Why Are There So Many Butterflies?

Understand how the diversity in an ecosystem and the adaptation of organisms to an ecosystem relates to structures and their functions in living organisms. Natural selection helps explain the diversity of life.

Diversity and Adaptation

We hear a lot about diversity in our society. We understand diversity in humans to mean how we speak different languages, eat different foods, have different value systems or how we look different. Many types of scientists study diversity, like anthropologists who study social relationships, linguists who study languages, and dieticians who study nutrition. Biologists are mostly concerned with the genetic diversity between populations. When we consider biomes, now we’re concerned with the diversity among populations in an ecosystem.

What does this all mean? Well, different populations make different adaptations to their environment. If we’re studying the tundra, all living things need to deal with the cold. A polar bear will gain more fat in order to keep its heat inside; an arctic fox will keep warm blood from reaching its feet so that it doesn’t lose heat to the ground; shrubs will grow a protective coating around their stems to protect them from low temperatures and high winds. All of these adaptations allow these living things to live in the tundra.

You can see how diversity and adaptations are linked together: organisms find diverse ways to adapt to their environments. We can even introduce another concept that we’ve learned, natural selection! The organisms that are able to adapt better to their environment survive better, which means that they are more likely to reproduce.

If we go back to the example of the butterflies and birds, it’s completely possible that there were no blue and black butterflies a few weeks before we visited the field. It’s very likely that among the thousands of butterflies, some mutations will happen: one of them happened to change the color of the butterfly from yellow to blue. This caused the butterfly population to have higher diversity. When birds started to hunt the yellow and black butterflies, the population adapted to the change in the environment by favoring the blue and black butterflies. Natural selection happened when those blue and black butterflies reproduced, eventually making more that had the same coloring!

1. How are diversity and adaptation related?
2. Explain natural selection using terms from this chapter.
3. Define biological diversity in your own words.
Put it together
4. Choose an animal that you are familiar with. Explain how different populations of this animal are diverse, in three ways.
5. Select a biome and a living thing. What sorts of adaptations has this living thing made in order to survive in this biome?
Think about it
6. Do “T-Shirt Art” for the topic: diversity.
7. In your own words, define photosynthesis, chemosynthesis, respiration and fermentation.
8. List at least five different types of precipitation (you need to come up with one of them on your own).
9. Define the four major roles of the biotic part of the ecosystem in your own words.
10. Calculate the gene frequencies if there were 150 yellow and black butterflies and 100 blue and black butterflies in the field.
Natural Selection and Animals
  1. Take an animal card from http://researchparent.com/wp-content/uploads/World_Zoology_2-Part_Cards.pdf . Name 3-5 characteristics (that you can see, or that you read about) that make this animal unique.
  2. What environment is this animal usually found in?
  3. Explain two advantageous characteristics that the animal has which makes it fit for its environment.
  4. Choose any other environment. What are some advantageous characteristics that the animal would have in this foreign environment?
Build Your Own Ecosystem, Part 2

You will use your ecosystem from part one that you created. If you did not create an ecosystem, find a location for your ecosystem (it can be anywhere) and name three biotic factors (living things) in your ecosystem. Assume that your ecosystem is the size of Forest Hills to do the following:

  1. Talk to two people and ask them for a natural disaster which could happen in your ecosystem. For each:
    1. Write down their name
    2. Write down the natural disaster
    3. Predict what would happen to the carrying capacity of each of your three biotic factors due to this natural disaster. Assume that some living things are capable of surviving this natural disaster!
  2. Make a food web for your ecosystem. Add enough biotic factors so that you get a total of at least 8 organisms, including producers, primary consumers and secondary consumers!
Adaptive Radiation

For this activity, you will be pretending to be a bird that is trying to get food. The scenario is that you and all of the other “birds” in the class end up on a deserted island. It is a large island, and every “area” (desk) has a different type of food and can support a different number of birds. You are given a choice of “beaks” (tool) and you have to figure out which is the best area for you to settle. You have five minutes to locate an area and a beak that you think will maximize your chance for survival. Try “eating” different seeds with different beaks. At the end of five minutes, we will total up the birds in each area, and make note of the beak that each bird has chosen.

