Muir: advocate for the wild

At a bookstore in Portland in July I purchased a biography of John Muir by history professor Donald Worster. An excellent book, I gradually read it over the last few months. For a decade Muir has been a significant role model for me. My first substantive introduction to his writing was towards the end of graduate school when my mom bought me a book with a collection of his writings. Muir's romantically-infused view of nature, his attentiveness to natural history details, his wit regarding our own species, and his deep love of nature's beauty all resonate deeply with me.

President Teddy Roosevelt and John Muir at Glacier
Point overlooking Yosemite Valley in 1906. Image
in the public domain.

Muir is widely regarded as the godfather of Yosemite, of the National Park System, and of wilderness as a human value. He grew up in Scotland in a stern religious household, immigrated with his family to Wisconsin during childhood, and began to study science at the University of Wisconsin, though he did not complete his degree. The youthful Muir was an inventor and interested in mechanical innovation and efficiency. For instance, he built several versions of an alarm-clock bed that would rudely tip him to his feet at the appointed time early in the morning! His early career was spent in factories where his proclivity towards innovation bore fruit, but that left less time for indulging in his interests in science. An alarming accident in the factory that nearly blinded him helped him re-evaluate his life’s direction. Muir soon thereafter gave up factory work, moved to California – and scarcely giving any attention to the shiny city of San Francisco where his ship landed – headed for the Sierra Nevada.

Muir would end up spending years living in and exploring Yosemite and the nearby Sierra range. Though he lacked higher academic credentials, he would eventually help decipher from the rocks that the great valleys of the Sierra were formed by the slow action of glaciers, even though leading geologists of the time tended to favor other, incorrect theories. Muir also traveled beyond his beloved Yosemite to other regions of the west - to Mt. Rainier, to the Great Basin, and on seven different trips, to the recently acquired US territory of Alaska.

A panorama of forest in Sequoia National Park, August 2014. Crowns of giant sequoias (Sequoiadendron giganteum) in Muir Grove can be seen at top center. From a glacier to a wilderness area in the Sierra, to a beach, Muir has numerous natural landmarks named after him throughout the western United States.

Worster’s biography shed some light on aspects of Muir's life that I didn’t know or that I under-appreciated. By hard work and financial thrift, he gradually grew into a life of significant financial and social comfort by his later years. This was an interesting point of contrast for a man who was perfectly happy to sleep outside below the stars or who packed little but tea and bread for several days of wandering in the wilderness. In addition to his exploration throughout the western US, he also took several long international journeys (traveling to most continents) and he spent a significant amount of time in the deserts of the southwest, though he is mainly known as the patron saint of the Sierra. Finally, I learned that he actually camped with not one, but two, US Presidents who made visits to California (Roosevelt and Taft).

Muir's life was a celebration of nature, and on the time scale of history he had a tremendous impact on conservation and natural resource protection, but his life ended on a sad note. For years, he was involved with others in a political battle to save the beautiful Hetch Hetchy valley in Yosemite National Park from drowning under San Francisco's uncompromising push for urban growth and consumption. For a time it seemed that the proposed dam Muir strongly opposed would be put on hold for at least a generation, but in the end other political forces prevailed and Yosemite Valley’s northerly twin granite cathedral was allowed to drown to become a reservoir. The valley remains underwater today.

Muir epitomized aesthetic love of nature, but he was a pragmatist too and did not object to mankind’s use of natural resources or natural areas. His lifetime spanned a great period of technological and engineering advances (the mid 1800s to early 1900s), which perhaps accelerated the pace and degree to which human intervention in the natural world could leave lasting imprints. He was favorable to industrial advances, but he advocated for a much greater emphasis on conservation than most of his contemporaries. He didn’t see industrial or agricultural progress as an enemy, but rather recognized that true human progress depended on a deep reverence for, and sufficient protection, of nature. Today, he would likely be astounded at just how far humankind has impacted every ecosystem on earth, but perhaps he would also be relieved that his successors have set aside some of the most inspiring natural places as wildernesses and national parks.

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I stumbled upon Muir’s old mansion in Martinez, California inadvertently this summer while car shopping. Just off the highway, a National Park Service sign appeared across the road which marked the house and orchards where Muir spent the last decades of his life. It was originally owned by his father-in-law but eventually came to be owned by the naturalist. After an uneventful visit to the car dealership, we stopped at the visitor’s center and then toured the house and grounds.

The Muir mansion in Martinez, California. The photo at right is Muir's office, which he called his "scribble den".

The Muir-Strentzel mansion is perched on the top of a small hill. It is spacious with several stories, a large kitchen, a green-house like room on the east side of the building, and a small bell tower. There are fancy chandeliers. Muir had an office on the second floor across from his bedroom where a desk sat below windows that open up to the Alhambra Valley to the north. Here he worked on patching together old field notebooks and other scraps of text into the wonderful nature writing we have today.

