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What goes on a chart of the animal kingdom? November 29 2018, 0 Comments

A chart of the animal kingdom is standard equipment for any Montessori elementary classroom. The chart could be purchased or made by the guiding adult. Either can be appropriate and useful to children. Conversely, either can have significant mistakes and misconceptions. Here are guidelines for choosing or making an animal kingdom chart.

First of all, the animal kingdom chart presents the major phyla. “What are those phyla?” you may ask. There are about 35 phyla of animals, and that is far too many to present to elementary children. Some have few members, and children are not likely to ever experience their members. The Wikipedia article on animals has a table that gives the number of species in the 11 largest phyla. Here is my list of phyla that show important structural features or notable evolutionary features. I consider the following “must haves” for the animal kingdom chart for beginning elementary.

Phylum Porifera, the sponges

Phylum Cnidaria, the anemones, jellyfish, corals, and hydras

Phylum Platyhelminthes, the flatworms

Phylum Annelida, the segmented worms – earthworms, leeches, and polychaete worms

Phylum Mollusca, the mollusks – snails, clams, octopuses, etc.

Phylum Nematoda, the nematodes or roundworms

Phylum Arthropoda, the arthropods – insects, crustaceans, spiders, and many others

Phylum Echinodermata, the echinoderms – starfish, sea urchins, sea cucumbers, etc.

Phylum Chordata, the chordates – lancelets, tunicates, and vertebrates (NOTE: Chordata is not equal to Vertebrata. The latter is a subphylum of Chordata.)

These belong on all animal kingdom charts to illustrate the range of creatures in this kingdom. There are other phyla of interest that can be added for a more advanced chart or one that spans elementary and secondary levels.

Phylum Ctenophora, the comb jellies – This phylum is significant because it is likely to be the second branch of the kingdom after the sponges. Ctenophores occur worldwide in marine waters. They were formerly grouped with the cnidarians in the obsolete phylum Coelenterata.

Phylum Rotifera, the rotifers – If children look at pond water under the microscope, it is likely that they will see these tiny animals. On a chart, rotifers would go near flatworms and segmented worms.

Phylum Ectoprocta or Bryozoa, the bryozoans or moss animals – Children are unlikely to observe these animals because they are about 0.5 mm across, but they may find bryozoan colonies at the beach. Use a guide to seashore life to identify them. Almost all bryozoans live in colonies, which can look like crusts on other organisms or rocks. Some form larger colonies that are commonly known as brown hairy tongues.

Phylum Brachiopoda, the brachiopods – These were much more common in the fossil record than they are now. The two halves of their shells enclose their top and bottom halves, whereas the two halves of a clam shell enclose the left and right sides of the mollusk’s body. This makes brachiopods a bit challenging for the beginner. I would hold this phylum for later introduction, perhaps along with studies of the Paleozoic Era.

Phylum Hemichordata – This small phylum of marine creatures includes acorn worms and pleurobranchs, which are tiny colonial animals. The extinct graptolites are placed in this phylum. Despite its name, this phylum is more closely related to echinoderms than to chordates. It is too confusing for beginners. Let children get a firm grasp of chordates before you introduce this phylum.

Other minor phyla – There is plenty for beginners to learn without adding minor phyla, however it is good to be prepared in case your children encounter an animal of a minor phylum. Many of these will be marine animals, and so a guide to marine life can be useful to place these finds into a phylum. Possibilities include ribbons worms, horsehair worms, velvet worms, and tardigrades.

Keep in mind why we are introducing children to various animal phyla. In this kingdom, each phylum has a different body plan. Children learn about the unique characteristics of each lineage. To this end, the illustrations on the chart should show at least one example that illustrates the identifying traits. Close up photos of a portion of the animal’s body or photos with a messy background or many animals together are not helpful for seeing the body plan of the organism.

Of course, the description of the phylum needs to include its scientific name. Don’t stop there, however. Children may not be able to find further information that they can read and understand unless they have common names as well. They likely know many of the common names, and it boosts learning to start with something known and move to new information.

The phylum description needs to state simply and straightforwardly the main features of that lineage. For example, segmented worms should be described as having repeated segments in their bodies. If you have a good illustration, it is easier to describe important visible features.  

