On scientific beliefs, Indigenous knowledge, and paternity.

On scientific beliefs, Indigenous knowledge, and paternity.

Recently my spouse & I reviewed Jennifer Raff’s Origin: A Genetic History of the Americas for the American Biology Teacher magazine (in brief: Raff’s book is lovely, you should read it! I’ll include a link to our review once it’s published!), which deftly balances twin goals of disseminating scientific findings and honoring traditional knowledge.

By the time European immigrants reached the Americas, many of the people living here told stories suggesting that their ancestors had always inhabited these lands. This is not literally true. We have very good evidence that all human species – including Homo sapiens, Homo neaderthalensis, and Homo denisovans among possible others – first lived in Africa. Their descendants then migrated around the globe over a period of a few hundred thousand years.

As best we know, no lasting population of humans reached the Americas until about twenty thousand years ago (by which time most human species had gone extinct – only Homo sapiens remained).

During the most recent ice age, a few thousand humans lived in an isolated, Texas-sized grassland called Beringia for perhaps a few thousand years. They were cut off from other humans to the west and an entire continent to the east by glacial ice sheets. By about twenty thousand years ago, though, some members of this group ventured south by boat and established new homes along the shoreline.

By about ten thousand years ago, and perhaps earlier, descendants of these travelers reached the southern tip of South America, the eastern seaboard of North America, and everywhere between. This spread was likely quite rapid (from the perspective of an evolutionary biologist) based on the diversity of local languages that had developed by the time Europeans arrived, about five hundred years ago.

So, by the time Europeans arrived, some groups of people had probably been living in place for nearly 10,000 years. This is not “always” from a scientific perspective, which judges our planet to be over 4,000,000,000 years old. But this is “always” when in conversation with an immigrant who believes the planet to be about 4,000 years old. Compared with Isaac Newton’s interpretation of Genesis, the First People had been living here long before God created Adam and Eve.

If “In the beginning …” marks the beginning of time, then, yes, their people had always lived here.

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I found myself reflecting on the balance between scientific & traditional knowledge while reading Gabriel Andrade’s essay, “How ‘Indigenous Ways of Knowing’ Works in Venezuela.” Andrade describes his interactions with students who hold the traditional belief in partible paternity: that semen is the stuff of life from which human babies are formed, and so every cis-man who ejaculates during penetrative sex with a pregnant person becomes a father to the child.

Such beliefs might have been common among ancient humans – from their behavior, it appears that contemporary chimpanzees might also hold similar beliefs – and were almost certainly widespread among the First Peoples of South America.

I appreciate partible paternity because, although this belief is often framed in misogynistic language – inaccurately grandiose claims about the role of semen in fetal development, often while ignoring the huge contribution of a pregnant person’s body – the belief makes the world better. People who are or might become pregnant are given more freedom. Other parents, typically men, are encouraged to help many children.

Replacing belief in partible paternity with a scientifically “correct” understanding of reproduction would probably make the world worse – people who might become pregnant would be permitted less freedom, and potential parents might cease to aid children whom they didn’t know to be their own genetic offspring.

Also, the traditional knowledge – belief in partible paternity – might be correct.

Obviously, there’s a question of relationships – what makes someone a parent? But I also mean something more biological — a human child actually can have three or more genetic contributors among their parents.

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Presumably you know the scientific version of human reproduction. To wit: a single sperm cell merges with a single egg cell. This egg rapidly changes to exclude all the other sperm cells surrounding it, then implants in the uterine lining. Over the next nine months, this pluripotent cell divides repeatedly to form the entire body of a child. The resulting child has exactly two parents. Every cell in the child’s body has the same 3 billion base pair long genome.

No scientist believes in this simplified version. For instance, every time a cell divides, the entire genome must be copied – each time, this process will create a few mistakes. By the time a human child is ready to be born, their cells will have divided so many times that the genome of a cell in the hand is different from the genome of a cell in the liver or in the brain.

In Unique, David Linden writes that:

Until recently, reading someone’s DNA required a goodly amount of it: you’d take a blood draw or a cheek swab and pool the DNA from many cells before loading it into the sequencing machine.

