#humanevolution — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #humanevolution, aggregated by home.social.
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A Neanderthal got a tooth drilled 59,000 years ago — with a jasper perforator, no anesthetic, and it worked. New research from Chagyrskaya Cave just rewrote the history of dentistry. #Neanderthal #Paleoanthropology #HumanEvolution #Dentistry #Tooth https://www.anthropology.net/p/a-neanderthal-had-a-tooth-drilled
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The Ascendents
Ancestry, Memory, Humanity, and the Upward Calling of the Living
Ascendent by kmlsWe have been taught to say that we are descended from those who came before us.
The word is not wrong. It is genealogically useful. It traces the stream from the spring, the branch from the trunk, the child from the parent, the living from the dead. It tells us that we are not self-made, not self-originating, not isolated sparks floating in the void. We come from somewhere. We are carried into being by names, bloodlines, migrations, accidents, loves, wounds, prayers, hungers, wars, fields, fires, and forgotten hands.
Yet the word troubles me.
For to say that we are descended may also suggest a downward motion, as though we have fallen from some ancestral height. It can feel as if the past stands above us in solemn judgment, and we, the living, are merely the lower remainder: diminished copies, scattered seed, thin-blooded heirs of stronger people.
We speak of descent as if we are always coming down.
Down from the fathers.
Down from the mothers.
Down from the old country.
Down from Eden.
Down from glory.
Down from the dead.But what if the truth is not only that we descend from them?
What if we ascend from them?
What if we are not the falling away of our ancestors, but their rising continuation?
What if we are the place where the buried become conscious, where the forgotten become remembered, where the unfinished become possible, where the dead are not merely behind us but beneath us — not as a weight dragging us downward, but as roots pressing life upward through the dark?
To be human is not simply to be descended.
To be human is to be ascendent.
Not ascendant in the arrogant sense. Not ascendant as empire is ascendant, not as a conqueror ascends a throne, not as a nation ascends by trampling another underfoot, not as wealth ascends by feeding upon the poor, not as the celebrated ascend by making the nameless disappear.
That is false ascendancy.
That is Babel.
That is the tower built upward by those who refuse to look downward at the bodies embedded in its bricks.
The ascendancy I mean is humbler, older, stranger, and holier. It is the rising of life from soil. It is the green blade through the graveyard. It is memory becoming mercy. It is grief becoming wisdom. It is ancestry becoming vocation.
We are not above our ancestors because we are better than they were.
We are above them because they are beneath us as foundation.
The child stands higher than the parent only because the parent has bent low.
The living stand higher than the dead only because the dead have become earth.
Every generation is lifted by those who are no longer visible.
This is the first doctrine of the Ascendents: we rise from what has been buried.
We rise from bodies and stories. We rise from names spoken and names erased. We rise from villages burned and fields planted. We rise from ships, cabins, kitchens, trenches, meetinghouses, reservations, prisons, refugee roads, hospital rooms, schoolhouses, barns, factories, cemeteries, and quiet beds where the dying whispered blessings no one wrote down.
We rise from all of it.
Not only from glory.
Not only from virtue.
Not only from noble sacrifice.We rise also from sin.
This is what makes ascent morally dangerous.
For our ancestors do not hand us only wisdom. They hand us wounds. They do not give us only courage. They give us cowardice disguised as prudence, prejudice disguised as tradition, violence disguised as necessity, greed disguised as providence, silence disguised as peace.
To be ascendent is not to romanticize the past.
It is to redeem it by telling the truth.
A person who worships their ancestors remains trapped beneath them. A person who despises their ancestors cuts themselves off from their own roots. But a person who honors their ancestors truthfully becomes capable of rising.
Honor is not flattery.
Honor is not nostalgia.
Honor is the severe mercy of remembrance.
To honor those before us is to receive what was good, repent of what was evil, grieve what was broken, and carry forward what was unfinished.
We are the living edge of their becoming.
We are their unresolved sentence.
We are their prayer still traveling.
We are their question still being answered.
This means that the past is not dead in the simple way we imagine. It is not gone merely because the bodies are gone. The past continues to move through us as habit, language, land, fear, blood pressure, lullaby, recipe, doctrine, posture, accent, suspicion, hope, inheritance, and unexamined reflex.
History does not stay in books.
History enters the nervous system.
A war may end, yet its tremor continues in the children of the children of those who survived it. A displacement may be recorded as an event, yet the hunger for home may live for centuries. A massacre may be omitted from the official monument, yet the ground remembers. A church may repent in words while its architecture still faces the wrong direction. A family may never speak of grief, yet every child learns how to lower the voice around sorrow.
The dead are not silent.
They speak in us.
The question is whether we will listen.
The Ascendent is one who listens downward in order to live upward.
This is not ancestor worship. It is ancestor responsibility.
Nor is it progressivism in its shallow form. Progress, as commonly preached, often imagines time as a ladder on which the present naturally stands above the past. It assumes that because we come later, we must be wiser. This is foolishness. Chronology is not sanctification. The future can be more brutal than the past. Technology can amplify barbarism. A people may move forward in time while moving backward in soul.
No, ascent is not automatic.
Humanity does not rise merely by surviving.
We rise only when remembrance becomes transformation.
We rise when the grief of one generation becomes the compassion of the next.
We rise when the violence of one generation becomes the refusal of the next.
We rise when the silence of one generation becomes the testimony of the next.
We rise when the buried cries of the forgotten become the moral hearing of the living.
“The blood of your brother cries out from the ground.”
That ancient sentence is the foundation of all history.
The ground is not mute. The earth is not neutral. Soil is archive. Dust is witness. Every field has its dead. Every town has its omitted chapter. Every nation has its sanctified lie. Every family has its locked room. Every monument has a shadow. Every victory has a graveyard of the unnamed.
The Ascendent does not merely ask, “Who were my ancestors?”
The Ascendent asks, “Whose blood is beneath my feet?”
