Science and Ethics

Science and Ethics

Science and Ethics of Biology Chapter 1.

• Concepts discussed:

– Properties of living things

– Scientific process

• Hypotheses and Theories

– Experimental vs. naturalistic science

– Science and Society

– Biological Ethics

• Experimental subjects: computers, cells, animals and humans

• Science is not defined by subject matter but is defined by methods.

• Biology and the Living World

– The Diversity of Life

• Biology is the Study of living things.

• Living things can be categorized into six kingdoms:

– Archaebacteria, Eubacteria, Protista, Fungi, Plantae and Animalia.

• Biologists study the diversity of life in many ways:

– Observe behavior, study fossils and examine DNA.

– The Properties of Life

• Cellular organization: All living organisms composed of one or more cells.

• Metabolism: All living things use energy.

– How do organisms generate energy?

• Homeostasis: All living things maintain a stable internal environment.

• Reproduction: All living things reproduce.

• Heredity: All organisms posses genetic system for replication and duplication of DNA.

– Organization of Life

• Molecular level where the chemistry of life occurs.

• Organelle level where the cellular activities are organized.

• Cellular level the smallest organizational unit which can be considered alive.

• Cells with similar structure and function are organized into tissues.

• Tissues are combined into organs.

• Organs that carry out major body functions make up organ systems.

• Systems help make up the organism.

• Populations are organisms of the same type living together.

• Species are all the populations of the same organism.

• Community all the species that live in a single place.

• A community and the environment in which they live is an ecosystem.

– Biological Themes

• Evolution is the change in a species over time.

– Charles Darwin- English naturalist who proposed the idea of natural selection.

– Natural selection- Those organisms better able to respond to environmental challenges become more common.

– Diversity of life is due to natural selection.

• Flow of Energy through and ecosystem is a key factor in shaping that ecosystem.

– Plantsà Herbivores à Carnivores

• Cooperation between organisms has led to coevolution and is also responsible for the diversity of living things.

• Structure in biology is often closely related to function.

• Homeostasis has contributed to the specialization of organisms.

• The Scientific Process:

– The Nature of Science.

– A Hypothesis is formed from a series of observations.

• Must be either verifiable or falsifiable.

• Observations testing a hypothesis are called data

• Specific vs. General Hypotheses.

– A specific hypothesis is one that is easily verifiable and is not usually one used science because it tells us very little.

• Ex: The sun will rise in the east tomorrow.

– Easy to verify and relatively unimportant.

– Easy to verify because it is so (too) specific.

– A general hypothesis usually leads to continued testing in an attempt to falsify it.

• Ex: The sun will rise in the east every morning.

– Hard to verify because you must observe the sunrise every morning and a single occurrence of the sun not rising in the east falsifies the hypothesis.

– This often the type of hypothesis that science uses in that it is falsifiable but not completely verifiable.

• Falsified hypotheses are rejected and a new hypotheses are suggested.

– Could be a revision of the old hypothesis.

• If a hypothesis is not (falsified) rejected then you may want generalize (or extrapolate) the hypothesis.

– Ex: If a hypothesis was correct for mice then you may want to extrapolate that hypothesis to humans.

– The only way to know the extent of generalization for a hypothesis is to continue to test (try and falsify it) it under different conditions.

– Devising a hypothesis.

• Deductive reasoning is the reasoning of everyday thinking, uses logic not observation.

• Inductive reasoning is a way of discovering general scientific principles by careful examination or observation of specific examples.

– Scientists often use: Imagination, preference, philosophical ideas, comparison or serendipity.

– Ex: Alexander Fleming and the laboratory accident.

» Hypothesized a product of the fungi killed the bacteria.

– Einstein said that “imagination is more important than knowledge”.

– Science in Action a Case Study

• Joseph Farman (1985) observes 30% drop in ozone levels in the Antarctic atmosphere.

– Unexplained weather phenomenon?

• Evidence indicated that Chlorofluorocarbons (CFCs) reacted with ozone in the sun destroying the ozone.

– CFCs are used in coolants, propellants and foaming agents.

• Thinning ozone increases exposure to UV radiation.

• Ozone depletion continues and the hole over the north pole will cover the northern portions of the globe.

– Increased chlorine and fluorine.

• Stages of Scientific Investigation

– The steps of scientific discovery are called the Scientific Method.

– The scientific method uses statistical analysis to confirm hypothesis.

• Observation-

• Hypothesis-

• Predictions-

• Testing-

–

• Controls-

– Variable- Is a factor that might affect a process.

– How is this done?

• Conclusions- A hypothesis that has been tested and not rejected is tentatively accepted.

– A collection of related hypotheses that have been tested many times is called a theory.

– In order to tentatively accept a hypothesis certain things must occur.

» Their must be reproducibility of the results.

» The tests must be conducted many times and stand up to statistical analysis.

• Examining the Hole in the Ozone Layer.