  1. Which area and tool did you choose? Why?
  2. Would you have survived? Why or why not?
  3. What is adaptive radiation?
  4. How did this exercise demonstrate adaptive radiation?
  5. What would have happened if all of the seeds had been the same?
  6. Give an example of adaptive radiation in a living thing that you are familiar with.
Build Your Own Creature

Creature & Environment Cards

In this activity you will construct imaginary creatures and environments from the lists of characteristics. Be creative since these creatures and environments do not have to behave like anything here on Earth.

  1. Obtain a creature card from your teacher, then make a single choice from each of the 6 creature characteristics.
  2. Once you have made all your choices, fill out your creature card (including a name for your creature) and put it in the class creature box.
  3. Repeat this process two more times to construct two more creatures. Make sure you create significantly different creatures each time.
  4. Obtain three environment cards from your teacher then create an interesting environment. (Note: The environments you create in no way need to match the creatures you have already created.)
  5. Record your choices on your environment card and then put it in the environment box.
  6. Repeat this process two additional times, making sure that each environment you create is different.
  7. Once every group has finished, draw a single creature card and a single environment card from each box. This will be your first creature/environment pair to study. Once each group has drawn their first pair, each group will draw a second creature/environment pair. Repeat this process again so that each group has a third creature/environment pair.
  8. Your group should now have three creature/environment pairs to study. In this portion of the activity, we want to determine the success of each creature in the environment with which it was paired. To do this we will compare each creature characteristic and environment characteristic one pairing at a time. To score your creatures, use the following set of rules.
    1. Award one point if the creature characteristic helps your creature survive in that environment. For example, if the creature characteristic chosen from group #1 is “uses methane gas” and the corresponding environment characteristic from group #1 is “methane gas”, then your creature will earn one point.
    2. Award zero points if the creature characteristic and environment characteristic have no effect on your creature’s success. For example, if the creature characteristic chosen from group #6 is “has the ability to dig” and the corresponding environment characteristic chosen from group #6 is “multi-colored terrain”, then your creature will earn zero points.
    3. Subtract one point if the environment characteristic restricts your creature’s ability to survive. For example, if the creature characteristic chosen from group #1 is “uses oxygen” and the corresponding environment characteristic from group #1 is “carbon dioxide gas”, then your creature will lose one point.
  9. Score each pair of creature and environmental characteristics. Once you are done, record the total score, the creature and the environment.
  10. Would you rate the creature with the greatest score as having been very successful, moderately successful, or not successful in its environment? Describe the success or failure of the interaction between the creature and its environment for each set of characteristics.
  11. Give an example of an organism found on Earth that has a unique characteristic which makes it specifically suited to live in a particular habitat.
  12. Sometimes the characteristic that an organism has that makes it successful in its natural environment becomes useless when the organism is placed in another environment. Describe a real creature and environment found on Earth that would be an example of this situation.
  13. What one change would you make to your creature to make it more successful in the environment with which it was paired? Explain why you chose to make this change. If you feel no changes are needed for this creature, choose one of your less successful creatures to answer this question.
Benthic Invertebrate Identification

Stonefly Nymphs (PlecopCourtesy of the Cacapon Institutetera) | Long thin antenna project in front of the head; wing pads usually present on the thorax but may only be visible in older larvae; three pairs of segmented legs attach to the thorax; two claws are located at the end of the segmented legs; gills occur on the thorax region, usually on the legs or bottom of the thorax, or there may be no visible gills (usually there are none or very few gills on the abdomen); gills are either single or branched filaments; two long thin tails project from the rear of the abdomen.  Stoneflies have very low tolerance to many insults; however, several families are tolerant of slightly acidic conditions.

Courtesy of the Cacapon InstituteCaddisfly larvae (Trichoptera)  | Head has a thick hardened skin; antennae are very short, usually not visible; no wing pads occur on the thorax; top of the first thorax always has a hardened plate and in several families the second and third section of the thorax have a hardened plate; three pairs of segmented legs attach to the thorax; abdomen has a thin soft skin; single or branched gills on the abdomen in many families, but some have no visible gills; pair of prolegs with one claw on each, is situated at the end of the  abdomen; most families construct various kinds of retreats consisting of a wide variety of materials collected from the streambed.