Not because guilt is the final word.
Guilt alone can paralyze. Shame alone can distort. Accusation alone can become another form of vanity, where the living make themselves dramatic by endlessly displaying the wounds of the dead.
The purpose of remembering is not to become impressive in our sorrow.
The purpose of remembering is to become faithful in our living.
To be ascendent is to understand that I am not an isolated self. I am a crossing point. I am a confluence. I am made of many streams, some clear, some polluted, some holy, some poisoned, all meeting in the temporary river of my life.
My task is not to pretend the waters are pure.
My task is to help them run cleaner through me.
This may be the deepest meaning of repentance: not self-hatred, but generational purification. Not the rejection of one’s people, but the healing of what one has received from them. Not a descent into despair, but an ascent into truth.
Repentance is how ancestry becomes possibility.
Without repentance, inheritance becomes repetition.
Without remembrance, repentance becomes vague.
Without love, remembrance becomes accusation.
Without courage, love becomes sentiment.
The Ascendent must hold all four together: remembrance, repentance, love, and courage.
Only then can the past become seed rather than chain.
There is also a personal meaning here.
Each of us carries within ourselves earlier selves. The child, the adolescent, the wounded one, the ambitious one, the ashamed one, the hopeful one, the foolish one, the frightened one, the one who failed, the one who survived. We often speak as if we have descended from those selves into disappointment. We look back and say, “I was once more alive. I was once more promising. I was once closer to what I might have been.”
But perhaps we also ascend from our former selves.
Perhaps every earlier self, even the embarrassed and broken ones, is part of the root system.
I rise from the child who dreamed.
I rise from the young person who misunderstood.
I rise from the failure that humbled me.
I rise from the wound that opened me.
I rise from the grief that deepened me.
I rise from the fear that taught me how much I needed grace.
Nothing is wasted if it can be transfigured.
This does not mean everything was good. Some things were evil. Some things should not have happened. Some wounds are not secret blessings. Some suffering does not ennoble; it damages. Some losses remain losses.
But even what cannot be justified may still be gathered.
Even what cannot be called good may still be refused the final word.
The Ascendent does not say, “All things were good.”
The Ascendent says, “Even here, I will rise.”
Not by denial.
By truth.
Not by domination.
By integration.
Not by forgetting.
By carrying.
This is why ascent is not escape. It is not floating away from the earth into disembodied purity. True ascent is rooted ascent. The tree rises because it goes down. The mountain ascends because it is grounded. The resurrected body still bears scars.
Any spirituality that rises by abandoning the wounded is not ascent but evasion.
Any politics that rises by erasing the poor is not ascent but conquest.
Any theology that rises by despising the body is not ascent but contempt.
Any family story that rises by silencing the inconvenient dead is not ascent but propaganda.
The true Ascendent rises with scars visible.
This is where humanity stands.
We are a species that has learned to fly but not yet learned to kneel. We have ascended into the air, into orbit, into code, into machines of astonishing power, yet our moral imagination often remains tribal, fearful, acquisitive, and easily bewitched by idols. We can split the atom and still cannot share bread. We can map the genome and still cannot honor the stranger. We can remember data forever and forget the dead almost instantly.
So the question is not whether humanity is technologically ascendant.
The question is whether humanity is morally ascendent.
Will we rise from our ancestors or merely repeat them with better tools?
Will we carry forward their wisdom or only refine their weapons?
Will we remember the forgotten or continue to build monuments to the victorious?
Will we become more human, or only more powerful?
The Ascendents are not those who dominate history.
They are those who redeem memory.
They are the ones who refuse to let the common dead remain common in the sense of disposable. They remember the foot soldier beside the general, the farmer beside the statesman, the Indigenous village beneath the colonial map, the mother beneath the family name, the enslaved beneath the plantation ledger, the child beneath the statistic, the refugee beneath the border argument, the prisoner beneath the ideology, the enemy beneath the uniform.
They understand that every human being is an ancestor of the future.
This is a terrifying thought.
How will the future ascend from us?
What soil are we becoming?
Will our lives be root or rubble?
Will those who come after us have to heal from us, or will they be strengthened by us?
Surely both.
We too will hand down contradiction. We too are mixed. We too are capable of tenderness and harm, courage and cowardice, insight and blindness. The Ascendent is not pure. The Ascendent is accountable.
Perhaps that is the most we can ask of any generation: not purity, but accountability; not perfection, but faithful transformation; not innocence, but the courage to become better ancestors.
To be an Ascendent, then, is to live with one’s face turned in two directions.
One face turns downward toward the dead and says:
I remember you.
I receive you.
I grieve you.
I forgive what can be forgiven.
I name what must be named.
I will not pretend you were gods.
I will not pretend you were monsters only.
I will carry what was holy.
I will heal what was harmed.
I will not let your suffering vanish.
I will not let your sins rule me.The other face turns upward toward the unborn and says:
I am trying.
I am unfinished.
I am clearing what I can.
I am planting what I may never see.
I am refusing some inheritance so you need not bear it.
I am preserving some inheritance so you may be nourished by it.
I am becoming soil for your rising.This is the holy middle place of the living.
We are between the buried and the unborn.
We are the narrow bridge of breath between memory and hope.
We are the Ascendents.
Not because we have arrived.
Because we are called upward.
Not upward away from the world, but upward into fuller humanity.
Upward into mercy.
Upward into truth.
Upward into responsibility.
Upward into reconciliation.
Upward into the difficult radiance of becoming worthy of the dead.
And perhaps this is why the dead haunt us.
They do not haunt us merely because they are restless.
They haunt us because we are.
They haunt us because something in them remains unfinished in us. They haunt us because the lie has not yet been confessed, the grave has not yet been marked, the name has not yet been spoken, the wound has not yet become wisdom, the inheritance has not yet become blessing.
The haunting is not only terror.
It is vocation.
