Key Elements of the Nature of Science
NOS Lesson Selection Matrix
STEM, NGSS, CCS Features of ENSI lessons
Teaching Tips for Teaching NOS
NGSS NOS Standards Matrices
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Geological/Paleontological Patterns: General
- GEOLOGICAL-AGE CRITICISMS: TWO RESPONSES
- Date a Rock
- DEEP TIME
- Varve Dating
- Time Machine
- Patterns in Time: Experience Deep Time & Vertebrate Fossil Patterns
- 13 Ways to Tell Time Backwards
- The Great Fossil Find (NoS)
- Footsteps in Time (Laetoli Trackway) (ML)
- Laetoli Puzzle
- Lengthy Relationships (ML)
- Teaching About Evolution & Special Creation (ML)
- Virtual Age Dating Tutorial (off-site)
- Understanding Geological Time (UCMP - off-site)
- Explorations Through Time (UCMP - off-site)
(a series of interactive modules exploring history of life on earth)
Human Evolution Patterns
- Skulls Lab: Hominid Cranial Comparison
- Chronology Lab (ML)
- Comparison of Human & Chimpanzee Chromosomes
- Chromosome Connection 2
- Chromosome Fusion
- Mystery of the Matching Marks (Telomere DNA)
- Molecular Sequences, Primate Evolution & Cladistics
- Footsteps in Time (Laetoli Trackway) (ML)
- Laetoli Trackway Puzzle
- Classroom Cladogram of Vertebrate/Human Evolution
- Primate Classification (nested boxes) (ML)
- Teaching Evolution through Human Examples (AP Bio)
Classification, Hierarchy, Relationships
- Making Cladograms
- Molecular Biology & Phylogeny (Cytochrome C)
- Why Cladistics? (ML)
- What, If Anything, Is A Zebra? (ML)
- Cladistics Is a Zip...Baggie (ML)
- Nuts & Bolts: Is Classification Arbitrary - or Not? (ML)
- Tutorial: Investigating Evolutionary Questions Using Online Molecular Databases
- What did T. rex taste like? (UCMP lesson)
Adaptations, Imperfections, Contrivances
- Contrivances: Orchids & the Panda's Thumb (ML)
- Blocks & Screws: An Exercise in Contrivances
- Why Don't Whales Have Legs?
Variation and Natural Selection
- Born to Run: Artificial Selection Lab
- Natural Selection: A Cumulative Process (ML)
- Chaos & Order: Non-Random v. Random Events
- Natural Selection of Stick-Worms
- The Natural Selection of Bean Hunters
- The Chips are Down: A Natural Selection Simulation
- What Darwin Never Saw (ML)
- Origami Birds (ML)
- Galapagos Origami Bird - Its DNA ConnectionNEW
- When Milk Makes You Sick (Mini-Lesson)
- Lamarck vs Darwin: Dueling Theories (ML)
- A Step in Speciation (ML)
- Island Geography and Evolution: A Lizard Tale
- Quick Speciation Activity
- Microevolution to Macroevolution (Presentation)
- Video: What Darwin Never Knew (ML)
- Macro-Evolution: Patterns & Trends (ML)
- A Peek at the Past: Fossil Patterns (ML)
- Model Choices: What Happened to Dinosaurs? (ML)
- Becoming Whales: Discovery and Confirmation
- Whale Ankles and DNA
- Case of the Threespine Stickleback
- Pseudogene Suite, Part A: Why Vitamin C Is Needed In Our Diet
- Pseudogene Suite, Part B: Pseudogenes & Common Ancestry
- Pseudogene Suite, Part C: Primate Pseudogenes & Biology Workshop
Students get simulated "rock samples" which show a "highly magnified" selection of 128 atoms, each sample with a different proportion of the atoms of two different elements: a parent radioisotope, and its daughter product. By counting the parent radioactive atoms and knowing the "half-life" of those atoms, students can figure the number of half-lives since the sample solidified, and therefore the "age" of the sample. This makes a good introductory activity to the Deep Time lesson.