Beetles (Coleoptera) | Head has thick hardened skin; thorax and abdomen of most adult families have moderately hardened skin, several larvae have a soft-skinned abdomen; no wing pads on the thorax in most larvae, but wing pads are usually visible on adults; three pairs of segmented legs attach to the thorax; no structures or projections extent from the sides of the abdomen in most adult families, but some larval stages have flat plates or filaments; no prolegs or long tapering filaments at the end of the abdomen.  Beetles are one of the most diverse the insect groups, but are not as common in aquatic environments.

Water Penny (Coleoptera)

Riffle Beetles (Coleoptera)

Beetle Larvae (Coleoptera)



Courtesy of the Cacapon Institute

Courtesy of the Cacapon Institute

Mayfly Nymphs (Ephemeroptera)    | Wing pads may be present on the thorax; three pairs of segmented legs attach to the thorax; one claw occurs on the end of the segmented legs; gills occur on the abdominal segments and are attached mainly to the sides of the abdomen, but sometimes extend over the top and bottom of the abdomen; gills consist of either flat plates or filaments; three long thin caudal (tails filaments) usually occur at the end of the abdomen, but there may only be two in some kinds.

Courtesy of the Cacapon InstituteDobsonfly Larvae & Hellgrammites ( Corydalidae ) | Head and thorax has thick hardened skin, while the abdomen has thin soft skin; prominent chewing mouthparts project in front of the head; no wing pads on the thorax; three pairs of segmented legs attach to the thorax; seven or eight pairs of stout tapering filaments extend from the abdomen; end of the abdomen has either a pair of prolegs with two claws on each proleg, or a single long tapering filament with no prolegs.

Gastropoda (Snails) | Operculate snails have a flat lid-like structure called an operculum that can seal the body of the snail inside the shell; the whorls of the shell bulge out distinctively to the sides (inflated); most have their opening on the right when the narrow end is held up; shells often extended into a spiral shape.  Non-operculate snails have no operculum; the whorls of the shell do not distinctly bulge out to the sides; often the shells of most kinds are shaped like a low flat cone or coiled flat instead of being extended in a spiral shape.  Typical size range for most snails is VS-L, which includes the shell.

Pouch & Pond Snails (Gastropoda)

Gilled Snails (Gastropoda)



Crustacea (Crayfish, Shrimp, Scuds and Sowbugs) | More than three pairs of legs (> 6) attached to the thorax; the first several pairs of legs may have a hinged claw, which is often enlarged as in the order Decapoda; bodies strongly flattened from top to bottom or from side to side; abdomen consists of individual segments or the segments may be fused to form a thoracic shield; some kinds have a broad flipper on the end of the abdomen.

Crayfish (Decapoda)

Sowbugs (Isopoda)

Courtesy of the Cacapon Institute


Courtesy of the Cacapon Institute

Dragonfly Nymphs (Anisoptera) & Damselfly Nymphs (Zygoptera) | Dragonflies: Lower lip (labium) is long and elbowed to fold back against the head when not feeding, thus concealing other mouthparts; wing pads are present on the thorax; three pairs of segmented legs attach to the thorax; no gills on the sides of the abdomen; Dragonflies have three pointed structures may occur at the end of the abdomen forming a pyramid shaped opening; bodies are long and stout or some- what oval.  Damselflies have three flat gills at the end of the abdomen forming a tail-like structure and their bodies are long and slender.

Courtesy of the Cacapon Institute

Clam (Bivalvia) | Two shells opposite of each other and strongly connected by a hinged ligament; the shell is thick and strong or thin and fragile in some kinds; growth rings on the shell are either far apart and are distinctly raised, or very close together and hardly raised at all; the foot usually consists of two tubular structures that can often be seen protruding from the shell; the body is soft tissue, often pinkish or gray in color.


On a separate sheet of paper, identify which invertebrate family(ies) could possibly match the following descriptions:

  1. Has six legs on the thorax, two long antennae and two long projections on the rear of the abdomen

  2. Has ten legs, including two claws attached to the front of the thorax

  3. Body is contained within shell that is whorled

  4. Has six legs on the thorax and three antenna-like filaments on the rear of the abdomen and a slender body

  5. Has six legs on the thorax and a disc-shaped body

  6. Body is contained within a shell that has rings

  7. Has six legs on the thorax and eight pairs of leg-like structures attached to the abdomen

  8. Has six legs on the thorax and three antenna-like filaments on the rear of the abdomen and a body that expands at the thorax

  9. Has six legs on the thorax and a body covered with stones from the bottom of the stream