Banishing the Kingdoms November 23 2023, 0 Comments

What is your source for current information about life sciences? Do you share your discoveries of new information with your children? A curious adult who is still learning is a very important model for children.

What’s New in the Third Edition of Kingdoms of Life Connected? January 12 2023, 1 Comment

Last fall, I completed the third edition of my book, Kingdoms of Life Connected: A Teachers’ Guide to the Tree of Life. This came only six years after the second edition, which in turn came eight years after the first edition. “Why all this change?” you may ask.

I found that updates were needed because of changes in biologists’ view of the diversity of life. The data about how organisms are related continue to pour in, and because of this, the details of lineages and relationships change. You may be tempted to wait until the field stabilizes and stick with older ideas. Children, however, need a useful view of the diversity of life, even if it will be somewhat amended later. They cannot build on a foundation that is clearly obsolete. Specifically, it is no longer useful to present children with Five or Six Kingdoms, and those charts need to go in your history-of-science file.  

I updated Kingdoms of Life Connected from cover to cover. I redid the lists of learning resources – books and websites; I purged links that no longer worked and added new ones. Publishers and authors have brought forth valuable new books in recent years, and I added titles to the lists while retaining older but useful books. I revised all the text, including the activities and lesson suggestions. I fact-checked the information to make sure it was as up to date as I could make it.

There is one especially important addition, a new lesson for introducing to the Tree of Life chart to beginning elementary children. This lesson gives older children important concepts as well, particularly if they have not yet had this overview. The introductory lesson leads children to the idea that all life shared a common ancestor and is connected. It shows them the relationships between the major branches of life. For example, they learn that the animals and fungi are sister lineages and that plants are only distantly related to fungi.

I’ll give a brief summary of some of the changes below. For more information, see the book, which is available at (printed version). The ebook (pdf) is at

There are no big changes in the prokaryotes. I have kept a very basic approach because it takes extensive knowledge of biochemistry to understand the many branches of bacteria and archaea. Introductory college biology texts present a few basic lineages, and I felt that this approach would be good for children as well.  

In the protists, I rearranged the Excavata lineage on the Tree of Life chart. Now, the euglenazoa and kinetoplastids are sister lineages and the metamonads are the first branch. I expect that Excavata will be split apart and redone in the future. It probably won’t be a eukaryotic supergroup, but studies continue to confirm the other supergroups – Archaeplastida, SAR, and Amorphea.

Scientific terminology evolves, and I was happy to see a complicated name go away. The branch of the stramenopiles and alveolates was previously called Chromalveolata, but that term has fallen out of favor. It originally described a lineage that included two branches I didn’t show, the cryptophytes and haptophytes; these are now placed elsewhere on the Tree of Life. The branch of the stramenopiles and alveolates may get a new name, but it seems best to leave that branch blank for now.  

The fungi were the major branch that changed the most. The former Zygomycota lineage is now divided into two main lineages, the Mucoromycota and the Zoopagomycota. On my Tree of Life chart, I show the larger one, Murcoromycota. Its branches include the pin molds or Mucoromycotina (black bread mold, for example) and the arbuscular mycorrhiza fungi or Glomeromycotina (AM fungi). The AM fungi were previously placed on their own branch, but they have been added back to Mucoromycota. I didn’t add the Zoopagomycota to the Tree of Life chart, but if you have children who are interested in learning more, Fungarium by Katie Scott and Ester Gaya, is a good book for launching their explorations.

In the animal kingdom, studies have clarified some relationships in the protostome branch. You can give children the term “Spiralia” for the lineage previously called Lophotrochozoa. The whole branch is called Spiralia; “Lophotrochozoa” still refers to the mollusks and annelids. It is another of the situations where it is useful to know an older and newer term. “Lophotrochozoa” has been used for the Spiralia branch for about 20 years, and it appears in a number of websites. I recommend looking to the future and using “Spiralia” primarily. It is certainly easier to say and spell.

In the plant kingdom, studies have resolved several questions about the bryophytes. They are a single branch of life, a monophyletic lineage. The first branch was recently determined to be the hornworts. The mosses and liverworts are sister lineages. The older story was that the liverworts were the first branch because they do not have stomata. It appears that their ancestors lost their stomata rather than never having them.

The virus chapter now has suggestions for making a model of a coronavirus. I published this chapter as a stand-alone pdf in 2020. Note that if you have the third edition of Kingdoms of Life Connected, you already have the content of “What Is a Virus?”.

