{"id":49562,"date":"2026-09-12T15:14:13","date_gmt":"2026-09-12T15:14:13","guid":{"rendered":"https:\/\/gpnewswire.com\/news\/why-leaves-change-color-and-how-we-become-who-we-are-the-science-of-chlorophyll-and-the-poetics-of-personhood\/"},"modified":"2026-09-12T15:14:13","modified_gmt":"2026-09-12T15:14:13","slug":"why-leaves-change-color-and-how-we-become-who-we-are-the-science-of-chlorophyll-and-the-poetics-of-personhood","status":"publish","type":"post","link":"https:\/\/gpnewswire.com\/news\/why-leaves-change-color-and-how-we-become-who-we-are-the-science-of-chlorophyll-and-the-poetics-of-personhood\/","title":{"rendered":"Why Leaves Change Color and How We Become Who We Are: The Science of Chlorophyll and the Poetics of Personhood"},"content":{"rendered":"

\u201cWe reach forth and strain every nerve, but we seize only a bit of the curtain that hides the infinite from us.\u201d <\/h3>\n
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Autumn is the season of ambivalence and reconciliation, soft-carpeted training ground for the dissolution that awaits us all, low-lit chamber for hearing more intimately the syncopation of grief and gladness that scores our improbable and finite lives \u2014 each yellow burst in the canopy a reminder that everything beautiful is perishable, each falling leaf at once a requiem for our own mortality and a rhapsody for the unbidden gift of having lived at all. That dual awareness, after all, betokens the luckiness of death<\/a>.<\/p>\n

\"\"<\/a>
Art by Arthur Rackham, 1906. (Available as a print<\/a>.)<\/figcaption><\/figure>\n

But autumn is also the season of revelation, for the seeming loss unveils a larger reality: Chlorophyll is a life-force but it is also a cloak, and when trees shed it from their leaves, nature\u2019s true colors are revealed. <\/p>\n

Photosynthesis is nature\u2019s way of making life from light. Chlorophyll allows a tree to capture photons, extracting a portion of their energy to make the sugars that make it a tree \u2014 the raw material for leaves and bark and roots and branches \u2014 then releasing the photons at lower wavelengths back into the atmosphere. A tree is a light-catcher that grows life from air.<\/p>\n

Although the human mind has puzzled over why leaves fall and change color at least as far back as Aristotle, chlorophyll \u2014 which shares chemical kinship with the hemoglobin in our blood \u2014 was only discovered and named in 1817, by the French pharmacist-chemist duo Joseph Bienaim\u00e9 Caventou and Pierre Joseph Pelletier. In a lovely touch of humility that distinguishes, always, the scientist from the explorer \u2014 the explorer, so eager to name the lands and landmarks he has \u201cdiscovered\u201d after himself \u2014 they wrote in their landmark paper:<\/p>\n

\n

We have no right to name a substance long-known, and to the story of which we have added only a few facts; however, we will propose, without granting it any importance, the name chlorophyll, from chloros<\/em>, color, and \u03c6\u03c5\u03bb\u03bb\u03bf\u03bd, leaf: a name that would indicate the role it plays in nature.<\/p>\n<\/blockquote>\n

\"\"<\/a>
Red maple by Clarissa Munger Badger, who inspired Emily Dickinson<\/a>. (Available as a print<\/a> and as stationery cards<\/a>, benefitting The Nature Conservancy.)<\/figcaption><\/figure>\n

But chlorophyll, which is yet to be fully understood, is not the only pigment in trees. Throughout a leaf\u2019s life, four primary pigments course through its cells: the green of chlorophyll, but also the yellow of xanthophyll, the orange of carotenoids, and the reds and purples of anthocyanins. <\/p>\n

In spring and summer, when the days grow long and bright, chlorophyll saturates leaves as the tree busies itself converting photons into the sweetness of new growth. <\/p>\n

As daylight begins fading in autumn and the air cools, deciduous trees prepare for wintering<\/a> and stop making food \u2014 an energy expenditure too metabolically expensive in the dearth of sunlight. Enzymes begin breaking down the decommissioned chlorophyll, allowing the other pigments that had been there invisibly all along to come aflame. And because we humans so readily see in trees metaphors for our emotional lives<\/a>, how can this not be a living reminder that every loss reveals what we are made of \u2014 an affirmation of the value of a breakdown<\/a>?<\/p>\n

\"\"<\/a>
Life and Loss Are One<\/em> by Maria Popova. (Available as a print<\/a> and as stationery cards<\/a>, benefitting The Nature Conservancy.)<\/figcaption><\/figure>\n