However, in recent years it has become possible to read the complete sequence of DNA, all three billion or so nucleotides, from individual cells, such as a single skin cell or neuron. With this technique in hand, Christopher Walsh and his coworkers at Boston Children’s Hopsital and Harvard Medical School isolated thirty-six individual neurons from three healthy postmortem human brains and then determined the complete genetic sequence for each of them.

This revealed that no two neurons had exactly the same DNA sequence. In fact, each neuron harbored, on average, about 1,500 single-nucleotide mutations. That’s 1,500 nucleotides out of a total of three billion in the entire genome – a very low rate, but those mutations can have important consequences. For example, one was in a gene that instructs the production of an ion channel protein that’s crucial for electrical signaling in neurons. If this mutation were present in a group of neurons, instead of just one, it could cause epilepsy.

No human has a genome: we are composite creatures.

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Most scientists do believe that all these unique individual genomes inside your cells were composed by combining genetic information from your two parents and then layering on novel mutations. But we don’t know how often this is false.

Pluripotent (“able to form many things”) cells from a developing human embryo / fetus / baby can travel throughout a pregnant person’s body. This is quite common – most people with XX chromosomes who have given birth to people with XY chromosomes will have cells with Y chromosomes in their brains. During the gestation of twins, the twins often swap cells (and therefore genomes).

At the time of birth, most humans aren’t twins, but many of us do start that way. There’s only a one in fifty chance of twin birth following a dizygotic pregnancy (the fertilization of two or more eggs cells released during a single ovulation). Usually what happens next is a merger or absorption of one set of these cells by another, resulting in a single child. When this occurs, different regions of a person’s body end up with distinct genetic lineages, but it’s difficult to identify. Before the advent of genetic sequencing, you might notice only if there was a difference in eye, skin, or hair color from one part of a person’s body to the next. Even now, you’ll only notice if you sequence full genomes from several regions of a person’s body and find that they’re distinct.

For a person to have more than two genetic contributors, there would have to be a dizygotic pregnancy in which sperm cells from unique individuals merged with the two eggs.

In the United States, where the dominant culture is such that people who are trying to get pregnant are exhorted not to mate with multiple individuals, studies conducted in the 1990s found that at least one set of every few hundred twins had separate fathers (termed “heteropaternal superfecundication”). In these cases, the children almost certainly had genomes derived from the genetic contributions of three separate people (although each individual cell in the children’s bodies would have a genome derived from only two genetic contributors).

So, we actually know that partible paternity is real. Because it’s so difficult to notice, our current estimates are probably lower bounds. If 1:400 were the rate among live twins, probably that many dizygotic pregnancies in the United States also result from three or more genetic contributors. Probably this frequency is higher in cultures that celebrate rather than castigate this practice.

Honestly, I could be persuaded that estimates ranging anywhere from 1:20 to 1:4,000 were reasonable for the frequency that individuals from these cultures have three or more genetic contributors.** We just don’t know.

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I agree with Gabriel Andrade that we’d like for medical students who grew up believing in partible paternity to benefit from our scientific understanding of genetics and inheritance – this scientific knowledge will help them help their patients. But I also believe that, even in this extreme case, the traditional knowledge should be respected. It’s not as inaccurate as we might reflexively believe!

The scientific uncertainty I’ve described above doesn’t quite match the traditional knowledge, though. A person can only receive genetic inheritance from, ahem, mating events that happen during ovulation, whereas partible paternity belief systems also treat everyone who has sex with the pregnant person over the next few months as a parent, too.

But there’s a big difference between contributing genes and being a parent. In Our Transgenic Future: Spider Goats, Genetic Modification, and the Will to Change Nature, Lisa Jean Moore discusses the many parents who have helped raise the three children she conceived through artificial insemination. Even after Moore’s romantic relationships with some of these people ended, they remained parents to her children. The parental bond, like all human relationships, is created by the relationship itself.

This should go without saying, but: foster families are families. Adopted families are families. Families are families.

Partible paternity is a belief that makes itself real.