The dead rise in us so that we may rise from them.
And if we listen closely enough, beneath every field, beneath every town, beneath every family tree, beneath every national myth, beneath every human triumph, there is a murmuring from the ground. It is not only accusation. It is not only lament. It is also invitation.
Remember us.
Tell the truth.
Rise better.
Become what we could not.
Carry us toward the light.
So let us no longer say only that we are descended.
Let us say also that we are ascended from.
Ascended from dust.
Ascended from grief.
Ascended from labor.
Ascended from women whose names were not recorded.
Ascended from men who did not know how to speak their sorrow.
Ascended from children who died too soon.
Ascended from migrants, prisoners, farmers, singers, sinners, saints, cowards, prophets, fools, and friends.
Ascended from the blood that cried out.
Ascended from the prayers that rose before us.
Ascended from the earth that holds us all.And let us become, for those who follow, not a ceiling but a root.
Not a burden but a blessing.
Not a curse but a calling.
Not the final height, but one more living terrace on the long climb of mercy.
For humanity is not yet finished.
We are still rising.
We are still being judged by the dead.
We are still being summoned by the unborn.
We are still becoming the answer to our ancestors’ unanswered prayers.
We are The Ascendents.
#ancestors #ancestry #ascendents #becoming #creativeNonfiction #generationalHealing #grief #Hope #humanEvolution #Humanity #inheritance #memory #moralImagination #philosophy #PropheticEssay #reflection #remembrance #roots #sacredMemory #soilAndSpirit #SpiritualReflection #theDead #theUnborn #theologicalReflection #vocation -
This week's #NewBooks at the library: Another three books from our January clearance sale, some of which have been review candidates for some time now.
- Planet Palm: How Palm Oil Ended Up in Everything – and Endangered the World, a shocking and eye-opening reportage written by Jocelyn C. Zuckerman and published by Hurst Publishers.
- Making Faces: The Evolutionary Origins of the Human Face, written by Adam S. Wilkins, published by Belknap Press. Not one I was planning to review, but I find it very hard to pass up a bargain on an interesting book on human evolution and physical anthropology.
- Unfit for Purpose: When Human Evolution Collides with the Modern World, written by Adam Hart, published by Bloomsbury Sigma. One of several books that explores the mismatch between our evolutionary legacy and the modern world we have created for ourselves. I expect them to be amusing reads all!
#Books #Bookstodon #Scicomm #EnvironmentalIssues #PalmOil #PlantationForestry #FoodAdditives #Evolution #HumanEvolution #PhysicalAnthropology #Anatomy #PopularScience @bookstodon
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199 Indigenous American genomes. A third dispersal into South America. A ghost ancestry under selection for 10,000 years. The genomic scar of colonization. #Archaeogenetics #IndigenousAmerica #HumanEvolution https://www.anthropology.net/p/three-migrations-a-ghost-ancestry
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Redheads are ‘spreading across the globe’ as humans are still evolving | World | News
Britain’s Prince Harry may have done more to boost the profile of redheads than he has for the…
#NewsBeep #News #Health #Evolution #GB #geneticvariants #humanevolution #naturalselection #Redheads #UK #UnitedKingdom #Variant
https://www.newsbeep.com/uk/542048/ -
🧠 Cosa raccontano davvero i crani del Neolitico ligure?
Uno studio internazionale pubblicato nel 2026 svela una storia molto più complessa del previsto tra agricoltori e cacciatori-raccoglitori.📍 Dal Finalese emergono nuove risposte (e nuove domande) sulla preistoria europea
#Archeologia #Neolitico #Liguria #Preistoria #Antropologia #Ricerca #Scienza #HumanEvolution
I dettagli su Storie & Archeostorie: https://wp.me/p7tSpZ-cTZ
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A Neanderthal infant’s bones and teeth don’t agree on its age. The gap between them reveals something fundamental about how Neanderthals developed. New research in Current Biology. #Neanderthal #Paleoanthropology #HumanEvolution https://www.anthropology.net/p/the-neanderthal-infant-whose-bones
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There is still a chance to enter to win a copy of HUMAN at Storygraph!
A remarkable exploration of family, society, and what makes us human, HUMAN will take you from the post-apocalyptic world of the near future, to the two very different societies that emerge 15 million years later, where those few surviving individuals have evolved to become something that we might not fully recognize as human.
https://app.thestorygraph.com/giveaways/ce1477de-5fcc-4a27-891e-b87bb99e4c71
#HUMAN #WhatToRead #BookBlog #Readers #BrettHodnett #SpeculativeFiction #SciFi #WritersOfMastodon #SFF #SF #ScienceFiction #Author #Writer #Writers #Books #Livres #Bookstodon #HumanEvolution #PostApocalypse #ApocalypticFiction #Evolution #EPUB #Ebook #FreeBook #FreeBooks #GiveAway #Apocalypse #FediHuman
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Scientists still do not know what happened to our Neanderthal sisters and brothers.
But they're progressing fast. It's kind of gold rush atmosphere in this part of science cause there are so many new findings in such a short amount of time.
https://www.youtube.com/watch?v=dhSes-Io-kc
#Neanderthal #Evolution #HumanEvolution #Anthropology #HomoSapiens
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The disaster that never happened - Why interpretation of data is key. Cause the same data can tell very different stories. In fact: It's ourselves who tells the stories. Not the data.
https://www.youtube.com/watch?v=xJm22rmJsgg
#Science #Evolution #Human #Ancestry #Biology #HumanEvolution #Anthropology
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RE: https://fediscience.org/@tksst/116320252816874221
The list of human anatomical anomallies from other apes is a long list, but also, curiously, a list that either specifically matches or leans toward another species? 🤔
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One more day to get a free copy of my novel, HUMAN, on itch.io. Check it out!