A similar process take place as fruit ripen from green to varying shades of red, purple, orange, or yellow. <\/p>\n

Two centuries after the discovery of chlorophyll, a new generation of scientists armed with a new arsenal of tools unimaginable in 1817, in that abiding way science has of only revealing new layers of reality when it lets go of its assumptions<\/a>, placed bananas in various stages of ripeness under UV light<\/a> and discovered that as the world\u2019s favorite yellow fruit ripens and its chlorophyll breaks down, it not only reveals the xanthophyll of yellow, but produces the chlorophyll catabolite hmFCC<\/em> \u2014 a previously unknown blue fluorescent compound. <\/p>\n

\"\"
Artwork based on laboratory imaging from Angewandte Chemie: A Journal of the German Chemical Society<\/em>, international edition, 2008.<\/figcaption><\/figure>\n

Subsequent research<\/a> has found signs of this blue pigment in devil\u2019s ivy \u2014 the evergreen golden pothos thriving in the corner of my library in Brooklyn at this very moment \u2014 rendering the mystery of chlorophyll ongoing and filling the human heart with exhilaration. How thrilling to think that something we discovered two centuries ago, something nature created more than a billion years ago when the first green plants evolved from prokaryotes, can still shimmer with mystery \u2014 a molecular microcosm of the ultimate thrill: the knowledge that however much we might uncover, nature will never cease to be filled with surprise ripe for the reaping. And how humbling to think that we too are animals doing their best to make sense of the world with their creaturely limitations \u2014 animals whose vision evolved to peak in so narrow a band of the spectrum, in the tiny wavelength range between red and violet, blind to everything between radio and cosmic rays, blind to ultraviolet light. But if we were butterflies or reindeer, bees or sockeye salmon, bananas might be blue. <\/p>\n

\"\"<\/a>
\u201cSpectra of various light sources, solar, stellar, metallic, gaseous, electric\u201d from Les ph\u00e9nom\u00e8nes de la physique<\/em><\/a> by Am\u00e9d\u00e9e Guillemin, 1882. (Available as a print<\/a> and as a face mask<\/a>.)<\/figcaption><\/figure>\n

The poetic astronomer Maria Mitchell<\/a> captured this best in her rueful and rapturous observation that \u201cwe have a hunger of the mind which asks for knowledge of all around us, and the more we gain, the more is our desire,\u201d and yet \u201cwe reach forth and strain every nerve, but we seize only a bit of the curtain that hides the infinite from us.\u201d <\/p>\n

Complement with the late, great nature writer Ellen Meloy on the conscience of color from chemistry to culture<\/a>, then revisit this fascinating read on Turing, trees, and the science of how alive you really are<\/a>.<\/p>\n

\n

donating = loving<\/h3>\n

For seventeen years, I have been spending hundreds of hours and thousands of dollars each month composing The Marginalian<\/em> (which bore the outgrown name Brain Pickings<\/em><\/a> for its first fifteen years). It has remained free and ad-free and alive thanks to patronage from readers. I have no staff, no interns, no assistant \u2014 a thoroughly one-woman labor of love that is also my life and my livelihood. If this labor makes your own life more livable in any way, please consider lending a helping hand with a donation<\/a>. Your support makes all the difference.<\/p>\n

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newsletter<\/h3>\n

The Marginalian<\/em> has a free weekly newsletter. It comes out on Sundays and offers the week\u2019s most inspiring reading. Here\u2019s what to expect<\/a>. Like? Sign up.<\/a><\/p>","protected":false},"excerpt":{"rendered":"

\u201cWe reach forth and strain every nerve, but we seize only a bit of the curtain that hides the infinite from us.\u201d Autumn is the season of ambivalence and reconciliation, soft-carpeted training ground for the dissolution that awaits us all, low-lit chamber for hearing more intimately the syncopation of grief and gladness that scores our […]<\/p>\n","protected":false},"author":1,"featured_media":49563,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[43],"tags":[],"class_list":["post-49562","post","type-post","status-publish","format-standard","has-post-thumbnail","category-life"],"publishpress_future_action":{"enabled":false,"date":"2026-10-25 12:15:02","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/posts\/49562","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/comments?post=49562"}],"version-history":[{"count":0,"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/posts\/49562\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/media\/49563"}],"wp:attachment":[{"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/media?parent=49562"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/categories?post=49562"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gpnewswire.com\/news\/wp-json\/wp\/v2\/tags?post=49562"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}