Finally, how do you arrange the phyla on the animal kingdom chart? HINT: It isn’t in an evenly-spaced straight line. Some phyla are more closely related than others. The animal kingdom chart that high school or college students will see is a phylogeny, a branching diagram. If you do not wish to start with a phylogeny, you can still group related phyla together. The echinoderms and the chordates are sister phyla. So are the nematodes and the arthropods. The mollusks and annelids are another closely related pair. The animal kingdom chart from InPrint for Children is a good example of grouping phyla.

For any studies of classification beneath the level of phyla, it is best to use a phylogeny. For an example, see my material, “From the Chordates to Mammals: Exploring the Tree of Life.” https://big-picture-science.myshopify.com/collections/biology/products/from-chordates-to-mammals-exploring-the-tree-of-life

Happy animal explorations! For more information about the animal phyla and the phylogeny of the animal kingdom, see my book, Kingdoms of Life Connected.  


The Tree of Life versus the Timeline of Life March 29 2017, 0 Comments

Someone has posted my Tree of Life chart on Pinterest and suggested in the caption that it could be a substitute for the Timeline of Life. NOT SO! These are two different materials with two different uses.

The Tree of Life does not show details of life through time. It shows extant animals and their lineages. People may be confused because classification has an element of time now. We group organisms by their common ancestors. You can’t show relatives without some reference to time. My cousins and I share a set of grandparents, so we have a recent common ancestor. That’s what makes us closely related.

Classification has become systematics (more on that in a later post). Biologists do not show rows of evenly spaced boxes with no connections when they diagram a kingdom or other related life. Instead, they connect the boxes (or names) with a branching diagram to show which organisms share more recent common ancestors.

The Tree of Life chart is used much like a Five Kingdoms chart was. If you are still using a Five Kingdoms, Six Kingdoms, or heaven forbid, a Two Kingdoms chart, you need to change to a different kind of chart. A Tree of Life chart is used to introduce children to the diversity of life. When I give this lesson, I tell children that this chart has a branch for all the major kinds of life on Earth. (And you may have one precocious child who asks “What about viruses?” No, they don’t belong on the organisms’ Tree of Life. They have their own.)

I can envision directing children’s attention to the big, black branches and noting that they are all connected, and they all share a common origin. I would also say that there are many, many varieties of life, and we would have a hard time studying it all at once. Instead, we put certain branches together for the purpose of focusing on them. Three of these major branches are called kingdoms because they are all the descendants of a common ancestor. They are outlined with color rectangles – yellow for fungi, red for animals, and green for land plants. The other two rectangles show organisms that we put together for the purposes of study – purple for prokaryotes and blue for protists.

The Tree of Life is used for children ages 6-9 to show them the big overview of life. They enjoy putting the cards on the solid, colored rectangles. The text on the back of the illustrations helps children place the picture of the organism. To help them find the right place, the major section and the name of the branch are in bold typeface. Older children and even secondary level students can still use the Tree of Life, and they should have an opportunity to place the cards and discuss this chart. Do they see that animals and fungi are sister kingdoms? This is why treating fungal infections is so hard.

On the other hand, the Timeline of Life shows the organisms that have lived during the time periods of the Phanerozoic Eon. A few timelines may have a bit of the previous Late Proterozoic, but the major emphasis is on life since the beginning of the Cambrian Period. There is nothing other than a timeline of life that can show this. Unfortunately the traditional Montessori Timeline of Life is riddled with mistakes – omission of the five major extinctions, all extinctions shown as ice ages, indistinct organisms, no grouping of related organisms, and my worst pet peeve, converging red lines that seem to show several lineages being fused into one.

OK, enough attacks on the Timeline of Life. It is still an important material for children, and I think it is important to use one that is updated and corrected, either by the teacher or by a company that has carefully researched its product. The Timeline of Life helps children understand how life has changed through time. (One last rant – add the Devonian explosion of plants! During that period, the land turned green as plants changed from a low green fuzz to trees that bore seeds. The Devonian – It’s not just for fishes!)