– Observation- Farmen et al. had studied the skies over Antarctica for years. By keeping careful records he noticed the drop in ozone levels.

– Hypothesis- What is destroying the ozone?

• Environmental scientists guess that CFCs are to blame.

• Alternative hypothesis a guess that it was a transient phenomenon due to sunspots.

– Predictions- If the CFC hypothesis is correct then you should be able to detect CFCs in the upper atmosphere and also the byproduct chlorine.

– Testing- Scientists tested the CFC hypothesis.

• Atmospheric samples were collected from the stratosphere.

– Not only did the samples contain CFCs but also Cl and Fl.

– Supported the hypothesis.

– Controls- scientists reconstructed the atmospheric conditions.

• If ozone levels fell without CFCs being added to the chamber then CFCs could not be the culprit.

• There was however, no detectable drop in ozone until CFCs were added.

• This is consistent with the hypothesis.

– Conclusions- The hypothesis was tentatively accepted.

• Now the CFC hypothesis is is supported by a great deal of experimental evidence and is widely accepted.

• The theory of the ozone shield, that the ozone shields the earth from harmful UV rays by absorbing them is supported by a wealth of observation and experimentation and is also widely accepted.

• Using Science to Make Decisions

– Theory and Certainty

• A scientific theory is one that has withstood repeated observation and experimentation.

– The theory of gravity.

• A theory in common speech is different then in science.

• Theories may often shown in a mathematical or visual form called a model.

• Theories can be falsified by even further testing (falsification) or a more satisfactory model (explanation).

– Hypothesis testing and experimental science.

• Hypotheses are tested using experiments.

– Experiments are artificial (sometimes) situations set up by the investigator to test the hypothesis.

– Often experimental sciences ask “how does X work?”

– The investigator sets up the experiment to determine if the hypothesis is true than a certain outcome will occur.

» However often it is set up so just as much (or more) will be learned if the hypothesis is falsified.

– The results of the experiment are determined objectively.

» Means without bias for or against the hypothesis.

• Example: Joshua and Esther Lederberg’s experiments on streptomycin resistance of Escherichia coli (E. coli).

– Joshua Lederberg won the Nobel Prize.

– Streptomycin is an antibiotic that kills most bacteria.

– The researchers exposed the common intestinal bacteria E. coli to streptomycin and recovered strep. resistant bacteria.

– Allowed these resistant organisms to reproduce and showed that their offspring where also resistant to the antibiotic.

» A permanent genetic change.

• The resistance of these organisms gave rise to two hypotheses.

– 1) Mutation had been induced by exposure to streptomycin.

– 2) Mutation had occurred before exposure to streptomycin.

• Tested these hypotheses by using a method called replica plating.

– An apparatus to make copies of bacterial colonies.

• Which of these hypotheses was falsified?

– 1) Mutation had been induced by exposure to streptomycin.

– 2) Mutation had occurred before exposure to streptomycin.

• What would be the next step?

• Could this be extrapolated to other microbes? Antibiotics?

– Hypothesis testing in naturalistic science.

• Direct experimentation is impossible or undesirable.

– Ex: Animal behaviorist wants to study mating behavior in a certain species observations can be made hypotheses can be generated but experimentation is undesirable.

– Ex: astronomy. Why?

•

– Ex: Mitochondrial DNA is almost never inherited from the father .

» Rebecca Cann and her associates studied Mito. DNA and were able to link populations to common ancestors

» Also have data consistent with all human populations being descended from an ancestral African population.

» And everyone a descendant of a single common female ancestor in Africa this is called the “Eve hypothesis”.

» This explains present populations on the basis of their past history.

• Revolutionary Science vs. Normal Science.

– Normal science is the piecemeal discovery of and accumulation of new but small findings.

• Normal science is channeled by channeled by a paradigm.

– A paradigm is more than a theory it is based in the truth of one or more theories.

– A paradigm tells what problems are important and worth investigating and which techniques are and methods are most useful.

• Once in a great while science proceeds differently through a scientific revolution.

– As a result an old paradigm is discarded and a new paradigm is adopted this is called a paradigm shift.

– The introduction of Molecular Genetics was a result of a paradigm shift.

» Molecular genetics (molecular biology) emerged following the discovery of the structure of DNA in 1953 by James Watson and Francis Crick.

» This led to the central dogma of molecular genetics that DNA is used to generate RNA which in turn is used to generate a protein.

» Brought new cellular process to light: replication (copying DNA), transcription (DNA -> RNA), translation (RNA -> Protein).

• Science cannot explain every fact of life nor can it solve all problems.

– Supernatural, religious and unexplained phenomenon cannot be studied.

» Cannot be scientifically studied, analyzed or explained.

– Cannot restore an extinct species.

• Very active areas of science are often alive with controversy.

– Ex: Prions.

• Is science something only those in science can do?

– Science is a community.

• Scientists use results from one another in order to formulate and test new hypotheses.