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** A note on the math: Dizygotic fertilization appears to account for 1:10 human births, and in each of these cases there is probably at least some degree of chimerism in the resulting child. My upper estimate for the frequency that individuals have three or more genetic contributors, 1:20, would be if sperm from multiple individuals had exactly equal probabilities of fertilizing each of the two egg cells. My lower estimate of 1:4,000 would be if dizygotic fertilization from multiple individuals had the same odds as the 1:400 that fraternal twin pairs in the U.S. have distinct primary genetic contributors. Presumably a culture that actively pursues partible paternity would have a higher rate than this, but we don’t know for sure. And in any case, these are large numbers! Up to 5% of people from these cultures might actually have three or more genetic contributors, which is both biologically relevant and something that we’d be likely to overlook if we ignored the traditional Indigenous knowledge about partible paternity.

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header image from Zappy’s Technology Solution on flickr

On food and willing sacrifice.

On food and willing sacrifice.

Agni_devaIn ancient Indian mythology, fire was a god.  The word for fire is agni, and Agni the god who ate oblations.  Agni served as mouth and gullet for the entire pantheon – when sacrifices were offered to any god, Agni would eat them, ferrying goods from our world to the spirit realm.

When the gods were cursed such that they could not sire children with their wives, Agni, who’d once consumed Shiva’s semen, was asked to stray.  From Robert Goldman’s translation of Valmiki’s Ramayana:

(note, in terms of safety for reading at work, that the following passage is decidedly less circumspect than you might expect based on a familiarity with other sacred texts, e.g. the King James rendering of Genesis 38:9)

[A]ll the gods proceeded to Mount Kailasa, adorned with metallic ores, and charged Agni, the god of fire, with the task of begetting a son.  ‘You are a god, eater of oblations, and should carry out this task of the gods.  Great is your splendor.  You must release the semen into the Ganges, the daughter of the mountain.’

Agni, the purifier, promised the gods he would do this and so, approaching the Ganges, he said, ‘Bear this embryo, goddess, as a favor to the gods.’

Shantanu_Meets_Goddess_Ganga_by_Warivick_GobleHearing these words, she assumed her divine form, and he, seeing her extraordinary beauty, scattered the semen all over.  Agni, the purifier, showered it all over the goddess, so that all the channels of the Ganges were filled with it. 

In ancient Indian mythology, the semen of powerful males will sprout children wherever it lands, no female gamete required.  Numerous heroes were engendered when males chanced across beautiful women bathing and shortly thereafter just happened to ejaculate – their children might be born from baskets, butter jars, or someone’s mouth.

A fetus soon formed from the material sprinkled over Ganges’s body, but although she’d consented willingly to bear the child, she soon declared it to be too powerful, that the embryo was burning her body.  She tucked it into the base of the Himalayas to finish gestation.

Later in the Ramayana, Sita attempts to sacrifice herself – but Agni will not take her.  Sita was kidnapped and so her husband Rama comes to rescue her.  With the help of a monkey army, Rama destroys a South Indian kingdom and slays his wife’s captor.  But he assumes that Sita has been tarnished by rape.  He tells her (in the Robert Goldman and Sally Sutherland Goldman translation):

I have recovered my reputation, and that is the purpose for which I won you back.  I do not love you anymore.  Go hence wherever you like.”

Heartbroken, Sita decides to jump into a fire – she’d rather die than lose her husband.  But the fire doesn’t burn her.  Instead, her presence is said to burn the fire itself.  Agni lifts her from the bonfire and tells her husband that she is beyond reproach.  The man agrees, briefly, to take her back.

Agni_pariksha

More often, Agni simply burns things.  Objects from our world disappear, leaving nothing but ash.

And we are also like fire.   In David Shulman’s essay for the New York Review of Books, he writes:

Fire_from_brazierFor Vedic thinkers, all that lives survives by consuming other living beings.  Humans, too, have a hungry fire burning in their bellies; they have to sacrifice other creatures to that fire every day if they are going to stay alive.

We are heterotrophs.  Unlike plants, we can’t create ourselves by drinking in water, air, and sunlight.  We have to eat – sacrificing something – to survive.

