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The Adoption Paradox

Raising someone else's child seems to make no sense from an evolutionary standpoint. So why is everyone doing it?

By Evan Eisenberg
Jan 1, 2001 6:00 AMJul 13, 2023 2:59 PM


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Perched on my computer as I pretend to write is a snapshot of my grandfather at 87, perched at the edge of his florid, Floridian marital bed. Standing on the bed, buck naked but for a diaper and a handbag, is not my grandmother— God save us— but my daughter at age 11/2. We have brought her south to amuse and comfort Harry as he battles prostate cancer.

Although there is no photo of Charles Darwin on my desk, I imagine him gazing down from somewhere and with befuddlement on this first photo. For my grandfather, like me, is plainly Caucasian, while my daughter is exquisitely Chinese.

Why, Darwin might wonder, is this old man, contemplating at point-blank range his own extinction, comforted by the knowledge that his only grandson's only child is not of his own blood but adopted— a cuckoo in the nest?

From a Darwinian standpoint, going childless by choice is hard enough to explain, but adoption, as the arch-Darwinist Richard Dawkins notes, is a double whammy. Not only do you reduce, or at least fail to increase, your own reproductive success, but you improve someone else's. Since the birth parent is your rival in the great genetic steeplechase, a gene that encourages adoption should be knocked out of the running in fairly short order.

It hasn't been.

Infertility, the usual premise of adoption, is no longer a rare and shameful condition but a fairly common lot of baby boomers who delay having babies until their careers are full-grown. Divorce and remarriage have shuffled and reshuffled households, leading new spouses to adopt each other's broods. And interracial and international adoptions are increasingly common. All told, 4 percent of Americans are adopted. That is only an estimate— official figures do not exist— but it gives satisfying numerical form to a feeling many of us have had lately: that adoption is coming out of the closet.

Of course, Americans at the turn of the millennium do all sorts of strange things. We have strayed so far from the "ancestral environment," as the evolutionary psychologists say, that one has to poke through layers of cultural and technological debris to find the logic of the genes. But a survey of human time and space finds many other cultures in which adoption has been common. In some of them, it has been far more common than it is with us. And extending the survey to the rest of the animal kingdom finds adoption, or something like it, practiced by an astonishing array of creatures, from orangutans to hermaphroditic worms.

For me, the fact that most confounds evolutionary psychology is to be found not in Rangiroa or the Serengeti but in my heart. It is the deep happiness I feel whenever I see, hear, touch, or think about my daughter, which is a good deal of my waking life. Perhaps my emotional range is limited, but I can't imagine loving my "own" child more. Nor am I odd in this regard. Studies show that adoptive parents are, on average, as happy as genetic parents, perhaps even a little happier. Their failure to fulfill the most basic biological imperative, far from turning them into freaks, seems to leave them slightly less prone to mental illness than most parents.

This is not a fact that Darwinism, in any of its forms, would have predicted. Trying to make sense of it requires a twofold motion: outward to the plains of data on other peoples and other species, inward to the tangled bank of memory.

I found freda in the recovery room, lifted her left hand and slipped on the ring, a whorled ivory tchotchke from a store on Fifth Avenue that had been going out of business for 20 years. It was an offer she was too groggy to refuse. She had not yet seen the surgeon, not yet been told that she had cancer and that her ovaries and uterus had been removed.

"You're okay," I told her. "Everything is okay." Later, when her fingers swelled up from the IV, it looked for a moment as if the ring might have to be cut off.

Preparing for the wedding, we had no time to grieve. Freda assumed that, when the time came, we would catch an orphan thrown up by the latest international crisis. As for me, I assumed nothing.

My parents mentioned something about surrogacy— hiring a woman to bear my child. Too brave and new for my world, probably, yet it offered the appeal of old-fashioned genetic paternity. As expected, Freda found the notion abhorrent even in its turkey-baster form. So we put the matter off— easy enough, as we were still relatively young, relatively poor, and blessed with relatives whose kids we could dandle on demand.

Suddenly (or so it felt), in the 12th year of our marriage, Freda handed down an ultimatum. If I wanted kids, it was time to get moving. If I didn't, it was time to let her know so she could come to terms with her childless life— now redefined, in mediaspeak, as "child free."

I came back from the library the next day with a cribful of books about surrogacy and adoption. Absorbed over the next few days, they did little to lighten the burden of decision. What did lighten the burden— what made it, on the instant, drop away— was the annual conference of the Open Door Society.

Here, instead of hapless couples salving the wound of infertility with the semblance of a family, I found thousands of happy families, normal in every way but two: They seemed happier than most, and more polychrome. In workshop after workshop I heard parents attest, with wonder still fresh, that their adopted child seemed meant for them from the start, and that they could not imagine loving a "biological" child more. And when, at the workshop on adopting from China, I saw a half dozen dark-eyed infants and toddlers sporting on their parents' knees, I felt a silken cord binding itself to my heart.