This lesson should effectively and accurately inform students about the high level of confidence we have in the geological ages of an old Earth. At the same time, it should reveal an example of pseudoscience which should be part of any effort to improve science literacy and critical thinking.
Students are taken through a combination of some background information and interactive experiences, and checked frequently by questions to confirm understanding. The narrative includes concepts of isotopes, radioactive decay, half-life, mineral formation, age analyses, fair test questions, and isochrons. The lesson can be used as a one-day team activity, individually in class, or as a self-teaching homework assignment. It is intended to either stand by itself, or to serve as an introduction to the very effective online interactive Virtual Age Dating Tutorial. This lesson would be helpful in Biology, Earth Science, Physical Science, Physics, Chemistry, or Geology classes.
Students count the number of varves (annual layers of sediment) in shale billets, taken from the Green River Formation in Wyoming. The count is then extended to reflect the entire 260 meters of sediments where the billets originated, a period of nearly 2 million years during which the annual lake sediments (varves) were laid down. This provides a vivid tangible experience to see real data first hand showing the passage of at least nearly 2 million years for the existence of a large lake, in contrast to a traditional view that the entire Earth is only about 6-10 thousand years.
This excellent online timeline gives students the "Big Picture" , ties everything together, from the Big Bang to the present. Directions and images suitable for all major events in time are downloadable so they can be copied and made available to your students to build. Scale is 1 mm = 1 million years. You have the option of starting at the Big Bang or the beginning of the solar system. Developed by Thomas Atkins (ENSI '92) and student.
Students are taken on a simulated "voyage" backward in time, to the beginning of our planet. They will "witness" that beginning, the origin of life, and a number of key events from then to the present. This becomes a dramatic experience, involving body and mind, helping students to relate physically at least to the relative timing of events in geological and biological history, if not to the absolute vastness of that time.
Students explore different ways gelogical time can be measured: comparing the time dimensions for each method, the mechanisms of each method, and the materials used
Students are taken on an imaginary fossil hunt. Following a script read by the teacher, students "find" (remove from envelope) paper "fossils" of some unknown creature, only a few at a time. Each time, they attempt to reconstruct the creature, and each time their interpretation tends to change as new pieces are "found".
Paleontologists occasionally find ancient tracks...footprints...preserved in the rocks. This lesson opens the door to analysing footprints, and gleaning information about body size and activities of the extinct animals that made the tracks.
A recent article in the ABT Journal by Anton Lawson presents a clever and interesting activity which provides vivid experience in the Fair-Test approach scientists use to determine the "Best Explanation". Students study a representative collection of fossils from the total geological column, look for patterns of fossil distributions, and raise testable questions about which idea (spontaneous generation, special creation, or evolution) best explains the origin of life's diversity and is consistent with the patterns observed in the fossil record.
VIRTUAL AGE DATING (off site; not an ENSI lesson)
Radioactive Decay Concept,
Isochron Dating Concept
Radiocarbon Dating Concept
Don't miss this excellent tutorial for teaching these three aspects of geological age dating. Each part is totally interactive and animated. Check questions are asked along the way to assess understanding. The final phase of the two dating concept routines provide an opportunity to simulate data collection and analysis. Those who complete a tutorial will have a real sense of achievement and understanding (and will receive a certificate!). Therefore, this online-interactive could be assigned as homework (optional or otherwise - if all students have internet access..
PATTERNS IN TIME: Experience Deep Time & Earliest Fossils
Students gradually build a realistic sense of deep, geological time from familiar linear analogs, e.g. calendars and football fields. They also learn to associate the earliest fossils of specific groups of vertebrates with the geologic time of their emergence, on the now-familiar scale of relative distances from their school. From this, they discover the pattern of gradual vertebrate emergence and how well it consistently fits vertebrate phylogeny.
Students describe, measure and compare cranial casts from contemporary apes (gorillas and chimpanzees, typically), modern humans and fossil "hominins" (erect and bipedal forms evolutionarily separated from apes). ("Hominoid" is the collective term for apes and humans.) The purpose of the activity is for students to discover for themselves what some of the similarities and differences are that exist between these forms.
Students plot the times of existence for the several species of hominins on a two-dimensional time line chart.