Much of the time, the sacrifices that allow our lives are violent.  Humans evolved as meat eaters – scavengers, likely, then hunters.  We stalked, killed, and butchered mammoths.  On contemporary industrial farms, plants are culled by nightmarish threshers, ripped from the ground and shaken clean by machines.

We are heterotrophs.  It’s either us or them.

But sometimes we’re fueled by willing sacrifice.

apple-1122537_1280Fruit-bearing plants co-evolved with animals.  Fruit is a gift.  When a plant bears fruit, it hopes for reciprocity, but in a generalized way.  The plant isn’t trading – it can’t guarantee that any one offering will procure a service.  But over time, many hungry animals have willingly spread the plants’ seeds – that’s the gift we offer in return.

(This is true of all fruit.  I’d say it’s foolish to trust our Supreme Court justices’ opinions on just about anything – I definitely wouldn’t expect them to correctly identify the parts of a plant.  In addition to bananas, grapes, and apples, things like tomatoes, squash, zucchini, and peppers are fruit.  It’s thought that each type of fruit co-evolved with a specific animal that was originally responsible for spreading its seeds.)

Even if a plant gives fruit to us willingly, though, you could wonder whether the fruit agrees with the sacrifice.  No matter what the tree might want, perhaps an apple would rather not be eaten.

Any one cell might prefer not to die.

1024px-Mucinous_lmp_ovarian_tumour_intermed_magCancer is a rough equivalent to libertarian philosophy.  Cancer is the ultimate freedom.  In a multicellular organism, most individual cells will voluntarily cease to grow when their industry infringes upon their neighbors.  They experience “contact inhibition.”  As soon as a cell touches another, it respects the established boundaries as inviolable.

If a cell’s usefulness has waned, it undergoes apoptosis – voluntary suicide.

In a multicellular organism that practices sexual reproduction – even unilateral reproduction like Agni showering sperm over Ganges’s prostrate body – every cell that isn’t part of the germ line is doomed to die.  From the perspective of evolution, your body is like a disposable rocket ship, built only to ferry the lineage of cells in your genitalia forward through time.  Those cells matter – their descendants might survive forever.

The cells in your hand?  They might have children, and grandchildren, and great-grandchildren – but their line will come to an abrupt end.  Maybe you were bitten by a radioactive super-power-granting DNA-altering spider and the cells in your hand became amazing.  Doesn’t matter.  Their glorious kind will go extinct.

And if the cells in your hand decide that this isn’t fair, and instead liberate themselves from the shackles of self-restraint and suicide, growing as much as possible – well, that’s cancer.  The host organism will die.  And those renegade cells, the ones who adopted the mantra look out for number one, will inevitably also die, starving fruitlessly, progeny-less.

It’s the same old tragedy of the commons, the same reason why there are now so few fish in the sea, and why Easter Island has no trees.  Sometimes personal persistence dooms you more completely than would sacrifice toward a common cause.

On Edward Dolnick’s ‘The Seeds of Life’ and artificial wombs.

On Edward Dolnick’s ‘The Seeds of Life’ and artificial wombs.

Juvenile_Smooth_Guarding_Frog_(Limnonectes_palavanensis)_maybe-_(6967250574)Among the smooth guardian frogs of Borneo, females croon to the males, attempting to woo a mate.  This is abnormal for frogs: usually females are serenaded.  But males of this species are the most devoted parents – they guard the fertilized eggs and carry tadpoles from pond to pond after they hatch.  Whereas the females simply lay eggs and leave.

Because male smooth guardian frogs contribute most to the next generation, they are more discerning than females when choosing a mate.  Unclaimed males might be surrounded by strident singers, each striving to win his affection.

Do smooth guardian frogs tell myths?  If their myths are anything like ours, they probably exalt female creator gods whose eggs – sans any contribution from the males – burst forth with heroes.  Or even entire worlds.

Human myths purposefully invert the workings of the world.

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Among humans, females contribute most to survival of the species.  Females undergo nine months of gestation and perhaps years of breastfeeding for every child.  From the first, they pour huge amounts of energy into their offspring.

