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In Australia, researchers tested the hypothesis that sea urchin abundance limits kelp distribution. Select the evidence that offers the best support for this hypothesis.

A. When sea urchins were removed from experimental plots, kelp cover increased.
B. Sea urchins graze on kelp.
C. There is an inverse relationship between the abundance of sea urchins and the abundance of kelp.

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Related questions

The investigator never begins an experiment without a prediction of its outcome. The prediction is always based on the particular experiment designed to test a specific hypothesis. Predictions are written in the form of if/then statements: "lf the hypothesis is true, then the results of the experiment will be…"; for example, "if cactus spines reduce herbivory, then removal of the spines will result in greater surface area removed by herbivores." Making a prediction provides a critical analysis of the experimental design. If the predictions are not clear, the procedure can be modified before beginning the experiment. For the soybean experiment, the hypothesis was: "Exposure to sulfur dioxide reduces reproduction." What should the prediction be? State your prediction.

To evaluate the results of the experiment, the investigator always returns to the prediction. If the results match the prediction, then the hypothesis is supported. If the results do not match the prediction, then the hypothesis is falsified. Either way, the scientist has increased knowledge of the process being studied. Many times the falsification of a hypothesis can provide more information than confirmation does, since the ideas and data must be critically evaluated in light of new information. In the soybean experiment, the scientist may learn that the prediction is true (sulfur dioxide does reduce reproduction at the concentration tested). As a next step, the scientist may now wish to identify the particular level at which the effect is first demonstrated. Review your hypotheses for the numbered questions. Consider how you might design an experiment to test the first hypothesis. For example, you might measure auditory function by performing hearing tests or observing changes in structures in the ear. The prediction might be:

IF cell phone usage reduces auditory function (a restatement of the hypothesis),

then people who use cell phones will score lower on hearing tests than persons who do not (predicting the results from the experiment).

Now consider an experiment you might design to test the second hypothesis. How will you measure "mental advantage"?

State a prediction for this hypothesis and experiment. Use the if/then format:

The actual test of the prediction is one of the great moments in research. No matter the results, the scientist is not just following a procedure but truly testing a creative explanation derived from an interesting question.​

1. Honeybees provide 80% of the pollination services for crops, including almonds, squash, melons, alfalfa, apples, and pumpkins. Migratory beekeepers transport over 2 million hives to farmland as crops begin to flower. In 2006-2007 beekeepers were alarmed when 50% of the honeybee colonies in 26 states were lost. In fact one of the biggest mysteries was that the bees were not found dead in the hives, but rather were simply gone! Scientists have termed this Colony Collapse Disorder (CCD). They are currently considering three alternative hypotheses: emerging pathogens (viruses, bacteria, and/or fungi), environmental toxins or chemicals; or abduction by humans (or aliens). Using the criteria in Lab Study B, Developing Hypotheses, select the hypothesis you would pursue as a scientist and justify your choice.

Lab Topic 1: The Process of Science

Introduction

1. Which of the following questions would you consider appropriate scientific questions that can be tested using the scientific method? For the statements that can be tested using the scientific method, explain how your experiment would be set up. Explain the different steps in the scientific method as they relate to this statement.

a. Does the pH of the soil affect the color of hydrangea flowers?

b. What properties of the soil influence the color of hydrangea flowers?

c. Do hydrangeas look more beautiful when grown in the right soil?

d. Was The Day After Tomorrow a better movie than Terminator?

e. Does grass require fertilizer in order to grow?

2. Read this hypothesis and answer the questions below:

Plants kept closer to windows grow larger than plants kept several feet away from windows.

a. Indicate the dependent variable:

b. Indicate the independent variable:

c. List 3 other variables that must be kept constant in this experiment (the control variables).

d. Write a prediction based on the above hypothesis.

Exercise 1.1

Take a Deep Breath

Students will need to take a picture of themselves or their group walking up and down on the step or doing other exercise. Include a note with your name and date on an index card in the picture. Insert picture here:

1. Identify the following in the experimental design. You will need to refer to the protocol to answer this question.

a. Independent variable:

b. Dependent variable:

c. Experimental dataset:

d. Control dataset:

e. Hypothesis:

2. Fill in the data for each individual in your group for the Breath experiment.

Length of time breath can be held (seconds)

Individual Tested

Resting

After 1 minutes of exercise

After 5 minutes of exercise

Average (take the average for each column)

3. Look at the averages for all individuals in your group. Was the hypothesis you stated in the previous question supported by the “average data”? Explain your answer!!!

4. Now look at the data for each individual separately. Was there data for anyone in your group that did not support the hypothesis? If yes, explain whythis could be.

5. How many replicates did your group have?________________ Why is it good to have more than one replicate?

Exercise 1.2

Let’s Graph

In this exercise, you will be graphing the data that you collected in exercise 1.1.

1. In exercise 1.1, you identified the independent and dependent variables. Which one goes on the X axis of the graph and which goes on the Y axis?