Out on the grounds the fruit trees have been preserved by the Park Service, perhaps including some of the original trees that Muir, his family, and hired workers tended. He was a successful and hard-working business man, turning a good profit on the property. The mansion and grounds are not the expected scene of a lover of all things wild. Yet, down the slope from the house also grows a single tall Sequoiadendron giganteum specimen too, planted by Muir.

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Writing apparently came with great difficulty to Muir, though in books like My First Summer in the Sierra, I've felt his words flow with grace and ease. He frequently used superlatives, even religious language, to describe the landscapes impressed on his mind. To Muir, the geologic labor that built cathedrals like the Yosemite Valley was superior to anything humankind could construct. His early writings consisted of articles for periodicals published on both the east and west coasts. He was able to introduce the marvelous natural areas of the west to eastern readers who had never seen the less-densely populated areas of western North America. His books tended to emerge later in his life (or even shortly after his death); in some cases they were re-workings of his shorter essays.

A photo of Hetch Hetchy Valley in Yosemite National Park taken by Isaiah
Taber in the first decade of 1900s, before the valley was flooded. Image in
the public domain.

One of the refreshing hallmarks of Muir’s writings is his near complete avoidance of politics, and even of human actors and voices. He was intimately involved in the politics of conservation towards the end of his life, but that was a necessary evil to protect his beloved wild places, not a manifestation of a propensity towards the political life. Muir’s pen focused on nature, and if there is a lesson to be had from his approach for my own attempts to write about nature, it is the power of letting the organisms have the main voice in the narrative.

Muir had a profoundly different perspective on the natural world than many of his contemporaries, or even of many people alive today. As I came to the conclusion of Worster’s biography, it seemed to me that Muir's greatest concern over how humans interacted with nature was the inability of most to see beyond money. Such a narrow focus could afflict both the poor and the rich of his day - the rich because they were willing to sacrifice the irreplaceable beauty of nature for short-term monetary gain, and the poor because they were confined to a system that kept them focused on economic concerns for their very daily survival. Muir advocated for recognizing the true wealth of nature and its irreplaceable value to humankind. Nature is the wealth of eons of history, accumulated by slow but ruthless and elegant forces of biology and geology. Nature reminds us of what is insignificant and unimportant. Nature inspires our aesthetic and spiritual aspirations as a species.

“How fiercely, devoutly wild is Nature in the midst of her beauty-loving tenderness! – painting lilies, watering them, caressing them with a gentle hand, going from flower to flower like a gardener while building rock mountains and cloud mountains full of lightening and rain. Gladly we run for shelter beneath an over-hanging cliff and examine the reassuring ferns and mosses, gentle love tokens growing in cracks and chinks. Daisies too, and ivesias, confiding wild children of light, too small to fear. To these one’s heart goes home, and the voices of the storm become gentle. Now the sun breaks forth and fragrant steam arises. The birds are out singing on the edge of the groves. The west is flaming in gold and purple, ready for the ceremony of the sunset, and back I go to camp with my notes and pictures, the best of them printed in my mind as dreams.” John Muir, 20 July 1869, My First Summer in the Sierra.

References

Muir J. 1911. My First Summer in the Sierra. Penguin Books.

Worster D. 2008. A Passion for Nature. The Life of John Muir. Oxford University Press.

So it turns out to be a threesome

Lichens are amazing organisms, drawing out our curiosity both because of their aesthetic appeal and their novel ecological and evolutionary characteristics. For over a hundred years, biologists have supposedly known about their basic composition: they are one of nature’s best examples of a symbiosis, a tight coupling of two or more evolutionarily distinct organisms that can function like a single unit. In the case of lichens, the two coupled organisms are a fungus and a photosynthetic alga.

Encrusting lichens at Newberry National Monument, Deschutes Co., OR, June 2011.

That basic understanding of lichens as an evolutionary marriage between alga and fungus remains fact. However, a paper published this summer significantly expanded the overall picture. Lead author Toby Spribille and his colleagues provide evidence in the journal Science that many lichens are symbioses of not just two groups of organisms, but three! How could such a basic aspect of lichen biology go undetected for so long?

Letharia vulpina on tree bark at Diamond Peak
Wilderness, OR, May 2013.

Their surprising discovery came about by careful observation and testing of what might otherwise pass as a rather mundane question in lichen biology. The authors were investigating differences in two closely related species of lichen, Bryoria tortuosa and B. fremontii. The former species produces a compound called vulpinic acid that causes the lichen to have a yellowish color. B. fremontii, however, lacks (or has reduced production of) the acid and is brown in color. What had baffled researchers, however, was the failure to find genetic differences between the two supposed species. Both the ascomycete fungus and the photosynthetic partner (a green alga called Trebouxia simplex) in the two species had identical sequences when several genes were studied. Species are expected to have fixed genetic differences even if their phenotype (their appearance) is very similar.