https://bretthodnett.itch.io/human
#HUMAN #WhatToRead #BookBlog #Readers #BrettHodnett #SpeculativeFiction #SciFi #WritersOfMastodon #SFF #Finland #ScienceFiction #Author #Writer #Writers #Books #Livres #Bookstodon #HumanEvolution #PostApocalypse #ApocalypticFiction #Evolution #EPUB #Ebook #FreeBook #FreeBooks #GiveAway #Apocalypse #FediHuman
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Only a few days left to get a free copy of my novel, HUMAN, on itch.io. Check it out!
https://bretthodnett.itch.io/human#ScienceFiction #BooksOfMastodon #Book #Books #Fiction #EPUB #Ebook #FreeBooks #GiveAway #SciFi #Evolution #SpeculativeFiction #HumanEvolution #WhatToRead #Readers #WritingCommunity #Fediverse #Human #BrettHodnett #WritersOfMastodon #SFF #Author #Writer #Writers #Livres #Bookstodon #PostApocalypse #ApocalypticFiction #FreeBook #Apocalypse
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This week I’ll be offering my novel, HUMAN, for free on itch.io. I would encourage folks to support itch.io, an open marketplace for independent digital creators that doesn’t exploit artists or customers. HUMAN will remain on itch.io at a lower price than at other retailers after this free offering. I hope you enjoy it.
https://bretthodnett.itch.io/human
A remarkable exploration of family, society, and what makes us human, HUMAN will take you from the post-apocalyptic world of the near future, to the two very different societies that emerge 15 million years later, where those few surviving individuals have evolved to become something that we might not fully recognize as human.
When Ayla’s research takes her to a remote river in Canada’s far north, Chris brings their daughter to an isolated island in the southern Pacific. Though at opposite ends of the earth, they both awaken one morning to black skies, and a night that doesn’t end. Slowly, Ayla and Chris begin to realize that humanity has been inexplicably wiped out, and only their isolation has saved them. Besides the handful of people around them, they are now alone in the world. As they struggle to build new ways to live, they must also struggle with how to let go of their past.
Millions of years later, when their descendants finally meet, they have evolved to become two very different kinds of humans, with two very different civilizations. As each tries to build a better world for themselves, navigating love, loss, betrayal and success within their own societies, their biggest challenge may be to recognize the humanity of the other.
#HUMAN #WhatToRead #BookBlog #Readers #BrettHodnett #SpeculativeFiction #SciFi #WritersOfMastodon #SFF #SF #ScienceFiction #Author #Writer #Writers #Books #Livres #Bookstodon #BookCover #HumanEvolution #PostApocalypse #ApocalypticFiction #Evolution #EPUB #Ebook #FreeBook #FreeBooks #GiveAway #Apocalypse #FediHuman
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Scientists just digitally reconstructed the face of Little Foot, a 3.67-million-year-old Australopithecus from South Africa. The result looks more like East African fossils than local ones. Migration? Ancestral pattern? Still open. #Paleoanthropology #Australopithecus #HumanEvolution https://www.anthropology.net/p/little-foots-face-reconstructed-at
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In a dystopian world, slave owners have a breeding program to create slaves that willingly consent to be used and abused.
#slavery #consent #forcedlabor #humanbreeding #slavebreeding #dystopia #slaves #humanevolution #artificialselection #humanrights #fiction -
Flight & Brains, Feathers & Hair
June 03, 2020
Adaptation to flight has a big impact on antioxidant defenses; recently this paper came up in my feed:Adaptation of the master antioxidant response connects metabolism, lifespan and feather development pathways in birds [2020] - https://www.nature.com/articles/s41467-020-16129-4
“Birds (Aves) display high metabolic rates and oxygen consumption relative to mammals, increasing reactive oxygen species (ROS) formation. Although excess ROS reduces lifespan by causing extensive cellular dysfunction and damage, birds are remarkably long-lived. We address this paradox by identifying the constitutive activation of the NRF2 master antioxidant response in Neoaves (~95% of bird species), providing an adaptive mechanism capable of counterbalancing high ROS levels. We demonstrate that a KEAP1 mutation in the Neoavian ancestor disrupted the repression of NRF2 by KEAP1, leading to constitutive NRF2 activity and decreased oxidative stress in wild Neoaves tissues and cells. Our evidence suggests this ancient mutation induced a compensatory program in NRF2-target genes with functions beyond redox regulation—including feather development—while enabling significant metabolic rate increases that avoid trade-offs with lifespan. The strategy of NRF2 activation sought by intense clinical investigation therefore appears to have also unlocked a massively successful evolutionary trajectory.
The physiological risks of constitutive NRF2 activation due to loss of KEAP1 binding have been demonstrated in vivo through KEAP1 knockout mice, which die from starvation shortly after birth from hyperkeratosis of the gastrointestinal tract, likely through overexpression of α-keratins and loricrins in squamous cells (ref. 38; Fig. 4c). In addition to α-keratins, avian skin keratinocytes also express β-keratin genes, which combine with α-keratins to form avian skin appendages (feathers, scales, claws, beaks; ref. 3). ...
This strongly suggests that the NRF2-mediated regulation of β-keratins we detected in Chicken skin has been compensated for by the loss of AREs and downregulation of ARE binding by NRF2 at Neoaves β-keratin loci. This pattern closely mirrors the loss of NRF2-mediated ARE-regulation in Neoaves GSTA2 (Fig. 4b). Together these analyses provide in vivo evidence that the evolution of NRF2-associated feather development genes may have been shaped by the constitutive activation of NRF2 in Neoaves.”