As a reminder of what is available on my website to aid you, my Outline of Geologic Time and the History of Life has lots of information that will help you make an accurate, up-to-date Timeline of Life. The Tree of Life chart is still a free download – my gift to the Montessori community. My book, Kingdoms of Life Connected, is a teacher’s guide to the tree of life. I updated it in the fall of 2016.

May you and your children enjoy exploring the living world, both its diversity and its history.


Plant surprises in the desert February 17 2017, 0 Comments

In January, I visited Tucson, Arizona and enjoyed exploring the Sonoran Desert. The plants there show many adaptations to the heat and dryness. The cacti and palo verde trees are what I expected. What surprised me is that plants I thought would need much more moisture are also able to survive in that climate.

There had been rain before my visit, enough that several hiking trails were impassable because normally dry creeks were flowing. As usual, if you want life, just add water. The plants that need moisture to reproduce, the spore-bearing plants, came out of hiding and were thriving. I saw a number of different ferns, but those weren’t a big surprise. I had seen ferns growing from cracks in lava flows before. The key for ferns seems to be finding a moisture-conserving crack on the shady side of a rock outcrop.

The spike mosses, genus Selaginella, were fluffed out and green. One of their common names is resurrection plant, so you can image how they look when they are dry. Spike mosses are not true mosses. They are members of the club moss lineage aka the lycophytes. One Sonoran species, Selaginella rupicola, is called rock-loving spike moss.  There were hillsides with many spike mosses protruding from cracks between rocks.

The mosses were looking very green and active. They are known for their ability to dry out and wait for water. They formed their green carpets out on more open ground and in sheltered rock overhangs. It was in one of the latter habitats that I found the big surprise. There were liverworts growing with the mosses.

Liverworts are the plants that have leaf pores that are always open. I think of liverworts as growing in habitats that have abundant moisture, not just isolated periods of wet weather. It is true that the liverworts in Oregon’s Willamette Valley survive the summer drought, but the humidity is never as low nor the temperatures as high as in the Sonoran Desert. The Sonoran liverworts are small, thalloid ones, much smaller than the ones native to western Oregon. They have the right appearance for a liverwort. They look like a flat leaf growing right on the ground, and they branch into two equal parts, which gives them a “Y” shape. They must have special adaptations and be very tough and resilient to live the desert.

Plants offer surprises in all habitats, not just the desert. You just have to take the time to look.


The New Edition of Kingdoms of Life Connected is here! October 30 2016, 0 Comments



The second edition of my book, Kingdoms of Life Connected: A Teacher’s Guide to the Tree of Life, is available now. I wrote the first edition in 2008, and it was already time for an update this year. New information keeps coming in all fields of science. This leads to gradually evolving ideas, but change has been exceptionally rapid in the field of systematics, the study of the diversity of life.

The flood of DNA information continues, and we must bear that in mind in our presentations. It would be better to state that the story you tell is based on the evidence scientists have gathered for now. In the future, there could be adjustments. This doesn’t mean that all the information about the Tree of Life will change. Instead there will be small alterations. The potential for change certainly doesn’t excuse the presentation of obsolete classifications as anything other than history.  

One of the hardest tasks for my book revision was finding up-to-date children’s books about the diversity of life. I had to leave many older, but valuable, books on the resource lists. At least it is easier to find out-of-print books now than it was a decade ago. I also found that publishers have reprinted some valuable older books. They include Peter Loewer’s Pond Water Zoo: An Introduction to Microscopic Life. Jean Jenkins illustrated this book in black and white, and it has attractive, clear drawings of many protists, bacteria, and microscopic animals, along with text that upper elementary children can read. You will have to warn your children that the classification scheme presented, the Five Kingdoms, is obsolete, but the information about the groups of organisms is still quite good.

A forty-year-old book by Alvin and Virginia Silverstein, Metamorphosis: Nature’s Magical Transformations, has been reprinted by Dover Books. It has a chapter on sea squirts that shows the tadpole-like larval stage and tells about the life cycle of these chordates. I haven’t found another children’s book that tells this story. The black and white illustrations show how old the book is, but there didn’t seem to be a good alternative.

I know the pain of having to purchase a new edition of a reference book. My favorite biology textbook cost nearly $200, and I see the new edition, just published this month, is priced at $244. Yikes, that’s hard on the budget. If you own the first edition of Kingdoms of Life Connected, you will be able to purchase the ebook version – the pdf file – of the book at a reduced price. Please email info (at) bigpicturescience (dot) biz for information about how to do this.