The banding patterns seen on stained chromosomes from humans and chimpanzees are compared in detail, showing striking similarities. Possible evolutionary relationships are explored, as are the chromosomes and relationships of other apes.
Students are taken on a chromosome comparison "adventure", in which the banding patterns are compared on the chromosomes of humans and apes. Degrees of similarities, and some causes of their differences are explored. Inferences about common origins based on those similarities (like forensic bullet marks) are also examined in a compelling way.
The banding pattern of our long chromosome #2 closely matches the banding patterns of two shorter chromosomes found in apes. This suggests the likelihood that our #2 chromosome was formed by the head-to-head fusion (merging) of those two shorter chromosomes in an early human ancestor. To test that hypothesis, students search for evidence of this fusion in the DNA of chromosome #2, using online databases (or printouts of same) to seek the sequences typical of terminal DNA (telomeres). In the process, students see how patterns can reveal events of the past, thereby merging elements of both experimental and historical science. They discover the huge amount of DNA in a chromosome, get a sense of gene size and the number of pseudogenes, correlate visible chromosome bands and their contained DNA, and learn to use an accessible resource for further study and inquiry.Modern apes and humans evolved from a common ancestor
This is a molecular probe into human evolution with a forensic flair. When bullet marks from bullets at a crime scene match bullets fired from a suspect gun, this provides compelling evidence of a common origin of the bullets - from the same gun. The same comparison of chromosome banding patterns of the chromosomes from humans and chimpanzees likewise offers compelling evidence of a common origin - a common ancestor. Furthermore, the existence of two shorter chromosomes in chimps that together closely match the long human chromosome #2 suggests the hypothesis that our #2 chromosome formed by the fusion of those two shorter chromosomes after we branched off from that common ancestor. Students test that hypothesis by searching for telomere DNA in the supposed fusion area of our #2 chromosome, and find it! This lesson includes a PowerPoint presentation that orchestrates the above series of experiences: background, preparation for the short lab, and follow-up. It also provides a somewhat more accessible version of the ENSI lesson: "Chromosome Fusion," where students actually search online DNA databases for the telomere sequences.
This lesson is roughly equivalent to the climax phase of the activity that accompanies the WGBH NOVA production "Judgment Day: Intelligent Design on Trial" (first aired 13 November 2007). In that trial, testimony by Prof. Ken Miller includes the chromosome fusion evidence that this lesson explores. In that activity, several different lines of evidence for common ancestry are examined, and students experience the compelling effect of accumulating that evidence, seeing how multiple lines of evidence provide a high level of confidence in their conclusion: that humans and chimps share a common extinct ancestor.
Students compare differences in amino acids in the beta hemoglobin from representative primates, complete a matrix of those differences, and from these data, construct and interpret cladograms as they reflect relationships and timing of divergence. Developed by Craig Nelson and Martin Nickels.
The 3.6 million year old tracks of an early hominin ("Lucy") in Laetoli provides a tantalizing opportunity to explore how scientists use patterns of the present to understand the past. What do those footprints tell us? How can we find out? Students measure and corelate their foot lengths and body heights, then use these data to estimate tallness of this Laetoli hominin.
Footprint diagrams were made from the trackway of Australopithecus afarensis ("Lucy's" species) at the Laetoli site in East Africa. They are topographic in nature, showing details of depth and superposition. Students are asked a series of probing questions, some requiring direct observation, others expecting inferences and analysis. This is an excellent example of an historical problem-solving exercise, using clues to derive a likely picture of a past event, very much like crime scene scientists must do. It's also open-ended, where students try to reach a "best explanation" based on the data and reasonable interpretations, with no "correct answer" available.
Students prepare the components for building a Colossal Classroom Cladogram of vertebrate evolution, then put it together, showing the gradual, mosaic accumulation of all of the traits which we, as humans, possess. A major purpose of this is to dramatize the evidence that we (and in fact all living things) didn't suddenly pop into existence, but clearly evolved as an accumulation of traits over vast periods of time. A follow-up discussion helps focus on these concepts.
Teaching Evolution through Human Examples
For AP Bio: Excellent collection of free units developed by the
Smithsonian Institution’s National Museum of Natural History.