2. Will you make a line or a bar graph of your data? Explain why you chose this type of graph.

3. You will need to use excel to generate a graph of your data. On this graph, you will need to label the title, independent variable, dependent variable and possibly the legend. You will need to select an appropriate scale so the data is spread out on the graph.

*Consult with your instructor to see how he/she would like for you to submit your graph. You might work on it in class and submit it through D2L or you might submit it at a different time. If you are taking the online version of the class, you will need to use Excel or word to make the graph.

Exercise 1.3

You will need to get the data under exercise 1.3 in the protocol sheet to complete these sections.

1. What is the dependent variable?

2. What is the independent variable?

3. Which, if any, of these individuals has diabetes? ___A or B ___?

4. What data do you have to support your hypothesis?

5. Construct a graph showing the time after eating each group had the greatest blood glucose levels.

1.. Polymorphisms for a given trait are relatively common in most species. Discuss the possible advantages or polymorphisms in terms of evolutionary fitness. Be sure to relate your discussion to a specific example. It is also possible that organisms showing more heterozygosity may actually be less fit. Describe one such possible scenario.

2. In the peppered moth (Biston betularia), black individuals may be either homozygous (A1A1) or heterozygous(A1A2), whereas the pale gray moths are homozygous (A2A2). Suppose that in a sample of 250 moths from one locality, 108 are black, and 142 are gray.

3. Retrace the history of primate evolution from early primates to monkeys, apes and hominins. When did some ofthe significant divergences occur (such as between the prosimians and the monkeys or between the chimps and hominins)? What was happening with the continents and the major climatic conditions during these times?What are the major species (including the extinct species) along the human lineage after the split with the chimps and bonobos? Where did many of these events occur on the globe and when?

4. Spencer Wells described his study how the genetic markers in humans are being used to infer the historical geographical distribution of humans and the dispersal of our ancestors. Explain how the genetic markers on our DNA (from blood samples) helps us understand that history. What are the techniques he is using? What is the nature of the evidence? What are the major conclusions about the journey of our ancestors out of Africa?What were the major migrations of humans to all the other continents? Approximately when did each migration occur and what were the major paths? How does the evidence support these conclusions? What Supporting evidence besides the DNA evidence is being used to support these conclusions?

5. Provide an adaptive and a non adaptive hypothesis for the evolutionary loss of useless organs, such as eyes in many cave-dwelling animals. How might these hypotheses be tested?

6. Directional selection is one of the models of natural selection. Describe this type of selection in terms of the frequencies of advantageous alleles over time. What is the trend over time? What is the eventual outcome for this allele as long as no other evolutionary factors intervene? Describe at least one good example of directional selection.

7. Consider the first copy of an allele for insecticide resistance that arises by mutation in a population of insects exposed to an insecticide. Is this mutation an adaptation? If, after some generations, we find that most of the population is resistant, is the resistance an adaptation? If we discover genetic variation for insecticide resistance in a population that has had no experience of insecticides, is that variation an adaptation? If an insect population is polymorphic for two alleles, each of which confers resistance against one of two pesticides that are alternately applied, is that variation an adaptation? Or is each of the two resistance traits an adaptation?Explain your reasoning thoroughly.

8. Suppose that a mutation in a species of annual plant increases allocation to chemical defenses against herbivores, but decreases production of flowers and seeds (i.e., there is an allocation trade-off). What would you have to measure in a field study in order to predict whether or not the frequency of the mutation will increase?

9. In many socially monogamous species of parrots and other birds, both sexes are brilliantly colored or highly ornamented. Is sexual selection likely to be responsible for the coloration and ornaments of both sexes? How can there be sexual selection in pair-bonding species with a 1:1 sex ratio, since every individual presumably obtains a mate? Which of the models of sexual selection described in the book might account for these species characteristics?

10. Kin selection explains why organisms may provide benefits to relatives. Is there a conflict between the principle of kin selection and the evolution of siblicide and abortion?

11.Many species of albatrosses and other seabirds nest in colonies on islands. The adult search for food at sea,sometimes over great distances. Some ecologists who study seabirds turn to their favorite topic of discussion in a bar one evening, and one says, “I can imagine an albatross genotype that destroys the eggs of nestlings of its colony mates when the parents are away foraging, and leaves them dead without eating them. Do you think such a behavior would evolve?” One of his companions says, “Yes, because it would make more food available for the albatross and its offspring.” Another says, “No, because it would threaten the survival of the population.” The fourth says, “You’re both wrong. I have a different explanation for why albatrosses don’t kill others’ chicks.” What is the fourth ecologist’s explanation, and why does she think her companions are wrong?

12. The concept of a species is fundamental to understanding biology, yet there may not be one definition that fits all “types” of organisms (e.g. animals, plants, fungi, bacteria, slime mold, lichens, etc.). Discuss several of the definitions of a species as presented in class and present your own definition for a species. Compare the strengths and weaknesses of each definition. Ernst Mayr is strong proponent of the biological species concept.How does he justify his position? Do you agree or disagree? If we employ the biological species concept, when did species first exist? What were organisms before then, if not species? What might the consequences of the emergence of species be for processes of adaptation and diversification? Be sure to explain your reasoning thoroughly.

