May/June 2017 – Vol. 29 No. 7

The Tree Room: A New Online Resource for Teaching Evolutionary Relationships

Posted: Thursday, November 12th, 2015

by Anna Thanukos, Teresa MacDonald, David Heiser, and Robert Ross

Understanding evolutionary trees is important for students because trees visually represent the idea that all life is genealogically linked. This powerful idea, tied to Next Generation Science Standards MS-LS4-2 and HS-LS4-1, is one of those most fundamental concepts that biological evolution offers to explain the biological world. The implication is that any set of species, no matter how distantly related, share common ancestors at some point in evolutionary history. Evolutionary trees are an efficient way to communicate that idea. It turns out, however, that evolutionary trees are not quite as straightforward to interpret as they may at first appear — so where can a teacher turn for a user-friendly introduction to their use in the classroom?

The Tree Room is a new component of UC Berkeley’s renowned Understanding Evolution website. It contains resources both for teachers in K-16 education and for exhibition designers at informal science education venues such as museums, nature centers, zoos, and aquariums. The Tree Room provides user-friendly, accessible information on how to interpret trees, how they are built, and how they are relevant to society. The website starts with a Primer on trees that can help one learn the basics of evolutionary trees.

Lisa White (Assistant Director for Education and Public Programs at the University of California Museum of Paleontology) teaches about reading evolutionary trees.

Lisa White (Assistant Director for Education and Public Programs at the University of California Museum of Paleontology) teaches about reading evolutionary trees.

The origins of the new website emerged from research within the past decade that documents how evolutionary trees are often misunderstood by the public, including our students. For example, commonly students pay most attention to the ordering of taxa along the tips of a tree, without looking carefully at the branching pattern. Students might assume, therefore, that taxa next to each other are necessarily the most closely related. Students might also assume that one side of a tree, often the right side on a tree positioned “upward,” includes taxa that are more “advanced.” Branching patterns of evolutionary trees, however, can be shown in any order and communicate relative recency of splitting of lineages; in fact, branches can be flipped (rotated) and still communicate the same information. The section of the website “Tree misinterpretations” provides many more examples.

The tree on the left may be misinterpreted as showing evolutionary “progress” toward the top of the tree.

The tree on the left may be misinterpreted as showing evolutionary “progress” toward the top of the tree.

A wide variety of evolutionary tree forms are encountered through textbooks, popular media, and elsewhere, increasing the challenge of interpreting them. These designs range from sets of branching lines to graphics that look like actual trees or branching blobs. The Tree Room’s Field Guide explains how to interpret these various tree forms and their features, and ways in which some designs are more accessible than others. Research has shown, for example, that trees with squared corners (picture a tuning fork) are easier to interpret than the diagonal and circular trees that are common in scientific literature. Blobby trees look friendly but tend to be inherently ambiguous, because it’s unclear how exactly the lineages are related to each other.

The “squarish-corner” form of branching tree is easiest to interpret for students among the common forms of evolutionary tree graphics.

The “squarish-corner” form of branching tree is easiest to interpret for students among the common forms of evolutionary tree graphics.

The Field Guide to Trees home screen shows eight categories of evolutionary tree graphics, The “blobby” (lower left) and “tree-like” (left of the circular tree) designs are considered problematic particularly because of the difficulty in identifying branching points. 

The Field Guide to Trees home screen shows eight categories of evolutionary tree graphics, The “blobby” (lower left) and “tree-like” (left of the circular tree) designs are considered problematic particularly because of the difficulty in identifying branching points.

In the “For teachers” part of the site are ideas for incorporating tree-thinking exercises into curricula and a searchable database of dozens of vetted lessons and tools for teaching about trees. These lessons and resources, for grades 6 to 16, can be searched by grade level, keyword, and type (for example, lab activity, article, tutorial, and so on). Under the link “For museums and zoos” are resources written with museum exhibition designers in mind. However, some of these resources, in particular the section called Tips for tree design, may be useful for teachers who want to create new evolutionary tree graphics or modify existing ones for their teaching.

What did T. rex taste like? This web based module explores common ancestry and evolutionary relationships and is one example of lessons that can be found in the searchable database.

What did T. rex taste like? This web based module explores common ancestry and evolutionary relationships and is one example of lessons that can be found in the searchable database.

There’s another reason for students to understand evolutionary trees beyond the fundamental idea of common ancestry. Evolutionary trees are increasingly used to inform new biological research relevant to students’ lives, such as determining the origin and spread of infectious diseases, making crop choices in changing environments, choosing taxa to investigate for new medicines, and understanding the spread of invasive species. Our students may or may not be doing this research for their careers, but it will surely influence their lives and communities.

The Tree Room website was officially launched in May 2015. It was developed through a partnership among the University of California Museum of Paleontology, the University of Kansas Natural History Museum, the Yale Peabody Museum, and the Paleontological Research Institution, with input from a wide variety of evolutionary biologists and science educators. The project was supported with funds from the Institute of Museum and Library Services (grant number LG-26-12-0578-12).

Anna Thanukos develops and writes science education content for the University of California Museum of Paleontology in Berkeley (thanukos@berkeley.edu). Teresa MacDonald runs the education program at the University of Kansas Natural History Museum in Lawrence, Kansas (tmacd@ku.edu), David Heiser runs the education program at the Peabody Museum of Natural History at Yale University in New Haven, CT (david.heiser@yale.edu), and Rob Ross runs the education program at the Paleontological Research Institution in Ithaca, NY (rmr16@cornell.edu).

All images are from the Understanding Evolution website and are used by permission of the University of California at Berkeley.