But human males – especially after the switch to agrarian lifestyles, at which point our minor sexual dimorphism made a large difference in how many calories each individual could procure – fancied themselves to be more important than females.  So we told stories in which men were the stewards of existence.

From Edward Dolnick’s The Seeds of Life:

9780465082957In ancient Egypt, the creation of new life – indeed, the creation of the entire universe – was emphatically the province of males.  Females played a subsidiary role or (in the case of the gods) no role at all.  Creation myths told of male gods who, as one historian writes, “gave birth to their spouses, their children, other humans, animals, cities, sanctuaries, shrines, perpetual offerings, earth, and the planets themselves.”

One papyrus manuscript records the boasts of the Sun God, who first created himself out of nothing – we are not told how – and then took matters into his own capable hands, masturbating the universe into existence.  “I created on my own every being … my fist became my spouse.  I copulated with my hand.”

In human myths from around the world, male gods act as solitary progenitors.  Yahweh creates the world alone.  Then Adam gives birth: a rib is taken from his body to make Eve.

The male leader of the Greek pantheon births a child: Athena springs forth from Zeus’s head.  In some variants of the Ramayana, Ravana creates Sita with a sneeze.

(Did the originator of this myth know anything about reproduction?  How could you imagine birthing a child through a nostril?)

Even among mortals, human males often imagined themselves to be the more important parents.  Obviously female bodies could carry new life, and male bodies could not.  So the men created myths in which female bodies were replaceable – in their telling, sperm was essential.  Women were not.

From Wendy Doniger’s Women, Androgynes, and Other Mythical Beasts:

51W-viAy4OL._SX331_BO1,204,203,200_In Hindu mythology the instances of unilateral female creation are by far outnumbered by unilateral male creation.  The male seed is fertile in itself, particularly the seed of a great ascetic who has kept it within him for a long time and is therefore “one whose seed is never shed in vain” (amogharetas); that is, he engenders a child every time he sheds his seed, no matter where he sheds it.  Even an ordinary man’s seed is basically the source of life, as is evident from the Upanisadic tradition; in Dharmasastra, too, the seed remains more important than the womb.  The seed shed by a powerful male may fall into any of a number of womb substitutes (a pot, the earth, a river, or somebody’s mouth) and produce an embryo.

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In The Seeds of Life, Dolnick describes the experiments that finally led Europeans to understand that both parents produce essential gametes.  In the late 1700s, Lazzaro Spallanzani sewed silk pants for male frogs as a form of full-body contraceptive device.  When frogs ejaculated inside their sperm-retaining pants, eggs would not become embryos.  After the pants were turned inside out and rubbed across the jellied clumps of eggs, tadpoles grew.

Spallanzani also performed the first artificial insemination of a dog.  He was a Catholic priest.  Priesthood was different in those days.

rogersShortly after I finished reading The Seeds of Life, we discussed Pattiann Rogers’s “The Rites of Passage” in jail.  This poem opens with the initial cleavage of a fertilized frog egg, followed by its development into a blastula and the formation of organs until

that one definite moment

When a fold of cells quivers suddenly for the first time

And someone says loudly “heart,” born, beating steadily,

Bearing now in the white water of the moon

The instantaneous distinction of being liable to death.

We talked about the almost magical border between nothingness and life – J. said, “When I had my son, I didn’t even want to tell anybody for months, I was worried they’d laugh, they’d say, like, you, you’re just gonna fuck it up.”  And S. said, “I dunno, man, my kid was born, and I was just like, damn.  I made that!”

The thing that hurts these men most is that they’re not there for their kids.

Then we talked about embryology.  I told the men, briefly, about Spallanzani’s experiments.  Then told them that, although I’ve never touched the genitalia of any non-human animal, I used to work next to a man who collected sperm from horseshoe crabs.  He wore gloves.  The supine crabs scrabbled for his arm with their little claws.