• It is not a solitary discipline.

• Scientists continually retest their own as well as others hypotheses.

– Ex: Galileo would often encourage people who disagreed with his hypotheses to look through his telescope.

– Isaac Newton said “ If I have seen further than others gone before me, it is because I have stood on the shoulders of giants.”

• Science and Ethics

– Science itself can not always tell us whether certain research should be done or how certain results should be used; for those answers we turn to a discipline of philosophy called ethics.

– We all use our own beliefs to make decisions throughout the day these are morals.

– Moral decisions are sometimes made with a knowledge that society may punish our actions.

– The analysis of moral rules is part of the discipline of ethics.

– Ethics: normative and descriptive ethics.

• Normative ethics

– Is a theoretical discipline rooted in logical analysis.

– Doesn’t use data for no data can refute moral laws such as “thou shalt not kill”.

– Simply normative ethics is an attempt to reduce moral codes to a set of basic rules

• Descriptive ethics

– Studied by observing human behavior by using the scientific method.

• Are there situations when moral rules need to be bent or ignored?

– Types of ethical systems.

– Deontological system: Says the rightness or wrongness is in the act itself not how it effects society.

• Often the moral code based on sacred texts.

• The rights ascribed by many deontological systems have resulted in mistreatment of certain classes of individuals as well as atrocities due to adherence to a single principle above others.

– Utilitarian system: Acts are judged by there consequences

• Act utilitarianism looks at each act on a case by case basis.

• Rule utilitarianism uses general rules to judge acts with an occasional place for exceptions.

• Problems with utilitarianism is that overall good outshines the good for a single person which can lead to killing one innocent person leading to the overall good for society.

– Policy decisions involving science can be broken into three phases.

• Scientific issues: An analysis of what hypothesis best fits the available data.

• Science policy issues: What are the consequences of this action? Political, economic and scientific.

• Policy issues: Risk to lives spending billions, is it worth it? Is the social cost worth the benefit.

– Once policy decisions are made by the public, politicians and scientists then you can use that information in directing your investigations.

• Ethical questions arise when using experimental subjects.

– Scientists must sometimes use animals and human test subjects in their research.

– Uses of animals.

• Most societies use animals in agriculture for food and pets.

• Use of animals and love of animals can go hand in hand.

• Animals are used in research although the number is small compared to other uses.

• Most people agree that animals are necessary stand ins for humans in medical research.

• Most people (scientists included) agree that these animals need to be well-treated and not to suffer.

• The U.S. guide for the Care and Use of Laboratory Animals reflects that concern.

– There are strict standards that scientists must follow and these are enforced at all research campuses and companies.

– All research on animals (and humans) must be Ok’d by a ethics advisory panel before it can proceed.

– Animal rights.

• Groups involved in animal rights range from the humane society (SPCA), PETA and the animal liberation front (ALF).

• Some of these groups like the society for the prevention of animal cruelty work through legislation in part with scientists to ensure animal welfare.

• Some groups like PETA tend to spout misinformation and more radical groups like ALF have been involved in terrorist actions.

• Do animals have rights? If so how far do we go in protecting the rights of living things?

• Do we need to do research on animals at all?

– Humans as test subjects.

• After research has gone through many phases of testing including animal a fraction of research can go on to human clinical trials or human tests.

• Human testing avoids compatibility problems faced with animal research.

• Obviously there are more objections to exposing human subjects to potential risks.

• Voluntary informed consent- Humans can consent to testing while nonhuman animals cannot.

– However this consent must be voluntary, which is a legal and moral issue.

– The test subject must be aware of all possible positive and negative results of the testing.

– Usually obtained by a form signed by the individual outlining the procedure as well as risks (this is informed consent).

– Special questions arise when a person does not have the full capacity to understand the risks.

» Ex: children, mentally deficient, comatose etc..

– Most now would agree these people can not give informed consent and it would be unethical to use them as test subjects.

» It has not always been this way.

» Parents do have the legal (moral?) right to make these decisions for there children.

» What about prison populations?

• Guidelines for experiments on Humans.

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» Before the 1990’s all tests were done on male subjects with the reason being to avoid a women’s hormone fluctuations from her menstrual cycle.

» Dr. Bernadette Healy of the National Institutes of Health (NIH) worked to change this.

» Now all studies must be done on males and females where appropriate.

• Discussion Questions:

– Which of the following are experimental tests? Naturalistic observations?

• Measurements made on the bones of an extinct species are compared to related living species.

• Activity of the white blood cells of a rat compared to those of a stressed rat.

• A group of animals fed a suspected carcinogen to see if they get cancer as a result.

• A list of species found in one location compared to a list of organisms found in another.

– Is it ethical to infect a few people with a deadly disease in order to save millions in the future? Why? How would a deontological or utilitarian ethicist argue?

– How accurately can results be extrapolated? How about results from an inbred male rat to a human? A human female? What are some ethical issues involved?