Spribille and colleagues decided to study the genetic structure again of the two species by sequencing the mRNA transcriptome. They confirmed the genetic similarity that had been observed before and also found little difference in gene expression between B. tortuosa and B. fremontii. However, when the researchers broadened their search to consider whether the transcripts they sequenced might match any other types of fungi, they found that the acid-producing B. tortuosa produced sequences associated with basidiomycetes, a very different group of fungi than are typically seen in lichens. The evidence pointed to a third symbiont in B. tortousa!

Apothecia (spore-producing structures) on encrusting lichens. Left: Alpine bloodspot, Ophioparma ventosa, Deschutes National Forest, OR, May 2012. Right: Ochrolechia sp., Bear Valley, Tahoe National Forest, CA, Dec 2009.

Usnea longissima, hanging from a vine maple in the
Menagerie Wilderness, Linn Co., OR, Oct 2012.

With this new finding, the researchers asked whether other lichen species might potentially harbor basidiomycetes as well. Surveying a variety of other lichen lineages, they found basidiomycete sequences in 52 different genera distributed across six continents! The basidiomycete lineages in the lichens seemed to be diverse group of fungi, but they were associated with specific species. The new group of basidiomycete symbionts is called the Cyphobasidiales.

Up until now, it had been known that some lichens deviated from the classic model of two partners in the lichen symbiosis. For instance, some species have two algal hosts in addition to the fungal partner – both a green alga and a cyanobacterium (Henskens et al. 2012). However, Spribille et al.’s research suggests that the typical lichen association is made up of two distinct fungal lineages and one or two algae. Thus, lichens may typically be threesomes, and sometimes, even foursomes. As if this wasn’t complicated enough, DNA sequencing work by Bates et al. (2011) showed that lichens can also have bacterial communities associated with them. They found unique groups of alpha proteobacteria associated with the lichen body in 4 species they studied. Apparently the more that lichens are studied, the more we could describe these remarkable organisms as comprising their own little ecological worlds!

The lichen Cladonia in a residential yard, Humboldt
Co., CA, Dec 2009.

With the relative ubiquity of the third symbiont evident in sequence data, why haven’t previous researchers seen these basidiomycete symbionts when looking through the microscope at lichen specimens? It turns out that the cells are difficult to detect by microscopy. They are small, and on the periphery of the lichen body, being embedded in a matrix of polysaccharides. Using florescent molecular tags on rRNA sequences specific to the basidiomycete partner, however, the new cells and their location in the lichen thallus (body) became readily apparent.

Interestingly, the new results explain one of the mysteries that lichen biologists have confronted for a long time, namely that it has been difficult to recreate the lichen symbiosis in the lab by combining only a single fungal host and alga. The typical lichen shape was hard to reproduce with only two partners.

It is fascinating to ponder the evolutionary history that could lead to such a complex and intimate association of distinct organisms. Green algae, cyanobacteria, and fungi are not closely related. During the early evolution of lichens, how did algae first become associated with the body of fungi? Did early lichens start with two fungal partners plus an alga, or were today’s lichen ancestors more simple in composition?

Lichens covering a rock in coastal scrub near
Muir Beach, Marin Co., CA, Oct 2016.

Whatever the exact evolutionary sequence of events, the lichen symbiosis appears to have proved to be very successful in terms of survival and reproductive success. In fact, fossils suggest that associations of algae and fungi are at least a half billion years old, stretching back to about the time that invertebrate animals diversified in the Cambrian Explosion, and before the arrival of vascular plants on land (Yuan et al. 2005). Today, there are many thousands of species of lichens, inhabiting ecosystems as diverse as deserts, coniferous rainforests, and coastlines.

References

Bates ST, Cropsey GW, Caporaso JG, Knight R, Fierer N. 2011. Bacterial communities associated with the lichen symbiosis. Applied and Environmental Microbiology 77:1309-1314.

Brodo IM, Sharnoff SD, Sharnoff S. 2001. Lichens of North America. Yale University Press.

Henskens FL, Green TG, Wilkins A. 2012. Cyanolichens can have both cyanobacteria and green algae in a common layer as major contributors to photosynthesis. Annals of Botany 110:555-563.

Spribille T, Touvinen V, Resl P, et al. 2016. Basidiomycete yeasts in the cortex of ascomycete lichens. Science 353:488-492.

Yuan X, Xiao S, Taylor TN. 2005. Lichen-like symbiosis 600 million years ago. Science 308:1017-1020.

Lichen (perhaps Amandinea) on wood fence, Pt. Reyes National Seashore, CA, Nov 2008.

Fruticose lichen in redwood forest, Van Duzen County Park, Humboldt Co., CA, 2006.