It is easy to become overwhelmed by all the names and branches of life. I recommend that you concentrate on the larger branches on the Tree of Life and continue to other branches as children (and you) learn about these and are interested in pursuing more. For in-depth studies at the elementary level, I recommend the digging further into the animal and plant kingdoms.

Start with the big overview of the Tree of Life. After that, my learning material, Sorting Branches on the Tree of Life: Vertebrates and Plants, is a good place to go. It is available as a pdf that you can print or as a printed material  

Enjoy your explorations of the Tree of Life!  

The Gorilla in the Montessori Room July 15 2022, 2 Comments

What is this about a gorilla in the Montessori room? Is it a radical new classroom pet?

The Gorilla in the Room

No, it is a symbol of an ongoing problem that is being ignored for many reasons – it is difficult, uncomfortable, and so big that it will take considerable effort to deal with it. Here is why I think there is a “gorilla” in Montessori classrooms.

Maria Montessori designed her brilliant elementary framework around five great lessons, and she constructed it with her perspective as an early 20th century European. Her understanding that children need spiritual nourishment, not just facts, guides us today. Her stories are tied into the science content she felt children should have. She gave them real knowledge, not a watered-down version, along with inspiration to learn more.

The inspiration and spiritual nourishment are still wonderful, but there is a problem with the content of those stories and the lessons that come from it. She used the state-of-the-art information for her time in the stories, and many classrooms still do that – they use the state-of-the-art biology from the mid-20th century. This leaves children woefully out of touch with today’s view of life science.

Biology has come a long way since the mid-20th century. Not only are two, five, or six kingdoms obsolete, but the whole idea of kingdoms is not what it once was. If you still use five or six kingdoms as your main lesson on the diversity of life, it is time to move those materials to the history of biology and move on. The Tree of Life provides the framework now, and the three kingdoms (fungus, animal, and plant) that are still valid are not the organizing framework for the diversity of life. Instead, they are major branches among many others on the Tree of Life. Biologists have extended classification to include the relationships between all kinds of life. Shared common ancestry drives classification, not just physical appearance.  

For an example, see the website for animals, The Shape of Life: The Story of the Animal Kingdom ( It has a tree of life that gives the derived traits for the lineages. You can download the pdf from and print it. This branching diagram is not for beginners, but it will help you see how the diversity of life is shown scientifically.


This website also has an artist’s Tree of Life for animals, and I think children would enjoy poring over it. It is by Ray Troll; the pdf is available at Even though it is an artist’s interpretation and shows little of the other branches of life, it has valid branches for animals.

Ray Troll's Tree of Life for animals


There has been such a revolution in biologists’ ideas about the diversity of life that it has required college professors to be flexible and ready to change. Some revise their course content on a yearly basis. DNA data has been a big part of the change, and biologists continue to acquire new data. The rapid change doesn’t mean that it is OK to stick with old ideas until the field settles down. It means that children need the new framework and new ideas about how biologists see life’s variety. They don’t need to spend time learning a system they will set aside in further studies.

Back to that “gorilla.” I see that inadequate movement toward new ideas is common in Montessori teacher education programs. The extent of change in biology means that everyone needs to learn current biology ideas, including teacher educators and teachers with all levels of experience. It calls for relevant conference presentations and professional development courses. It means that teachers can’t simply change a few terms and keep teaching the old framework.

Certainly, there has been progress in updating biology for Montessori schools. Cynthia Brunold-Conesa’s album, Life Science Lessons for Montessori Elementary Classrooms, has a totally new structure and current ideas. You can find it at

For more than two decades, I have been working to bring updated materials with current ideas to Montessorians. My recent video course, Life Science Literacy for Elementary Teachers, is available through Trillium Montessori at I have revised my books and card sets multiple times, and I continue to do so each time I reprint an item. The websites change, the classifications change, and even the terminology evolves.  

Montessori classrooms help children acquire knowledge. In biology, will it be useful knowledge, or will they have to relearn the subject later? It depends on whether Montessori leaders do something about that gorilla in the room. 

Priscilla Spears, July 2022 

Teaching accurate evolution concepts is important for people and the planet November 08 2021, 0 Comments

I have been studying the concepts of evolution and false ideas about this process. “Evolution” literally means “unrolling,” and we use the word as a name for the changes in life over time. I am convinced that children (and everyone else) need to know valid ideas about evolution as a basis for social justice and peace.