Three cheers (and three books) for bacteria! September 10 2016, 0 Comments

I’m always happy to find children’s books that portray bacteria as something other than germs. In my recent searches, I’ve found three gems. Two of them came from Australia, but I found the shipping was quick. The publisher is Free Scale Network, and the books are sold by Small Friends Books http://www.smallfriendsbooks.com/. The authors are Ailsa Wild, Aviva Reed, Briony Barr, and Dr. Gregory Crocetti.

It’s not often that bacteria get to be the protagonists, but in The Squid, the Vibrio, and the Moon the heroes are bacteria that help a young bobtail squid evade its predators. The story is set near the Hawaiian Islands, and it is dramatic and engaging. The attractive illustrations do a great job of supporting the story. They combine scales and will need some explanation, but the size scale at the front will help children keep all the components of the story in perspective.

The second book, Zobi and the Zoox, is set in a coral colony on the Great Barrier Reef. The protagonist is a rhizobia bacterium, Zobi for short. The action takes place in a coral polyp named Darian. The personification of these organisms could be distracting, but it isn’t. It helps one keep the characters separate and follow the action. There’s plenty of action as the coral faces warming in the ocean.

 

Both of these books can give children a greater appreciation for the many roles that bacteria play in making the biosphere work. It is easy to say that bacteria are an important part of all ecosystems, but that statement needs to be followed with great examples of actual symbioses like these books provide.

These two books are 38 pages long, and they can be enjoyed as a read-aloud by beginning elementary children. Older elementary can read the books themselves, and even secondary levels can learn from them. There is a glossary and several pages of additional information in the back of the books.

The third book that would be a great addition for studies of the microbial world is Inside Your Insides: A Guide to the Microbes That Call You Home by Claire Eamer, illustrated by Marie-Eve Tremblay. It was just released this month. This book has a wide range of information about microbes – what they are, where they live, and what they have to do with us and our world. The illustrations are goofy and cartoonish, but they work well enough to help children picture what is going on. The information is accurate and current, something that is hard to find in any children’s science book, much less one on microbes. Upper elementary children will likely enjoy the corny jokes sprinkled through the book, but they will also find plenty of good information. You could read it to lower elementary children.


Tweaking the Tree of Life - Again! August 19 2016, 0 Comments

If you look closely at my Tree of Life chart, you may notice changes. Knowledge about the early branches of the eukaryotes has grown, and it was time for another adjustment in the protists. This time I changed the label on the unikonts to also include a newer term for them, the Amorphea. Some biologists wanted this change because the original hypothesis about what makes the unikonts unique failed. The unikonts do not always have one flagellum, and they have two basal bodies (the part from which flagella grow), like other eukaryotes. What they do have is a unique fusion of three genes. This condition is so rare that it is unlikely to arise twice. The lineage of amoebas, animals, and fungi is still called the unikonts by many biologists, so I left that name on the chart.

The other main branch of eukaryotes, known informally as the bikonts, has a fusion of two different genes, another rare feature. The branch that includes chromalveolates (brown algae, diatoms, ciliates, etc.) and rhizarians (foraminiferans, radiolarians, etc.) has a much less wieldy name. It is now known as SAR (or Sar), an abbreviation for stramenopiles, alveolates, and rhizarians, and I added this to the chart. The evidence now points to some associations that I wanted to include on my Tree of Life. It appears that the Archaeplastida and SAR are more closely related to each other than they are to the Excavata (euglenas, Giardia, etc.). I’ve moved the branch positions on the chart to show this.

I like a newer term for the main branches of the eukaryotes. They are called the eukaryotic supergroups, which is a good descriptor for them.

You may be wondering what to do with your Tree of Life chart if you printed it from the older files. At lower elementary, I would do little more than adding the SAR and Amorphea labels. At that level, it is about showing a broad sweep of life, not the more exacting details. At upper elementary, you may wish to briefly explain about the changes since your chart was printed. Secondary students can learn more about these changes and modify their chart if they are interested.

