In this AP Biology review, we will answer the question: what is ecology and what do you need to know about ecology for the AP bio exam. Ecology is usually one of the first topics that students review in AP Bio, making it one of the easier things to forget. In this article, “What Is Ecology? An AP Biology Review” we will review what ecology is, the levels of an ecological system, some specific sects of ecology, and finally a question that you could see on your AP Biology exam.
What is Ecology?
Ecology is the study of interactions between organisms and the environment. The environment that organisms live in includes both abiotic and biotic factors. Abiotic factors are the nonliving components of the environment; these factors include the sun, water, temperature, nutrients, etc. Biotic factors are the factors in the environment that are living; these factors include prey, resources, and predators. Ecologists study how both abiotic and biotic factors shape an organism’s distribution and behavior. These factors are essential to understanding why a species behaves or exists the way that it does.
Levels of Ecology
Ecologists study the effects of abiotic and biotic factors on multiple levels of life. These levels provide organization to nature.
• The biosphere is the broadest level and contains the entire Earth. An ecologist who is studying interactions at the biosphere level may be interested in the separation of the continents and climate change.
• The next level of ecology is the ecosystem. The ecosystem includes the abiotic and biotic factors in an interacting system. An ecologist studying the ecosystem would take note of how the abiotic factors make an impact on the organisms living within that ecosystem.
• The next level is the community level, which entails only the biotic factors in an interacting area. The ecologist that studies at this level may be concerned with predator-prey relationships.
• The next level is the population level. Population level ecologists are concerned only with interactions between members of the same species living in the same area.
• Lastly, the organism itself is a level. Ecologists may study the behavior of the individual or their specific physiology.
Behavioral ecology, a subset of ecology, focuses on animal behavior. Animal behavior can be broken down into two different categories. Innate behavior is behavior that is genetically encoded, and often is not conscious; reflexes, breathing, and instincts are examples. Learned behaviors are behaviors that result from learning due to experiences; conditioning and habituation are examples that are often described. There are many factors that animals use to dictate their behavior. There are cues that animals understand, such as daylight or pheromones, and they use these cues to make decisions regarding behavior.
Behavioral ecologists are also concerned with how animals parent their young. There are three survivorship curves that the AP biology exam may ask you about:
• Type 1 animals have a low death rate at the beginning of life and a steep death rate at the end of life,
• Type 2 animals are intermediate with constant death rates, and
• Type 3 animals have a high death rate at the beginning of life.
The survivorship curves tell us how much nurture we would expect an organism to give to its offspring. For example, if the organism is a type 3 animal, it may not use much energy to care for its offspring because the offspring has a high chance of dying.
Population ecology is another subset of ecology that focuses on how a population of animals is structured. Population ecology is focused on much more quantitative data, though you just need to know the key information for the AP biology exam. Population density is the number of individuals per unit area. Population ecologists use the population density to understand how the population disperses itself. There are three major patterns used by ecologists:
• Clumped is when the individuals are found in patches,
• Uniform is when the individuals are spaced out evenly, and
• Random is when the individuals appear to exist independently from other individuals in their population. This information can tell us about the individuals and how we should expect them to behave.
Community ecology is focused on how the abiotic and biotic factors of an environment shape the organism’s niche. A niche is an exact place that an organism fits into its environment; it involves feeding, defensive, and sexual behaviors. A species may exist within the same niche as another species which will cause interspecific competition.
Community ecology is also interested in the symbiotic relationships existing between species in a community. There are three major relationships that the AP Bio exam tests:
• Parasitism is when one organism (the parasite) is benefiting from the relationship while the other organism (the host) is being harmed,
• Mutualism is when both organisms benefit, and
• Commensalism is when one organism is benefitting and the other organism is not affected by their relationship. When organisms are involved in these relationships, it is possible for them to coevolve.
One final topic that is necessary to be familiar with is the trophic levels. Trophic levels are hierarchical levels in an ecosystem that portray how energy flows through the ecosystem. The trophic levels begin with producers (often plants) that produce energy from the sun. The following level is the organisms that eat the plants, which are called the primary consumers. Based on the ecosystem, the consumers can go as far up as necessary (secondary, tertiary, quaternary). With each movement up the trophic level pyramid, energy is lost, and an organism must eat more to get the same amount of energy. The primary producers get all of the energy from the producers.