The idea that some life is more advanced or important than other life started with Aristotle and Plato. They used an animal-vegetable-mineral classification, which is an intuitive idea that still exists. It leads to misconceptions about how evolution occurs and what it produces.

Aristotle introduced the “scala naturae” or great chain of being, which is a ranking of organisms from “lower” to “higher.” He ranked animals with blood above those without – the invertebrates whose blood he didn’t recognize. Plants, of course, went beneath animals, followed by minerals. Soil was at the very bottom of the scheme, which is the opposite of our current view. Now we see soil as a unique combination of living and non-living, and the foundation and sustainer of life on land.

During the Middle Ages, the idea of a chain or ladder of life became a religious idea as well. At the top sat the deity with the angels beneath, then humans, and so on down the ladder. Religious authorities presented this ordering as divinely given, which likely helped keep those on the lower rungs of social structure down there doing the hard work.

At one time, biologists used the great chain of being concept, and scholars thought that all organisms were striving to improve and move up the ladder of life. When Darwin proposed his theory of evolution via natural selection, he included the idea that there was no direction to evolution. After genetics and molecular biology showed the mechanism of evolution, most biologists accepted the idea that evolution doesn’t have a goal. Some biologists still thought that life was evolving toward complexity or some pinnacle of evolution.

One of the most famous – and wrong – illustrations of evolution shows a monkey, an ape, a caveman, and a modern man marching along from left to right. Note that I said “man” not “human.” This iconic illustration always ends with a Caucasian male. It leaves the impression that white males are the ultimate product of evolution.

There is no pinnacle of evolution, only a many-branched Tree of Life. There are no “highly evolved” organisms vs. more primitive ones. All life in existence is very complex; it has thousands of molecules in a highly ordered arrangement, all functioning together. All extant life has been evolving for the same amount of time although some lineages have undergone more visible changes than others. If life continues to exist, it continues to evolve.

It may seem that evolution produces more complex life, but that is not always the case except for the earliest life. Think of life starting as simple cells. There wasn’t any room to get simpler, but the opportunities to become more complex were plentiful. Even with that, there are many instances of a lineage of life becoming less complex and losing structures rather than developing new ones. This has happened frequently with parasitic organisms, but free-living animals also give up structures. The echinoderm lineage is sister to the chordates, which means that they shared a common ancestor. One branch got more complex and developed vertebrae; the other got simpler and combined several organ systems into a water vascular system. Both are highly successful.

As far as anyone can tell, evolution has no special direction and no goal other than the survival of life, all kinds of life. Especially all kinds of life because it takes diversity for life to continue. There is no climbing to the top, whatever that might be. With no ladder of life, there are no missing links, and paleontologists no longer use that term.

What does this mean in the classroom? The guiding adult must take great care to express the concepts of evolution accurately and to remove any diagrams that give false impressions.

I’ve written previously about the problem of teleology, the idea that organisms change because they want to or need to do so, but it is worth repeating. Fish didn’t decide to try growing legs, and they didn’t get them because they wanted to get out of the water. Those are teleological ideas. If an organism could change because it wanted to do so, there would likely be a lot of three-armed people taking care of small children. 😊

I don’t mean to say that people can’t change; they certainly change their minds and may work to bring about other changes in their lives. Individuals do not evolve, however. Evolution can be defined as a change in the frequency of a trait in a population. The process of natural selection brings about this change. A random mutation can change a trait in an individual organism, but evolution doesn’t take place unless that trait is passed to offspring, AND it confers an advantage for surviving and reproducing.

In the classroom, if children see a Tree of Life diagram that shows humans (or mammals) as a part of the diversity of life, they will have a better perspective than if they see a row of equally spaced boxes with humans/mammals at the far right. If they see a timeline of humans that shows modern humans with a range of skin colors, it will give a more accurate impression of what the evidence indicates has happened. An accurate timeline of humans cannot be a straight line. See for a more realistic view.

A timeline of humans that ends in light-skinned and light-haired people is not fair to anyone. I think it is best if children understand that there are many colors and cultures of humans, and that all of them are equally evolved and equally valuable. You may ask best for what? Best for our species and the whole biosphere.

“Life is a copiously branching bush, continually pruned by the grim reaper of extinction, not a ladder of predictable progress.”

― Stephen Jay Gould, Wonderful Life: The Burgess Shale and the Nature of History

Priscilla Spears, November 2021

Why Montessorians need a new biology album July 28 2021, 0 Comments

Why does the Montessori world need a new biology album? Basically, there are two reasons...