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Although early European doctors thought human females contributed nothing to a child other than a fertile field for growth, they were concerned that feminine misbehavior could corrupt poison the filed and corrupt a fetus.  From Rebecca Kukla’s Mass Hysteria:

419Nh3Un2WL._SX331_BO1,204,203,200_The seventeenth-century textbooks are particularly concerned about and often organized around the possibility of deformed births, with a special focus on the dangers of the impure, permeated womb.  Sadler’s book, for instance, is organized primarily as a list of ways in which the womb can fail to maintain its purity and its integrity–the womb here leaks and ‘weeps,’ and various ‘corrupt humours’ flow in and out of it, making nothing more ‘perilous’ to the body than the ‘ill-affected womb.’ 

Many of the works go into elaborate detail, describing and often visually representing famous cases of monstrous births.  Monstrous births could be the product of weak seed or impure blood, of conception during menstruation, of the woman fertilizing herself with her own seed (!), or, most importantly and consistently, of maternal ingestions of sights and substances that could pollute or deform the womb.  In justifying the need for careful knowledge and monitoring of the maternal body, in the preface of his book, Sadler warns us: “From the womb come convulsions, epilepsies, apoplexies, palseys, hecticke fevers, dropsies, malignant ulcers, and to bee short, there is no disease so ill but may proceed from the evil quality of it.”

They thought that if a pregnant female gazed upon an impure sight, or had an impure thought, the child inside her would be irrevocably damaged.  Which implied the converse.  If a baby was born wrong – mentally or physically disabled – it was proof that the mother’s mind was foul.  Kukla reports that “lascivious thoughts could produce hermaphrodism and other obscene monstrosities.

Children needed to be protected from their mothers.  Otherwise women’s lascivious thoughts would cause a decline in the human race.

For years, doctors recommended that women not breastfeed their children – mothers could exert a harmful influence through their milk as well.  A mother who was good and pure would produce healthful milk, they thought, but most were not.  After all, sex itself was sin.  And children were rarely engendered without sex.  To minimize risk, mothers should feed their babies with commercially prepared substitutes instead.

These doctors would have been thrilled to read in the news, as I did the other day, that modern researchers have come closer to developing an artificial womb.  Children can be kept safe from the perfidies of maternal imagination!  And though it’s not quite unilateral male creation, this “fluid-filled biobag” is akin to the womb-replacing baskets and jars of ghee of Hindu myth.

lamb

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And yet.  A belief that men convey the stuff of life, with women serving solely as a fertile patch of earth, need not lead to misogynistic behavior.  Some cultures have used the same mistaken mythologies to create more egalitarian worlds.

Again from Dolnick’s The Seeds of Life:

Common across many cultures, too, even today, is a belief that it takes many acts of sex to create a baby.  “Many of my New Guinea friends feel obliged to have regular sex right up to the end of pregnancy,” writes the scientist Jared Diamond, “because they believe that repeated infusions of semen furnish the material to build the fetus’s body.”

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Many South American tribes go a step further: not only is the developing baby built up from new batches of semen, but it is best if several different men make a contribution.  All those men are considered the child’s father.  Among the Bari people in Venezuela, for instance, “a good mother will make a point of having sex with several different men, especially when she is pregnant,” one historian writes, “so that her child will enjoy the qualities (and paternal care) not merely of the best hunter, but also of the best storyteller, the strongest warrior, and the most considerate lover.”

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Biology isn’t destiny.  Not even our beliefs about mythology force us to behave any particular way.  A world that is good and fair would be compatible with many myths.

 

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post-script: Shortly after this essay went up, the O.E.D. online’s “word of the day” was “murk,” which includes a misogynistic quote from the early 1400s that fits these themes perfectly.

From Prick of Conscience (1425): Man … was consyved synfully With-in his awen moder body … Par duellid man in a myrk dungeon And in a foul sted of corupcion.

As best I can tell, this would be rendered in modern English as “Man was conceived sinfully within his own mother’s body, and then he dwelled in a murky dungeon (her womb) in a foul state of corruption.”

Male writers have long seemed to channel their jealousy at women’s ability to create life into a hatred of women.  If men have no wombs, we’ll call wombs corrupt!  Although, did you look at that picture of the womb-replacing “bio-bag”?  Less murky, sure.  Totally exposed to the light.  But it also looks nightmarish.