This reminded me of some work on the evolution of large brain size in humans & loss of body hair:
Hair for brain trade-off, a metabolic bypass for encephalization [2014] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190188/
“Hair loss in humans is perplexing and raises many hypothetical explanations. This paper suggests that hair loss in humans is metabolically related to encephalization; and that hair covered hominids would have been unable to evolve large brains because of a dietary restriction of several amino acids which are essential for hair and brain development. We use simulations to imply that hair loss must have preceded increase in brain size & volume. In this respect we see hair loss as a major force in human evolution. We assume that hair reduction required favorable climatic conditions and must have been quick. Using evolutionary and ecological time scales, we pinpoint hair loss to a period around 2.2-2.4 million years ago. The dating is further supported by a rapid selection at that time of the sialic acid deletion mutation which may have protected growing human brains against calcium ion flux. In summary we view encephalization, in part, as a metabolic trade-off between hair and brain. Other biochemical changes may have intervened in the process too; and the deletion mutation of sialic acid hydroxylation may have been involved as well.
Human hair is composed of about 17% cysteine, a sulphuric amino acid noted for its ability to add rigidity to biological tissue (Table 3).”
Cysteine is also a major component of glutathione and a rate limiter for its synthesis; glutathione production is regulated through Nrf2. The Dror & Hopp 2014 paper mentions glutathione briefly; if the theory presented is correct, the increased need for glutathione synthesis is likely the major driver. In short, humans may have lost their body hair because of the increased demand for cysteine to produce glutathione which is needed to manage oxidative stress in the brain.
Birds upregulated glutathione synthesis by constitutive upregulation of Nrf2 and also avoided the problem of hyperkeratosis through downregulation of ARE binding by NRF2 at β-keratin loci. They have more glutathione, still have all their feathers, and no hyperkeratosis.
It is possible humans lost hair first, which freed up cysteine to be used for glutathione, which then allowed for encephalization.
#Birds #cysteine #evolution #flight #HumanEvolution #OxidativeStress #KEAP1 #Nrf2
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Flight & Brains, Feathers & Hair
June 03, 2020
Adaptation to flight has a big impact on antioxidant defenses; recently this paper came up in my feed:Adaptation of the master antioxidant response connects metabolism, lifespan and feather development pathways in birds [2020] - https://www.nature.com/articles/s41467-020-16129-4
“Birds (Aves) display high metabolic rates and oxygen consumption relative to mammals, increasing reactive oxygen species (ROS) formation. Although excess ROS reduces lifespan by causing extensive cellular dysfunction and damage, birds are remarkably long-lived. We address this paradox by identifying the constitutive activation of the NRF2 master antioxidant response in Neoaves (~95% of bird species), providing an adaptive mechanism capable of counterbalancing high ROS levels. We demonstrate that a KEAP1 mutation in the Neoavian ancestor disrupted the repression of NRF2 by KEAP1, leading to constitutive NRF2 activity and decreased oxidative stress in wild Neoaves tissues and cells. Our evidence suggests this ancient mutation induced a compensatory program in NRF2-target genes with functions beyond redox regulation—including feather development—while enabling significant metabolic rate increases that avoid trade-offs with lifespan. The strategy of NRF2 activation sought by intense clinical investigation therefore appears to have also unlocked a massively successful evolutionary trajectory.
The physiological risks of constitutive NRF2 activation due to loss of KEAP1 binding have been demonstrated in vivo through KEAP1 knockout mice, which die from starvation shortly after birth from hyperkeratosis of the gastrointestinal tract, likely through overexpression of α-keratins and loricrins in squamous cells (ref. 38; Fig. 4c). In addition to α-keratins, avian skin keratinocytes also express β-keratin genes, which combine with α-keratins to form avian skin appendages (feathers, scales, claws, beaks; ref. 3). ...
This strongly suggests that the NRF2-mediated regulation of β-keratins we detected in Chicken skin has been compensated for by the loss of AREs and downregulation of ARE binding by NRF2 at Neoaves β-keratin loci. This pattern closely mirrors the loss of NRF2-mediated ARE-regulation in Neoaves GSTA2 (Fig. 4b). Together these analyses provide in vivo evidence that the evolution of NRF2-associated feather development genes may have been shaped by the constitutive activation of NRF2 in Neoaves.”
This reminded me of some work on the evolution of large brain size in humans & loss of body hair:
Hair for brain trade-off, a metabolic bypass for encephalization [2014] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190188/
“Hair loss in humans is perplexing and raises many hypothetical explanations. This paper suggests that hair loss in humans is metabolically related to encephalization; and that hair covered hominids would have been unable to evolve large brains because of a dietary restriction of several amino acids which are essential for hair and brain development. We use simulations to imply that hair loss must have preceded increase in brain size & volume. In this respect we see hair loss as a major force in human evolution. We assume that hair reduction required favorable climatic conditions and must have been quick. Using evolutionary and ecological time scales, we pinpoint hair loss to a period around 2.2-2.4 million years ago. The dating is further supported by a rapid selection at that time of the sialic acid deletion mutation which may have protected growing human brains against calcium ion flux. In summary we view encephalization, in part, as a metabolic trade-off between hair and brain. Other biochemical changes may have intervened in the process too; and the deletion mutation of sialic acid hydroxylation may have been involved as well.
Human hair is composed of about 17% cysteine, a sulphuric amino acid noted for its ability to add rigidity to biological tissue (Table 3).”
Cysteine is also a major component of glutathione and a rate limiter for its synthesis; glutathione production is regulated through Nrf2. The Dror & Hopp 2014 paper mentions glutathione briefly; if the theory presented is correct, the increased need for glutathione synthesis is likely the major driver. In short, humans may have lost their body hair because of the increased demand for cysteine to produce glutathione which is needed to manage oxidative stress in the brain.
Birds upregulated glutathione synthesis by constitutive upregulation of Nrf2 and also avoided the problem of hyperkeratosis through downregulation of ARE binding by NRF2 at β-keratin loci. They have more glutathione, still have all their feathers, and no hyperkeratosis.
It is possible humans lost hair first, which freed up cysteine to be used for glutathione, which then allowed for encephalization.