And then there is that little fact we like to ignore. There are at least as many organisms not shown on our charts (even the more sophisticated scientific ones) as we show there. DNA studies show as many or more bacteria that have never been cultured or named as known bacteria. There are many named, but unplaced protists. Life isn’t simple! Is this the last version of the Tree of Life? Not likely, but it works for now.

You may also be wondering why I bothered to change the chart. Why not start new users of it with the most up-to-date information? As the flood of information continues, it will be best to go forward, not back. The most important thing is that children understand the Tree of Life and the evolutionary history it reflects. As a recent article in Nature Microbiology (2016, article number 16048) states “The tree of life is one of the most important organizing principles in biology.”


New ways to look at the Tree of Life November 21 2015, 1 Comment

I have two new posters that do a good job showing the history and diversity of life. The first is just out from Fairhope Graphics, and it is called “A History of Existing Angiosperms.” The many branches of flowering plants show up very well on this poster. You can see why there’s more to flowering plant lineages than monocots and dicots. The timescale on the left of this poster could lead to confusion, so you will need to explain to your children that all the pictures show flowering plants that still exist. Each illustration is placed at the time when we think its lineage originated. 

An important qualifier for this information – plant fossils are so much harder to find than large vertebrate fossils. Paleobotanists have to piece the story together from small, hard-to-preserve fragments, not large bones, so it could well be that a number of these plants will have a different age of origin as scientists obtain more fossil data. That should not detract from the information show here, however.

You can see from this poster that the plants had developed their major lineages before the K-Pg (K-T) extinction, and these lineages survived much better than the large vertebrates. The poster has the number of species and the common names of a few members for each lineage.

Look for the three main branches of angiosperms, the magnoliids, the monocots, and the eudicots, on the poster. You can also find two large branches of the eudicots, the rosids and the asterids. The rosids split into the fabids and the malvids. The asterid subdivisions are the lamiids and campanulids. These seem like a bunch of big meaningless names until you put a flower image with them, so this Fairhope Graphics poster will help make the lineages more memorable.

Fairhope Graphics also has useful posters on the lineages of birds, the Tree of Life at a simple and more advanced level, and the history of the Earth.

My second recently acquired poster is from a company called Evogeneao, which they explain on their website is short for evolutionary genealogy. The motto of this organization is “Life on Earth is one big extended family.”  Their “Evolution Cousin” poster shows their branching diagram for all of life, along with several familiar organisms and a number that reflects their relationship to us. For instance, your cat is your 27 millionth cousin. You can also get a larger poster that features the Tree of Life as the main graphic and gives information about it. These posters would be great for an impressionistic lesson on the Tree of Life. If you decide to use one of these posters in your classroom (or even if you do not) you will find it useful to read the Tree of Life page under the “Learn” menu on the Evogeneao website.

Under the “Explore” menu there, you can select “Tree of Life Explorer.” When you can click on an organism, you will see lines appear from humans and the selected organism. These lines meet at the most recent common ancestor. It is a very cool illustration of our relation to all of life.


The Big Picture for Botany, Part 2 June 15 2015, 0 Comments

I’m continuing on my commentary about my botany materials and how to choose them, this time with emphasis on the older elementary child.

Children in the 9-12 year-old range have different needs than the younger elementary ones, so they are not likely to find the little booklets and three-part cards of Illustrated Botany for Children attractive. They can, however, use the wall charts (summary charts) from that material to review or to check on terminology. The file for printing the wall charts by themselves is available. See http://big-picture-science.myshopify.com/collections/montessori-botany-materials/products/illustrated-botany-for-children-wall-charts-only

If you have my book, Plant Lessons: Introducing Children to Plant Form and Function, you have a number of lesson avenues to further botany studies. If your children have had the basics, then you can go deeper into flower structure, plant adaptations, fruits, and seed structure and function.

My botany photo cards set 1, Major Branches of the Plant Kingdom, is a good way to launch studies of the diversity of plants. While I would hope that you can have many of the branches of the plant kingdom represented in classroom houseplants, you are not likely to have many reproductive structures or the rarer plants available. The photos allow children to see structures and plants that you can’t otherwise provide.