13. The process of speciation ultimately involves the development of reproductive isolation between two related populations of organisms. Describe the various types of both prezygotic and postzygotic reproductive isolation and give an example of each.

14. Respond to the following quote from the character named Mr. Spock in “Star Trek”:“A truly successful parasite is commensal, living in amity with its host, or even giving it positive advantages, as for instance, the protozoans who live in the digestive system of your termites and digest for them the wood they eat. A parasite that regularly and inevitably kills its host cannot survive long, in the evolutionary sense, unless it multiplies with tremendous rapidity ... it is not pro-survival.”From what you have learned in this course, do you agree or disagree with Spock? How can you apply your reasoning to the relative “fitness” of HIV which causes AIDS, the Ebola virus which causes hemorrhagic fever,fleas which suck blood from dogs, or the prokaryotic ancestors of mitochondria and chloroplasts?

15. In many species of birds and mammals, clutch size is larger in populations at high latitudes than in population sat low latitudes. Species of lizards and snakes at high latitudes often have smaller clutches, however, and are more frequently viviparous (bear live young rather than laying eggs), than low-latitude species. What selective factors might be responsible for these patterns? Explain your reasoning.

16. The popular media often presents evolution as being a predictable process with a definite goal. For instance, in one “Star Trek: Voyager” episode, the captain instructs the ship’s computer to extrapolate the “probable course” of evolution of hadrosaurs (a bipedal dinosaur), if hadrosaurs had been removed from Earth before the Cretaceous-Tertiary (K-T) Extinction and allowed to evolve on another planet. What information about the hadrosaurs’ new environment would have been useful in developing the best possible prediction? Given what you know on genetic drift and selective agents, is it possible to accurately predict the long-term course of evolution?

17. Young children often develop strong food preferences that sometimes seem bizarre to their parents --- such as wanting to eat only a certain food prepared in a familiar way, or being reluctant to each new foods or foods with strong or bitter tastes (like coffee and some vegetables). Develop an evolutionary explanation for such preferences. What evidence would you gather to investigate your hypothesis and rule out alternative explanations?

18. Many organisms, such as mammals, only reproduce by sexual means. Other organisms are exclusively asexual,such as many of the bacteria and fungi. And still others have ways of propagating by both sexual and asexualmeans. Discuss the relative advantages and disadvantages of each mode of reproduction. Why aren’t all organisms sexual critters? Why are many asexual organisms still very successful as evidenced by the pure abundance and diversity? What is the adaptive significance of having different genders (e.g. male and female)?In other words, why sex?

19. How might differential expression and regulation by Hox genes contribute to mosaic evolution in which different segments of an animal body plan evolve different morphology?

20. Development of a morphological structure involves many different types of gene products, including transcription factors, signaling proteins, and “effector” genes such as enzymes. When a morphological change occurs in a single mutational step, which of these types might be more or less likely to be involved? Within a gene, would such single-step events be more likely to involve coding or non-coding sequences, and what characteristics of the gene’s function might affect this likelihood?

21. Since 2001, the complete DNA sequences of the genomes of many people have been determined. If humans,along with other forms of life, have evolved from a common ancestor, what evidence of this would be expected in the human genome? In what ways might the history and processes of evolution help us interpret and make sense of the human genome sequence data?

22. Paleontologists and some biologists commonly infer function, and even behavior, from anatomical details.Skeletal features, for example, are often used to infer that an extinct mammal (such as an early hominid) was highly, somewhat, or not at all arboreal. This inference assumes a good fit of form to function (i.e., optimal form). Can this assumption be justified?

23. Stephen Jay Gould (1989) and others have argued that the evolution of self-conscious, intelligent species (i.e.humans) was historically contingent: it would not have occurred had any of a great many historical events been different. The philosopher Daniel Dennett (1995) and others have disagreed, arguing that convergent evolution is so common that if humans had not evolved, some other lineage would probably have given rise to a species with similar mental abilities. What do you think, and why? If Gould’s position is right, what are its philosophical implications, if any?

24. Explain how Intelligent Design was determined as a religious view rather than a scientific view in the court casein Dover, PA. Should a scientific explanation of evolution be included in a science curriculum in K-12 schools?How is science and religion different in how they seek answers to questions? How is term "theory" used differently in science than in everyday English use? What is biological evolution? What evidence is used to support the scientific explanation of evolution? Is it possible to accept scientific explanations without rejecting religious faith?

25. Discuss how a creationist versus an evolutionary biologist might explain some human characteristics and the implications of their differences. Sample characteristics: eyes; wisdom teeth; individually unique friction ridges(fingerprints); five digits rather than some other number; susceptibility to infections; fever when infected;variation in sexual orientation; limited life span.

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