Scientists announced a new tree of life on April 11. Representing the kinship of all organisms, the biological tree of life illustrates abundance and diversity of life beyond anything previously known. More than 1000 newly-sequenced organisms appear on the revised tree, including bacteria from a hot spring in Yellowstone National Park and bacteria from the inside of a dolphin's mouth.
"Wonderful Life" is how biologist Stephen Jay Gould describes this amazing diversity and kinship. I saw it first-hand on a hike to the world's most important fossil bed, the Burgess Shale Formation, high in the Canadian Rockies, during The Enhancing Life Project’s seminar last summer.
Photo courtesy of Barbara Rossing.
To see the explosion of abundant life 510 million years ago was stunning. It was even more stunning to realize that the evolutionary lineage of nine-tenths of the creatures that made up the Cambrian tree of life did not continue. Only the descendants of pikaia, one of the earliest animals structured with lateral symmetry on either side of a proto-backbone, survived extinction. Pikaia is the earliest known representative of the phylum to which we humans also belong.
The tree of life is a central image in many religions: the Bodhi Tree at the axis of the world in Buddhist cosmology, the Iroquois tree whose roots hold together the whole world, the Jewish menorah, the Shaker Tree of Life of early American utopian spirituality.
The Bible starts and ends with the tree of life. In the Gospel of John, the tree becomes the image of Jesus as a vine, with all his followers imagined as branches of the vine (John 15). In the apocalyptic book of Revelation, the tree of life bears medicinal leaves for healing the world (Rev 22:2).
Charles Darwin first sketched the model of a branching tree of life to show the biological community of relationships, placing humans at the top of the tree.
In the 20th century, the image became a kind of sideways tree, with three principal groups—eukaryotes (humans and all multi-cellular organisms) plus two single-cell groups, the archaea and bacteria.
With genome sequencing, the tree of life model was transformed into a circular tree, with lines across the circle to show genetic relationships among organisms.
The latest model looks more like a tree again, but without a trunk. We humans share the same branch, at the bottom, with all multi-cellular organisms dating back to the Precambrian Era, more than 2 billion years ago.
It is dazzling to realize the abundance of the tree of life on Earth. As more genomes are sequenced and new species discovered, the model will likely change again. The tree of life shows the kinship of all creation and the cosmos.
My research explores how the biological and religious trees of life can serve us theologically, as correctives to overly individualistic religious understandings of our place on Earth. The tree of life reminds us that we humans are who we are thanks to a community of relationships, in mystical communion with God, with one another, and with every living cell and creature throughout the universe's history.
The tree of life can also help us envision our future. Hope for the future—the theological category sometimes called "eschatology"—plays a vital role in people's religious and spiritual life. When we can imagine our future, then we are able to move toward it with hope. Some medieval strands of Christian eschatology focused people's imagination individualistically on the “four last things”—death, judgment, heaven, and hell. Today, however, I believe religious imagination about the future needs to focus more on hope and healing, reconciliation, and life in a community of relationships—perhaps even expanding our vision of the communion of saints.
Throughout the history of Christian art, the tree of life has given people an image for linking their own lives and landscapes to biblical landscapes and communities. The tree of life was an image of mystical communion, helping people imagine the rivers and trees of paradise already in their daily lives. The stained glass Jesse Tree window of Chartres Cathedral depicts the lineage of Jesus as a tree growing out of the side of Jesse, with all his biblical ancestors in the branches. The "gift drawings" of Shaker artist Hannah Cohoon (1788-1864) imaged the community's life as a fruit-bearing tree of life, revealed in spiritual visions.
In Revelation, the Bible's most Earth-centered eschatological vision, the tree of life became an image of healing, reconciling the whole world. Today, this expansive eschatological image of healing can speak to individuals, to relationships, to communities struggling against injustice, and to the many illnesses of our world. In the face of climate change and other grave perils, the tree of life—with leaves of medicine for the world's wounds—inspires a vision of hope for future life on Earth.
©Kristen Jordahl Gilje, used with permission. Contact at firstname.lastname@example.org.
The goal of my project's research on eschatology and the tree of life is not to replace deeply held traditional hopes of heaven. I hope to strengthen people's hope for the future by laying alongside heaven a more immanent eschatology of lasting life on Earth, illuminated by insights from the natural sciences, environmental studies, social sciences, literature, and art. The new tree of life drawn by scientists gives us new visions for religious community today.
Read a Q&A with Barbara Rossing about her research here.
Header photo by Laura A. Hug, Brett J. Baker, Karthik Anantharaman, Christopher T. Brown, Alexander J. Probst, Cindy J. Castelle, Cristina N. Butterfield, Alex W. Hernsdorf, Yuki Amano, Kotaro Ise, Yohey Suzuki, Natasha Dudek, David A. Relman, Kari M. Finstad, Ronald Amundson, Brian C. Thomas and Jillian F. Banfield, via Wikimedia Commons.