CLASSIFICATION, HIERARCHY & RELATIONSHIPS
Classification can (and should) be used to illustrate more than a mere hierarchical grouping of organisms. This lesson introduces students to the building of cladograms as evolutionary trees, showing how "shared derived characters" can be used to reveal degrees of relationship.
Amino acid sequences in cytochrome-c are compared for several different animals, and the number of differences found are used to infer degrees of relationship. These data are also compared with a cladogram constructed for those same animals from their anatomical features, providing an example of independent confirmation.
This is an easily understood article which explains what cladistics is, why it is useful, how it is applied, and its limitations.
The essay (and reading guide) addresses the issue of cladistics, and some of the problems encountered in the science of Systematics.
A series of nested plastic bags is used as a 3-dimensional Venn diagram to illustrate the hierarchical grouping of organisms based on their shared derived characters, thus forming the basis of a cladogram.
Students working in teams classify furniture, share their categories and rationales, then note how their different schemes vary, perfectly logical and useful, but completely arbitrary. They then see how living organisms are classified, and note how these groupings are natural, nearly always reflecting the same ancestral relationships in nested hierarchies, regardless of the deeper criteria. Such patterns are revealed with a look at several phylogenetic trees of primates. Finally, teachers are encouraged to give their students lab experience collecting data from a variety of primate characteristics (skulls, chromosomes, and hemoglobin), to see for themselves the congruency of those data sets. Based on NABT session by Martin Nickels
Students transfer examples (names) of primates from their location in an outline hierarchy of primate groups into a set of nested boxes reflecting that same hierarchy. A cladogram can then be drawn illustrating how these groups are related in an evolutionary way.
Students are guided through a process by which three questions are addressed by retrieving beta hemoglobin sequences from online databases, and using online tools to compare those sequences in student-selected animals. The questions: (1) Are bats birds, or mammals?; (2) Are whales more closely related to artiodactyls, of perissodactyls?; and (3) should birds be included in the class Reptilia?
The module begins by introducing the three domains of life: bacteria, archaea and eukaryotes, and explains that all living things share a common ancestor. By understanding this single unifying concept, students are able to understand the evolutionary history and relationships of all living things. Students are introduced to the process of illustrating evolutionary relationships with branching diagrams called cladograms. Students learn that once a cladogram has been constructed for a group of organisms, it can be used to answer all kinds of interesting questions based on the shared inherited features of those organisms.
ADAPTATIONS, IMPERFECTIONS & CONTRIVANCES
Students are assigned to read and discuss selected and edited excerpts from the essays of Stephen Jay Gould on the subject of contrivances.
Each student is given a block of wood and a screw (or nail), and is asked to put the screw (or nail) into the block, without any tool (like a screwdriver or hammer). Their efforts, with varying success, leads to a discussion of "contrivances", using various items and strategies as make-do ("contrived") tools for which they were not intended, and an exploration of many examples of contrivances and other "imperfections" in the living world, especially in humans. This situation may be better explained by evolution rather than the result of "intelligent design".
Students are given a variety of materials and are asked to design A heat loss experiment that will result in a reasonable explanation of "Why don't whales have legs?"
VARIATION and NATURAL SELECTION
Students are introduced to the field of experimental evolution by evaluating skeletal changes in mice that have been artificially selected over many generations for the behavioral trait of voluntary exercise wheel running. A video presentation by Dr. Theodore Garland, Jr. of the University of California, Riverside discusses the experimental design and presents the results of the collaborative research on the structural, metabolic, and neural changes in the selected lines of mice. In an inquiry-based activity, students develop hypotheses about the skeletal changes that might occur in the legs of the selected mouse populations and design an investigation using measurements taken from photographed femurs (thigh bones) of mice from both selected lines and non-selected control lines.
A common criticism of natural selection is "how can it produce novel complex useful structures by pure random chance?" Darwin's answer to this "difficulty", (which he actually raised himself), was that selection is NOT a random process, and furthermore, it is cumulative, which he ably explained. Unfortunately, these facts are seldom included in typical classwork on evolution. It should be a required part for every presentation of natural selection.