If you are basing your botany studies on flowering plant families (an excellent way to structure botany), then you have lots of interesting botany yet to cover. Even if children studied a flowering plant family each month in their three earlier years of elementary, that is only 27 families out of over a hundred that might be found in temperate North America, either as natives or imported ornamentals or as food plants. The total count of angiosperm families is 413 in the last official publication. The number of families that you may experience will depend on the continent on which you reside, and on your local climate and growing conditions. The tropics have a much greater diversity than temperate areas. If children have not studied flowering plant families before, they can dig into them at upper elementary level.

Photo card set 2, Flowering Plant Families, is an introduction to 14 flowering plant families. The photos each have text on the back to start children’s research about these lineages. The families are a sampling across the major lineages of angiosperms. The efile of my PowerPoint presentation on flowering plant families, designed first for adult botany education, is available as a download. This pdf shows 20 families, eleven of which are not in photo card set 2. The PowerPoint slides are illustrated with color photos, and the pdf is at sufficient resolution for printing. Purchasers have the right to print the slides, but only for their own classroom. The slides can serve as research starters, although the photo cards have more information, and the text is in complete sentences vs. the phrases on the slides.

Photo card set 3, 48 Flowers for Study and Sorting, can be used with many levels of students. This set has examples of a wide variety of flower features, and includes a table to help teachers pick the right cards for a variety of lessons, from simple naming of flowers to details of their structure. While younger children will likely be sorting the pictures, upper elementary and secondary students can use the accompanying text cards to learn more about the structural details and the lineages of the plants. For example, the photo that symbolizes this set is a flower of blue flax. It is a eudicot flower with distinct petals that shows radial symmetry. The text card tells that this plant is a member of the rosid lineage of eudicots, and of the fabid lineage of rosids. Its order and family are also given.

How about structuring your botany around food plants? You could combine history of the plant’s domestication, botany of its flowers, and even include to culinary uses. The practical application of farming at middle school level is another layer of this study. Knowledge of flowering plant families can help with the planning of crop rotation and fertilizer applications.

Dig in! Enjoy the unfolding miracles of the plant kingdom that go on all around you.


Octopuses and other animals April 14 2015, 0 Comments

There’s a great new book out called Octopuses! Strange and Wonderful. It is by Laurence Pringle and is illustrated by Meryl Henderson. Together they present an attractive, accurate, and informative book about octopuses and other mollusks as well. The book would be an engaging read-aloud for younger elementary children and a good research material for upper elementary. I liked the information about how mollusks’ bodies are structured and how they work. Obviously this author researches his subjects carefully, and he knows how to tell a good story as well.

When I looked on Laurence Pringle’s website, I discovered that he has produced many highly rated children’s science books. The Strange and Wonderful series includes books on scorpions, cicadas, alligators and crocodiles, snakes, bats, and sharks. I was familiar with another high quality book by this author, A Dragon in the Sky: The Story of a Green Darner Dragonfly, published in 2001. I’m not sure how I missed the Strange and Wonderful series, but I will certainly seek it out now.

Another volume I have acquired lately is Animal Earth: The Amazing Diversity of Living Creatures by Ross Piper. It has many uses, from providing gorgeous illustrations of all sorts of animals to giving detailed biology for secondary student research. When I say all sorts of animals, I mean that the book covers all of the 34 phyla currently recognized in the animal kingdom. There is a chapter on animal lineages that helps one understand the current arrangement of those phyla on evolutionary trees (cladograms). The book is structured to follow the cladogram in the contents page. After the first branches of animals, the section on bilaterial animals starts with deuterostomes, and so the chordates, including us, are near the front of the book. Then it covers the protostomes, starting with the molting animals, including arthropods and nematodes. The clade called lophotrochozoa comes next, with annelids, mollusks, flatworms, and rotifers. The order alone will stimulate thought.

I found What on Earth?: 100 of Our Planet’s Most Amazing New Species while I was browsing in a bookstore. I highly recommend spending some time going through the stacks at bookstores, particularly those with a science section. I find things there that I missed on Amazon. This little book by Quentin Wheeler and Sara Pennak will likely stimulate conversations and research about a wide range of life. The 100 species are primarily animals, but fungi, plants, and a few protists also appear. There are even two bacteria. A feast for curiosity indeed.