The trophic levels set up predator-prey relationships that cause coevolution arm’s race. Prey evolves to outcompete their predators while predators evolve to outcompete their prey. An example of this comes from prey coloration and camouflage. Camouflage specifically refers to the coloration of an organism that causes the organism to blend into its surroundings. There are other types of coloration that can help an organism survive as well. These colorations signal to the predator that the prey is poisonous. If the prey is truly poisonous, it is called Mullerian coloration; if the prey is colored like a poisonous prey but is not poisonous, it is called Batesian mimicry.
Free Response Question
Now that we have both answered the question of what is ecology and reviewed the key information needed for the AP Biology exam in this AP Biology review, we will look at a question that appeared on the 2011 AP Bio Exam.
Question: Describe how adaptive coloration and mimicry act as animal defenses against predation.
Batesian mimicry and mullerian coloration assist prey in defending themselves against predators. An example of prey that uses this type of defense is snakes. Snakes that are poisonous are often colored red, yellow, and black to signal to predators that they are dangerous. There are also many mimics who are colored red, yellow, and black, but are not poisonous. The slight differences in their coloration often lead predators to assume that they are much more dangerous than they are.
Thank you for reading this article! Do you now know the answer to the question what is ecology? Do you have a suggestion to make these AP Biology reviews better? Leave us a comment below and let us know what you think! If you liked “What Is Ecology? An AP Biology Review” and want more, please try our AP Biology Review on DNA Replication!
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In evolution there are many trends that are seen whether it's divergent evolution where similar creatures become more different or convergent evolution when different species are becoming more similar. Different variant on this is something called coevolution and that's when two species influence each other's evolution. Now this is because each species exerts selective pressure on the other species. Some common examples of this include bees in flowers, wolves and rabbits, even HIV in humans.
If we take a look over here, here's a picture of a bee and you can see it on a flower. Now flowers are influenced by the bees because the flower that has the best combination of colors and the best nectar for feeding the bee, will attract more bees. and if they provide lots of nectar, then that bee will have lots of food, bring it back to the hive and wind up having lots of little baby bees which will mean in the next generation even more bees will be coming top this particular flower. now why would the flower want to attract bees? Well, that's because if you look at the hairs here you can see little yellow spots, those are pollen. These are the reproductive structures that this flower is using to fertilize other flowers of the same species and it's basically how flowers engage in sex. And so by bribing the bee, come here, come here, come here the bee comes along, picks up some pollen and then flies off and finds a similar flower, lands and when that pollen rubs off against the female part of this flower. That pollen pollinates the flower thus allowing sex between the flowers so that the plant can have lots and lots of seeds. so it's advantageous to the flower to be really good at attracting the bees. Now the bees are influenced because if you notice it has these hairs. Why does it have so many hairs and especially look at its legs are furry. Why do they have that? Well, that's what helps pick up the pollen. Now why would the bee want to bother picking up the pollen bee sides in its mouth? well, remember every time a bee pollinates another flower that makes seeds which makes more flowers which means more food for the bees. so the furrier the bee, the hairier the bee the better that hair is at picking up pollen, the better food supply in the future that bee will have. And so, the flower exerts pressure on the bees, the bes exert pressure on the flower.
Similarly, wolves exert pressure on rabbits and vice versa. Now not in this I'm going to give you food if you help me have sex kind of situation. But wolves catch rabbits. which ones do they catch most easily? the slow stupid ones. So that tends to make for faster smarter rabbits. But then, what happens to the wolves? Well, the lame wolves the wolves who get kind of easily confused by ooh, rabbit tree, what do i eat? Those will die making for smarter wolves and the slow ones die so the faster wolves. So they keep influencing each other in this evolutionary arms race.
Kind of a parallel thing is going on with us and HIV. HIV is evolving to get better and better at infecting humans and humans are people whoa re easily infected and die quickly, there genes are removed. There's already been discovered some individuals who have genetic predespositions that make them a little bit more resistant to HIV influences. And so if this continues, if we don't use our intellect and our technology to defeat HIV, then we may see eventually a slow evolutionary pressure on humans to become more resistant to HIV.