This lesson provides an elegant, easy way for students to actually compare Darwin's cumulative non-random selection with the non-cumulative version so often erroneously implied. Students working in pairs attempt to produce a full sequence of 13 cards of one suit (ace - to king). This must be done by shuffling the suit of cards for each round, then checking the cards. Half the teams must look for the full sequence each time, and repeat the process until this is accomplished. The other teams start to "build" their sequence by pulling the ace when it first appears as the top card, then adding to the stack whenever the "next" card for the sequence is shuffled to the top. Discussion clearly reveals how the second method mimics Darwinian natural selection, while the first does not.
This activity provides an excellent introduction to the concept of biological complexity while at the same time demystifying and debunking Paley's argument that a complex "watch" is compelling evidence requiring a (complex) "watchmaker" (designer or creator). It employs an elegant, simple mathematical exercise to demonstrate this. It involves a randomizing component (a die), and a simple mathematical rule (the non-random component), resulting in the repeated plotting of points. Repeated cycles eventually produce an orderly pattern.
Students play the role of birds, go out on the school lawn, and pick up toothpick "stick worms" which have been previously been scattered on the lawn in equal numbers of green-stained and unstained. "Birds" are chased away before the "worm population" drops too low. The number of green and non-green "worms" are compared individually and for the whole class. Discussion relates the experience to the elements of natural selection.
A relatively simple scenario in which groups of students go hunting for beans in the lawn. Each group has a different tool (e.g. hand, spoon, fork, etc). There are three different colors of beans. The hunting goes for three rounds (generations), with extinctions and reproduction occurring between rounds.
Demonstrate how natural selection operates, using different colored paper chips to represent prey and a piece of fabric as a background (the environment). The predator (student) will hunt (select chips) to show that the best adapted, by color, are NOT chosen, and others which are poorly adapted (by standing out) ARE chosen. Thus, the best adapted survive and reproduce to pass on their traits. Survivors then "reproduce", and subsequent generations are preyed upon.
A very clever, creative multi-generational natural selection simulation, developed by Thomas Atkins (ENSI 92) and Gene Nelson of Fresno, California.
Video showing recent field work on a twenty two-year study of finch beaks on a small island in the Galapagos, showing natural selection clearly operating in the wild. Includes vignettes of Darwin's life, and the Grant family working and living on the island. Excellent video. Video-notes worksheet helps to guide viewing for students, and facilitates subsequent discussion.
Students participate in a contrived natural selection simulation in which they build and modify simple paper airplanes ("Origami Birds"). Created by Karin Westerling, ENSI 92. ALSO - see below.
Students participate in a contrived natural selection simulation in which they build and modify simple paper airplanes out of straws and paper ("Origami Birds") and generate four generations selecting for flight distance. To do this, students must make changes in the structures of the new "birds" of each generation. Those changes represent the results of random "mutations" in the DNA of each new bird, changes determined from the results of two random actions: spinning two random spinners. Each new bird is "flight-tested". The best-performing offspring (as defined by the teacher) then serves as the parent to the next generation, where the process is repeated. Modification based on research by Dr. T. Yamanoi, Tokyo University.
A Lesson in Lactose Intolerance, which offers evidence of natural selection in human populations, based geographic origins and customs. Developed by Therese Passerini (ENSI 90), presented at Reno NABT, Nov. 1998. (Not yet structured in ENSIweb format, but the lesson is now commercially available from Science Kit & Boreal Labs).
A short article which offers an excellent classroom strategy to help students resolve the all-to-common confusion of Lamarck's mechanism for evolution with Darwinian natural selection. By Richard Firenze.
Different subspecies of a California salamander are placed on grid map of California according to where samples were collected. Discussion focuses on patterns of their distribution, their likely evolutionary relationships, and probable sequence of formation from the original form (speciation). Very compelling experience of speciation and its role in evolution.
Using real data, students develop likely phylogenies for seven related populations of lizards living on the Canary Islands (off the West coast of Africa). Three phylogenetic charts will be constructed, each using different forms of data: geography, geology, morphology, and molecular genetics (DNA comparisons). Serves as an excellent example of MILE: Multiple Independent Line of Evidence, showing at least some degree of similarity of patterns and therefore mutual confirmation of the phylogeny.