#Birds #cysteine #evolution #flight #HumanEvolution #OxidativeStress #KEAP1 #Nrf2
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Flight & Brains, Feathers & Hair
June 03, 2020
Adaptation to flight has a big impact on antioxidant defenses; recently this paper came up in my feed:Adaptation of the master antioxidant response connects metabolism, lifespan and feather development pathways in birds [2020] - https://www.nature.com/articles/s41467-020-16129-4
“Birds (Aves) display high metabolic rates and oxygen consumption relative to mammals, increasing reactive oxygen species (ROS) formation. Although excess ROS reduces lifespan by causing extensive cellular dysfunction and damage, birds are remarkably long-lived. We address this paradox by identifying the constitutive activation of the NRF2 master antioxidant response in Neoaves (~95% of bird species), providing an adaptive mechanism capable of counterbalancing high ROS levels. We demonstrate that a KEAP1 mutation in the Neoavian ancestor disrupted the repression of NRF2 by KEAP1, leading to constitutive NRF2 activity and decreased oxidative stress in wild Neoaves tissues and cells. Our evidence suggests this ancient mutation induced a compensatory program in NRF2-target genes with functions beyond redox regulation—including feather development—while enabling significant metabolic rate increases that avoid trade-offs with lifespan. The strategy of NRF2 activation sought by intense clinical investigation therefore appears to have also unlocked a massively successful evolutionary trajectory.
The physiological risks of constitutive NRF2 activation due to loss of KEAP1 binding have been demonstrated in vivo through KEAP1 knockout mice, which die from starvation shortly after birth from hyperkeratosis of the gastrointestinal tract, likely through overexpression of α-keratins and loricrins in squamous cells (ref. 38; Fig. 4c). In addition to α-keratins, avian skin keratinocytes also express β-keratin genes, which combine with α-keratins to form avian skin appendages (feathers, scales, claws, beaks; ref. 3). ...
This strongly suggests that the NRF2-mediated regulation of β-keratins we detected in Chicken skin has been compensated for by the loss of AREs and downregulation of ARE binding by NRF2 at Neoaves β-keratin loci. This pattern closely mirrors the loss of NRF2-mediated ARE-regulation in Neoaves GSTA2 (Fig. 4b). Together these analyses provide in vivo evidence that the evolution of NRF2-associated feather development genes may have been shaped by the constitutive activation of NRF2 in Neoaves.”
This reminded me of some work on the evolution of large brain size in humans & loss of body hair:
Hair for brain trade-off, a metabolic bypass for encephalization [2014] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190188/
“Hair loss in humans is perplexing and raises many hypothetical explanations. This paper suggests that hair loss in humans is metabolically related to encephalization; and that hair covered hominids would have been unable to evolve large brains because of a dietary restriction of several amino acids which are essential for hair and brain development. We use simulations to imply that hair loss must have preceded increase in brain size & volume. In this respect we see hair loss as a major force in human evolution. We assume that hair reduction required favorable climatic conditions and must have been quick. Using evolutionary and ecological time scales, we pinpoint hair loss to a period around 2.2-2.4 million years ago. The dating is further supported by a rapid selection at that time of the sialic acid deletion mutation which may have protected growing human brains against calcium ion flux. In summary we view encephalization, in part, as a metabolic trade-off between hair and brain. Other biochemical changes may have intervened in the process too; and the deletion mutation of sialic acid hydroxylation may have been involved as well.
Human hair is composed of about 17% cysteine, a sulphuric amino acid noted for its ability to add rigidity to biological tissue (Table 3).”
Cysteine is also a major component of glutathione and a rate limiter for its synthesis; glutathione production is regulated through Nrf2. The Dror & Hopp 2014 paper mentions glutathione briefly; if the theory presented is correct, the increased need for glutathione synthesis is likely the major driver. In short, humans may have lost their body hair because of the increased demand for cysteine to produce glutathione which is needed to manage oxidative stress in the brain.
Birds upregulated glutathione synthesis by constitutive upregulation of Nrf2 and also avoided the problem of hyperkeratosis through downregulation of ARE binding by NRF2 at β-keratin loci. They have more glutathione, still have all their feathers, and no hyperkeratosis.
It is possible humans lost hair first, which freed up cysteine to be used for glutathione, which then allowed for encephalization.
#Birds #cysteine #evolution #flight #HumanEvolution #OxidativeStress #KEAP1 #Nrf2
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Flight & Brains, Feathers & Hair
June 03, 2020
Adaptation to flight has a big impact on antioxidant defenses; recently this paper came up in my feed:Adaptation of the master antioxidant response connects metabolism, lifespan and feather development pathways in birds [2020] - https://www.nature.com/articles/s41467-020-16129-4
“Birds (Aves) display high metabolic rates and oxygen consumption relative to mammals, increasing reactive oxygen species (ROS) formation. Although excess ROS reduces lifespan by causing extensive cellular dysfunction and damage, birds are remarkably long-lived. We address this paradox by identifying the constitutive activation of the NRF2 master antioxidant response in Neoaves (~95% of bird species), providing an adaptive mechanism capable of counterbalancing high ROS levels. We demonstrate that a KEAP1 mutation in the Neoavian ancestor disrupted the repression of NRF2 by KEAP1, leading to constitutive NRF2 activity and decreased oxidative stress in wild Neoaves tissues and cells. Our evidence suggests this ancient mutation induced a compensatory program in NRF2-target genes with functions beyond redox regulation—including feather development—while enabling significant metabolic rate increases that avoid trade-offs with lifespan. The strategy of NRF2 activation sought by intense clinical investigation therefore appears to have also unlocked a massively successful evolutionary trajectory.
The physiological risks of constitutive NRF2 activation due to loss of KEAP1 binding have been demonstrated in vivo through KEAP1 knockout mice, which die from starvation shortly after birth from hyperkeratosis of the gastrointestinal tract, likely through overexpression of α-keratins and loricrins in squamous cells (ref. 38; Fig. 4c). In addition to α-keratins, avian skin keratinocytes also express β-keratin genes, which combine with α-keratins to form avian skin appendages (feathers, scales, claws, beaks; ref. 3). ...