Written by Guest Contributor

From time to time CSTA receives contributions from guest contributors. The opinions and views expressed by these contributors are not necessarily those of CSTA. By publishing these articles CSTA does not make any endorsements or statements of support of the author or their contribution, either explicit or implicit. All links to outside sources are subject to CSTA’s Disclaimer Policy: http://www.classroomscience.org/disclaimer.

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CSTA Annual Conference Early Bird Rates End July 14

Posted: Wednesday, July 12th, 2017

by Jessica Sawko

Teachers engaged in workshop activity

Teachers engaging in hands-on learning during a workshop at the 2016 CSTA conference.

Don’t miss your chance to register at the early bird rate for the 2017 CSTA Conference – the early-bird rate closes July 14. Need ideas on how to secure funding for your participation? Visit our website for suggestions, a budget planning tool, and downloadable justification letter to share with your admin. Want to take advantage of the early rate – but know your district will pay eventually? Register online today and CSTA will reimburse you when we receive payment from your district/employer. (For more information on how that works contact Zi Stair in the office for details – 916-979-7004 or zi@cascience.org.)

New Information Now Available On-line:

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Goodbye Outgoing and Welcome Incoming CSTA Board Members

Posted: Wednesday, July 12th, 2017

Jill Grace

Jill Grace, CSTA President, 2017-2019

On July 1, 2017 five CSTA members concluded their service and four new board members joined the ranks of the CSTA Board of Directors. CSTA is so grateful for all the volunteer board of directors who contribute hours upon hours of time and energy to advance the work of the association. At the June 3 board meeting, CSTA was able to say goodbye to the outgoing board members and welcome the incoming members.

This new year also brings with it a new president for CSTA. As of July 1, 2017 Jill Grace is the president of the California Science Teachers Association. Jill is a graduate of California State University, Long Beach, a former middle school science teacher, and is currently a Regional Director with the K-12 Alliance @ WestEd where she works with California NGSS K-8 Early Implementation Initiative districts and charter networks in the San Diego area.

Outgoing Board Members

  • Laura Henriques (President-Elect: 2011 – 2013, President: 2013 – 2015, Past President: 2015 – 2017)
  • Valerie Joyner (Region 1 Director: 2009 – 2013, Primary Director: 2013 – 2017)
  • Mary Whaley (Informal Science Education Director: 2013 – 2017)
  • Sue Campbell (Middle School/Jr. High Director: 2015 – 2017)
  • Marcus Tessier (2-Year College Director: 2015 – 2017)

Learn More…

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Finding My Student’s Motivation of Learning Through Engineering Tasks

Posted: Wednesday, July 12th, 2017

by Huda Ali Gubary and Susheela Nath

It’s 8:02 and the bell rings. My students’ walk in and pick up an entry ticket based on yesterday’s lesson and homework. My countdown starts for students to begin…3, 2, 1. Ten students are on task and diligently completing the work, twenty are off task with behaviors ranging from talking up a storm with their neighbors to silently staring off into space. This was the start of my classes, more often than not. My students rarely showed the enthusiasm for a class that I had eagerly prepared for. I spent so much time searching for ways to get my students excited about the concepts they were learning. I wanted them to feel a connection to the lessons and come into my class motivated about what they were going to learn next. I would ask myself how I could make my class memorable where the kids were in the driver’s seat of learning. Incorporating engineering made this possible. Learn More…

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Written by NGSS Early Implementer

NGSS Early Implementer

In 2015 CSTA began to publish a series of articles written by teachers participating in the California NGSS k-8 Early Implementation Initiative. This article was written by an educator(s) participating in the initiative. CSTA thanks them for their contributions and for sharing their experience with the science teaching community.

State Schools Chief Tom Torlakson Unveils Updated Recommended Literature List

Posted: Wednesday, July 12th, 2017

SACRAMENTO—State Superintendent of Public Instruction Tom Torlakson unveiled an addition of 285 award-winning titles to the Recommended Literature: Prekindergarten Through Grade Twelve list.

“The books our students read help broaden their perspectives, enhance their knowledge, and fire their imaginations,” Torlakson said. “The addition of these award-winning titles represents the state’s continued commitment to the interests and engagement of California’s young readers.”

The Recommended Literature: Prekindergarten Through Grade Twelve list is a collection of more than 8,000 titles of recommended reading for children and adolescents. Reflecting contemporary and classic titles, including California authors, this online list provides an exciting range of literature that students should be reading at school and for pleasure. Works include fiction, nonfiction, poetry, and drama to provide for a variety of tastes, interests, and abilities. Learn More…

Written by Guest Contributor

From time to time CSTA receives contributions from guest contributors. The opinions and views expressed by these contributors are not necessarily those of CSTA. By publishing these articles CSTA does not make any endorsements or statements of support of the author or their contribution, either explicit or implicit. All links to outside sources are subject to CSTA’s Disclaimer Policy: http://www.classroomscience.org/disclaimer.

Teaching Science in the Time of Alternative Facts – Why NGSS Can Help (somewhat)

Posted: Wednesday, July 12th, 2017

by Peter A’Hearn

The father of one of my students gave me a book: In the Beginning: Compelling Evidence for Creation and the Flood by Walt Brown, Ph. D. He had heard that I was teaching Plate Tectonics and wanted me to consider another perspective. The book offered the idea that the evidence for plate tectonics could be better understood if we considered the idea that beneath the continent of Pangaea was a huge underground layer of water that suddenly burst forth from a rift between the now continents of Africa and South America. The waters shot up and the continents hydroplaned apart on the water layer to their current positions. The force of the movement pushed up great mountain ranges which are still settling to this day, resulting in earthquakes along the margins of continents. This had happened about 6,000 years ago and created a great worldwide flood. Learn More…

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Written by Peter AHearn

Peter AHearn

Peter A’Hearn is the Region 4 Director for CSTA.