Earth teems with a staggering variety of animals, including 9,000 kinds of birds, 28,000 types of fish, and more than 350,000 species of beetles. What explains this explosion of living creatures—1.4 million different species discovered so far, with perhaps another 50 million to go? The source of life's endless forms was a profound mystery until Charles Darwin brought forth his revolutionary idea of natural selection. But Darwin's radical insights raised as many questions as they answered. What actually drives evolution and turns one species into another? To what degree do different animals rely on the same genetic toolkit? What makes us uniquely human? And how did we evolve?
"What Darwin Never Knew" offers answers to riddles that Darwin couldn't explain. Breakthroughs in a brand-new science nicknamed "evo devo", are linking the enigmas of evolution to another of nature's great mysteries, the development of the embryo. NOVA takes viewers on a journey from the Galapagos Islands to the Arctic, and from the explosion of animal forms half a billion years ago to the research labs of today. Scientists are finally beginning to crack nature's biggest secrets at the genetic level. The results are confirming the brilliance of Darwin's insights while revealing clues to life's breathtaking diversity in ways the great naturalist could scarcely have imagined.
Fossil shells of a land snail are arranged by layers of age into a sequence pattern suggesting gradual change, or punctuated equilibria. Variation uses caminalcules in place of fossil shells.
Two sets of simulated fossils (caminalcules) are provided as cutouts. Students arrange them on two time scales. One set produces a visual example of "gradualism", the other shows "punctuated equilibria".
Students read and discuss articles presenting two alternative models about the extinction of dinosaurs. Criteria scientists use to get the "best" solution are encouraged ("Fair Test" strategy).
Students will experience the historical discovery of fossils which increasingly link whales to earlier land-dwelling mammals. This experience reveals how scientists can make predictions about past events, based on the theory that whales evolved. Such predictions suggest the age and location of sediments where fossils of early whales would most likely be found. This lesson also provides confirmation, with multiple independent lines of evidence, that there IS a series of intermediate forms, showing gradual accumulation of changes, linking certain terrestrial mammals with modern whales.
Students follow the Becoming Whales lesson with a look at more recent data (ankles and DNA) to see if their findings (and predictions based on those findings) are confirmed and sharpened. Students compare early whale ankle bones with similar ankle bones in other animals. They then compare sample strands of DNA found in suspected relatives to arrive at a conclusion about the closest living relative of whales today.
Students begin by seeking to answer a question: "Why have some freshwater populations of threespine stickleback fish lost their pelvic spines and body armor?" Data and analysis take them into some applied genetics and the Evo-Devo work on regulatory genes, where mutations only affect where and when a main gene is expressed, producing major changes in morphology (without fatal effects) on which natural selection can act. This exposes a likely pathway for evolutionary change to happen without the heavy risk that a mutation in a protein-producing gene might bring.
Students compare the DNA sequence data for a portion of the rat GULO gene (which helps make vitamin C) to the corresponding sequence in the inactive human GULO gene by translating the sequences and by aligning them. This lays ground work for exploring pseudogenes and the significance of these DNA sequences in recognizing shared common ancestry (Lesson B).
Students compare the DNA sequence data for a portion of the rat GULO gene to the corresponding sequence in the inactive GULO gene ("pseudogene") in humans, chimpanzees, orangutans, and crab-eating macaques by identifying the shared sequences in their alignment. They compare the pseudogene sequences and note a shared deletion. In addition, students do an alignment for the first 25 codons of the functional human beta globin gene and its pseduogene in humans, gorillas, and chimpanzees, then compare the pseudogenes and again note a shared deletion, as well as two other shared significant differences from the functional human sequence. Such shared deletions provide strong evidence for shared common ancestry (descent with modification), a natural process of macroevolution.
Students use Biology Workbench to explore DNA sequence data for the GULOP gene in humans, chimpanzees, orangutans, and crab-eating macaques and the beta globin gene and its pseduogene in humans, gorillas, and chimpanzees.
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