be successful as the predator only has to be exposed to one of the species in order to learn to stay away from all the other species with the same warning color patterns. The black and yellow striped bodies of social wasps, solitary digger wasps, and caterpillars of the cinnabar moths warn predators that the organism is inedible. This is a great example of Mullerian mimicry as all of these unpalatable, unrelated species have a shared color pattern that keeps predators away.

Mimicry is a very successful antipredator device that species have evolved over many generations. As one can see, organisms have come to mimic many different characteristics such as color patterns and behaviors. However, selection only favors the mimics when they are less common than the model. Therefore, the fitness of mimics is “negatively frequency-dependent.”


A completely different approach for deception is camouflage, whereby animals seek to look inanimate or inedible to avoid detection by predators and prey. There are many examples of rainforest species which are cryptically colored to match their surroundings. For example, the Uroplatus geckos of Madagascar are incredible masters of disguise and are practically unnoticeable to the passer-by. An even more amazing group is the katydids, a group of grasshopper-like insects found worldwide. Katydids are nocturnal insects which use their cryptic coloration to remain unnoticed during the day when they are inactive. They remain perfectly still, often in a position that makes them blend in even better. Katydids have evolved to the point where their body coloring and shape matches leaves?including half-eaten leaves, dying leaves, and leaves with bird droppings?sticks, twigs, and tree bark. Other well-known camouflage artists include beetles, mantids, caterpillars, moths, snakes, lizards, and frogs.

Some species appear to have conspicuous coloration when they are not in the proper surroundings. For example, among the brilliant butterflies of the forest, the magnificent electric blue Morpho, has iridescent blue upper wings and a seven-inch wingspan. However, because the underwings are dark, when the Morpho flies through the flickering light of the forest or even out in broad daylight, it seems to disappear. Other forest species, especially mammals, have spots or stripes to help break up the animal's outline. In the shade created by the canopy, large mammals like leopards, jaguars, ocelots, and okapi are surprisingly difficult to see with their disruptive coloration.

Artificial Selection

Competition For Resources

Competition for resources can be defined as interaction between species, in where the fitness of one is lowered by the presence of another. There are different types of competition in the natural world. When the competition is occurring inside members of a single species is called intraspecific competition. On the other hand, when members of many species are competing for something, that's called intrespecific competition.



The picture above shows interference competition which is a result of aggression. This would only occur when their competing for food, reproduction, shelter, e.c.

The competitive exclusion principle states that species less suited to compete for resources should either adapt or die out. This competition within and between species for resources plays a critical role in natural selection.






When Charles Darwin went to the Galapagos Islands he noticed that the Finches in that island had evolved over time. On the picture you notice that the beaks of the finches all are different. The cause of this is competition for resources. The finches all evolved their beaks over time to fit their diet. So Finches with big beaks will eat fruit and stuff like that. Therefore Finches with smaller beaks, their diet will consist of seeds or small insects.

As you can see animals will evolve if competition for their resources occur. As you can see on the graph below, Species A and B are being shown of the graph. Species B eliminates the resources needed to support Species A. Therefore Species B beats Species A.



Another example of competition for resources would involve trees. Some trees grow bigger than others. In the rain forest this is a benefit for the taller trees. The tall trees expand its branches and absorb all the sunlight. The branches from these trees blocks smaller trees or plants from receiving as much sunlight.So this would be competition for resources.




Hello my name is Adelina Palomino. I was born in California and moved to Kansas when I was in fourth grade. I’m in 11th grade and attend Olathe North. I love the Student Naturalist program because I like working with animals and learning about their environment.