This strongly suggests that the NRF2-mediated regulation of β-keratins we detected in Chicken skin has been compensated for by the loss of AREs and downregulation of ARE binding by NRF2 at Neoaves β-keratin loci. This pattern closely mirrors the loss of NRF2-mediated ARE-regulation in Neoaves GSTA2 (Fig. 4b). Together these analyses provide in vivo evidence that the evolution of NRF2-associated feather development genes may have been shaped by the constitutive activation of NRF2 in Neoaves.”
This reminded me of some work on the evolution of large brain size in humans & loss of body hair:
Hair for brain trade-off, a metabolic bypass for encephalization [2014] - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4190188/
“Hair loss in humans is perplexing and raises many hypothetical explanations. This paper suggests that hair loss in humans is metabolically related to encephalization; and that hair covered hominids would have been unable to evolve large brains because of a dietary restriction of several amino acids which are essential for hair and brain development. We use simulations to imply that hair loss must have preceded increase in brain size & volume. In this respect we see hair loss as a major force in human evolution. We assume that hair reduction required favorable climatic conditions and must have been quick. Using evolutionary and ecological time scales, we pinpoint hair loss to a period around 2.2-2.4 million years ago. The dating is further supported by a rapid selection at that time of the sialic acid deletion mutation which may have protected growing human brains against calcium ion flux. In summary we view encephalization, in part, as a metabolic trade-off between hair and brain. Other biochemical changes may have intervened in the process too; and the deletion mutation of sialic acid hydroxylation may have been involved as well.
Human hair is composed of about 17% cysteine, a sulphuric amino acid noted for its ability to add rigidity to biological tissue (Table 3).”
Cysteine is also a major component of glutathione and a rate limiter for its synthesis; glutathione production is regulated through Nrf2. The Dror & Hopp 2014 paper mentions glutathione briefly; if the theory presented is correct, the increased need for glutathione synthesis is likely the major driver. In short, humans may have lost their body hair because of the increased demand for cysteine to produce glutathione which is needed to manage oxidative stress in the brain.
Birds upregulated glutathione synthesis by constitutive upregulation of Nrf2 and also avoided the problem of hyperkeratosis through downregulation of ARE binding by NRF2 at β-keratin loci. They have more glutathione, still have all their feathers, and no hyperkeratosis.
It is possible humans lost hair first, which freed up cysteine to be used for glutathione, which then allowed for encephalization.
#Birds #cysteine #evolution #flight #HumanEvolution #OxidativeStress #KEAP1 #Nrf2
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This is really interesting, especially that there a sex difference.
I'd like to write something about why, but am unable to do so at present.
Here's a old blog post I wrote on the topic of cysteine in birds and humans:
Flight & Brains, Feathers & Hair
June 03, 2020
https://rhyobrain.blogspot.com/2020/06/flight-brains-feathers-hair.html#cysteine #Nrf2 #HumanEvolution #Birds #glutathione #OxidativeStress
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This is really interesting, especially that there a sex difference.
I'd like to write something about why, but am unable to do so at present.
Here's a old blog post I wrote on the topic of cysteine in birds and humans:
Flight & Brains, Feathers & Hair
June 03, 2020
https://rhyobrain.blogspot.com/2020/06/flight-brains-feathers-hair.html#cysteine #Nrf2 #HumanEvolution #Birds #glutathione #OxidativeStress
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This is really interesting, especially that there a sex difference.
I'd like to write something about why, but am unable to do so at present.
Here's a old blog post I wrote on the topic of cysteine in birds and humans:
Flight & Brains, Feathers & Hair
June 03, 2020
https://rhyobrain.blogspot.com/2020/06/flight-brains-feathers-hair.html#cysteine #Nrf2 #HumanEvolution #Birds #glutathione #OxidativeStress
-
This is really interesting, especially that there a sex difference.
I'd like to write something about why, but am unable to do so at present.
Here's a old blog post I wrote on the topic of cysteine in birds and humans:
Flight & Brains, Feathers & Hair
June 03, 2020
https://rhyobrain.blogspot.com/2020/06/flight-brains-feathers-hair.html#cysteine #Nrf2 #HumanEvolution #Birds #glutathione #OxidativeStress
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New fossil evidence suggests that “Lucy” may not have been our direct human ancestor after all
For decades, the 3.2-million-year-old fossil called “Lucy” has been a centerpiece in stories about human origins. A member of the species Australopithecus afarensis, Lucy was long presented as the most plausible direct ancestor of later humans...
More information: https://archaeologymag.com/2025/12/lucy-may-not-have-been-our-direct-human-ancestor/
Follow us @archaeology
#archaeology #archeology #archaeologynews #Australopithecus #HumanEvolution #anthropology
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Ancient DNA from a Calabrian cave reveals a small Bronze Age mountain community shaped by tight kinship, selective mobility, and extreme consanguinity. A reminder that prehistory was complex, local, and deeply human. #Archaeogenetics #BronzeAge #HumanEvolution #Bioarchaeology https://www.anthropology.net/p/kinship-in-the-shadows-of-the-apennines
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Little Foot, the most complete australopith skeleton ever found, may belong to neither Australopithecus africanus nor A. prometheus. New research suggests a distinct species and a more tangled human family tree. #HumanEvolution #Paleoanthropology #Fossils #Australopithecus https://www.anthropology.net/p/little-foot-and-the-problem-of-naming
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Ancient foot fossil finally identified as an enigmatic hominin species that lived alongside Lucy in Ethiopia
Scientists have solved a mystery concerning an unusual 3.4 million-year-old foot fossil from Ethiopia: it indeed comes from Australopithecus deyiremeda, a close but distinct relative of Lucy and her species, Australopithecus afarensis...
More info: https://archaeologymag.com/2025/11/hominin-species-lived-alongside-lucy-in-ethiopia/
Follow @archaeology
#archaeology #archeology #archaeologynews #Australopithecus #humanevolution #anthropology
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26-Nov-2025
New research by ASU paleoanthropologists gives valuable insight into how two ancient human ancestors coexisted in the same area
They assign a #hominin foot #fossil from #Lucy’s time to a different species – with help from teeth -
RE: https://sciences.social/@primatology/115572642951558575
New long-term data from Ngogo chimpanzees show that lethal territorial gains led to major boosts in fertility and infant survival. The findings offer a rare, living model for how spatial competition and resource control may have shaped past hominin societies. #Anthropology #Primates #HumanEvolution #PNAS
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A uniquely preserved Neanderthal skull from Italy reveals that their famous noses were not shaped by cold adaptation after all. Altamura’s nasal cavity forces a rethink of how Neanderthals grew, breathed, and evolved. #Neanderthals #Paleoanthropology #HumanEvolution #PNAS https://www.anthropology.net/p/the-cave-that-reshaped-a-face-what
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Who counts as human? Throughout history, one all too common thread is that groups of people often do not believe that other groups of people are also #human. If we evolved apart so that we were different species, would we recognize our shared humanity? For this years #FediBookFair I’m offering free copies of my just released novel HUMAN to all #FediHumans . Just go to https://bretthodnett.com/FreeHUMAN.html and use the code ‘fedihuman’.
https://bretthodnett.com/HUMAN.html#BookLaunch #ScienceFiction #BooksOfMastodon #NewBook #Book #Books #Fiction #EPUB #Ebook #FreeBooks #GiveAway #SciFi #Evolution #SpeculativeFiction #HumanEvolution #WhatToRead #Readers #WritingCommunity #Fediverse #Human
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Humanity and AI: Evolving Conscious Responsibility https://visionleon.com/humanity-and-ai-evolving-conscious-responsibility/?utm_source=mastodon&utm_medium=social&utm_campaign=ReviveOldPost #Resilience #Philosophy #Consciousness #humanevolution #DLeonDantes #psychology #aiethics
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Ancient DNA reveals how the Sarmatians—steppe warriors who once challenged Rome—migrated, mixed, and quietly became part of Europe’s genetic legacy. Their story is one of disappearance through survival. #Archaeogenetics #HumanEvolution #AncientDNA #Sarmatians https://www.anthropology.net/p/the-vanished-riders-of-the-steppe
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A broken gene helped early farmers survive Neolithic plagues. The FUT2 mutation blocked norovirus but raised other risks—a tradeoff still shaping our health. #HumanEvolution #Archaeogenetics #AncientDNA #Microbes https://www.anthropology.net/p/the-mutation-that-shielded-early
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A 40,000-year-old East Asian genome reveals an early Homo sapiens lineage with almost no Denisovan ancestry—challenging ideas about contact, migration, and evolution across Ice Age Asia. #Archaeogenetics #HumanEvolution #Denisovans #Pleistocene @janetk.bsky.social https://www.anthropology.net/p/the-missing-denisovan-shadow
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9,000 years of skeletons show that bone aging is more than biology—it’s culture in motion. Holocene humans aged with the same skeletal rhythm despite changing lifestyles. #Anthropology #Archaeology #HumanEvolution #BoneHealth https://www.anthropology.net/p/when-bones-remember-movement-9000
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Ancient DNA shows the Slavic migrations reshaped Europe, replacing much of the local gene pool in regions like Poland & Germany. Entire families moved, blending with locals & forming new societies. #Archaeogenetics #HumanEvolution #Slavs https://www.anthropology.net/p/how-the-slavic-migrations-reshaped
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Mystery hominin skull discovered in 1960 dated to at least 286,000 years old
A mystery in human evolution may be close to being solved, thanks to a new study by the Institut de Paléontologie Humaine in France. A nearly complete cranium discovered in 1960 inside the Petralona Cave in northern Greece has defied all efforts at identification and precise dating for several decades...More info: https://archaeologymag.com/2025/08/petralona-skull-discovered-in-1960/
Follow @archaeology
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Chimpanzees choose stone tools like early human ancestors from 2.5 million years ago
A new study published in the Journal of Human Evolution has shown remarkable similarities between how modern chimpanzees and early human ancestors pick tools...
More information: https://archaeologymag.com/2025/01/chimpanzees-choose-stone-tools-like-human-ancestors/
Follow @archaeology
#archaeology #archeology #archaeologynews #anthropology #oldowan #hominin #humanevolution #chimpanzee #evolution
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17-Jan-2025
Three million years ago, our ancestors were #vegetarian
Nitrogen isotopes in tooth enamel show no evidence of meat consumption in #Australopithecushttps://www.eurekalert.org/news-releases/1070872 #science #humans #anthropology #HumanEvolution #evolution
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At least 2 hominin species lived at Laetoli site 3.6 million years ago - Enlarge / A human relative left these five tracks in a 3.6 million-year... - https://arstechnica.com/?p=1818035 #paleoanthropology #australopithecus #humanevolution #anthropology #a.afarensis #archaeology #itsnotbears #bipedalism #footprints #maryleakey #hominins #science #laetoli #lucy
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Long after some hominins were bipedal, others stuck to the trees - Enlarge / The excavation site where the bones were found. (credit: Georgiou et al. 2020)
We alrea... more: https://arstechnica.com/?p=1664227 #paleoanthropology #australopithecus #homininevolution #ancienthominins #humanancestors #humanevolution #archaeology #hominins #science #femurs -
Probability helps narrow down the search for human ancestors - Enlarge / According to Du and Alemseged, A. sediba is probably not our direct ancestor. (credit: Br... more: https://arstechnica.com/?p=1508121 #paleoanthropology #australopithecus #humanevolution #anthropology #archaeology #hominins #science #lucy