Motives for adopting may be as various as the people and animals that adopt. Among mammals, adoption has been reported in mice and rats, otters and skunks, llamas, deer and caribou, kangaroos and wallabies, seals and sea lions, as well as domestic animals such as dogs, pigs, goats, and sheep. Primates seem especially prone to adopt, as do carnivores of all sorts. A study of the largest terrestrial meat eater, the Alaskan brown bear, found foreign cubs in three of 104 litters, a percentage in the same ballpark as among North American humans.

The habit can be expensive. If the adoptee is added to an existing litter, the adopter's own offspring may get less to eat. If adopting delays the next brood, the adopter's lifetime reproductive success may be reduced. Even for the infertile, adoption seems maladaptive: It siphons off resources that might otherwise be shared with close relatives who share some fraction of their genes, thus reducing their "inclusive fitness."

As evolutionists are quick to point out, the logic of kinship cuts both ways: Animals often adopt their own relatives. Indeed, one locus classicus of adoption among mammals is a small, closely related band that hunts or forages cooperatively in a harsh or dicey environment. Here adoption is just the far end of a range of "alloparenting" behaviors that may include fostering, baby-sitting, cr?ching (a sort of day-care arrangement), and communal feeding. In a pride of lions, births are often synchronized, and any cub can get milk on demand from any lioness who has some; in a lean season, this pooling of resources will keep some cubs from starving. In a wolf pack, only one or two females give birth each year, but the whole pack helps raise the litter. Adults returning from the hunt with full bellies promptly discharge them to feed both the pups and their caretakers.

As biologists apply new genetic tools to the study of adoption, kinship does not provide the catchall answer that many thought it would. A female harbor seal, for example, who loses track of her pup on her crowded breeding ground will often adopt a foreign pup, whether motherless or not. Though these seals seem unable to tell kin from nonkin, scientists guessed that a female would tend to breed on the same stretch of beach where she had been bred; the resulting clustering of kin would mean that a female who adopted a nearby pup was likely to be adopting a relative, perhaps increasing her inclusive fitness. But DNA analysis of a colony on Sable Island in Canada shot down both those suppositions.

For some species, the main benefit of adoption may be that it allows for larger groups— and thus higher status and better access to resources. Among wild dogs, for instance, bigger packs are better at defending kills from spotted hyenas and at competing with other packs for prime hunting grounds. An extra pup can be an extra watch against lions. In more cynical terms, the chance that it will get picked off by a lion improves the odds for everyone else in the pack. The same principle applies to a variety of birds and mammals, including humans in farming societies, where the value of two extra hands generally outweighs the cost of an extra mouth.

When all else fails, Darwinians can chalk adoption up to reproductive error— the failure of parents to distinguish their own offspring from someone else's. The pandemonium of an elephant seal breeding ground, for instance, with hundreds of creatures the size of small trucks bellowing for their pups, is guaranteed to cause some mix-ups, even though the cost to the mothers can be great. Some end up trying to raise two pups, a feat that verges on the physically impossible.

Of course, the idea of reproductive error doesn't help much with cases of adoption by a nonbreeding female. If you have no infant of your own, you can hardly be accused of confusing it with someone else's.

The first time I see my daughter's face, it is on a computer screen. A click on the file e-mailed by our agency, and the face unrolls like a scroll. Starting from the top, with a vertical tuft of hair like a radio tower, an awesome visage materializes: massive forehead, arched eyebrows, small but penetrative eyes. Larger than life, they fill the screen. Summoning all my courage, I scroll down to expose the big Buddhist ears, the blithe Taoist nose, the Rosicrucian— no, rosebud— mouth, the neatly scalloped chin.

At sea in this vast facial landscape, at a loss to add up the parts and gauge the net effect, I maneuver the middle half of her face into the frame— and am met with a look of cold command, worthy of an empress dowager.

Command, intelligence, seriousness of purpose, even wisdom— admirable traits all, but not ones we look for in a baby. Will her zany father's antics leave her cold, not to say disdainful? Will she be cuddlable, ticklable, roughhousable, or will she require bearers and a litter?

The beginnings of an answer come three weeks later at the Lake View Garden Hotel, Wuhan, Hubei Province. As advertised, the hotel sits on a passably scenic lake, complete with a teahouse in the shape of a dragon boat. The lobby has red lacquer walls and fulsome carvings in ivory and jade. The conference room in which we stand is Western, with a long oval table in walnut veneer. But all these things have ceased to exist, for this is the instant of birth.

We are seeing our child— all of her— for the first time.

Or rather, we think we are seeing our child. Of the nine infants that have just swum into view, cradled by their Chinese "aunties" and swaddled within an inch of their lives, we have picked out the prettiest and most delicate— already a little girl— as the closest match to the photo we were sent of our "assignment." As the names are called out, we are shocked to see her handed to one of the single mothers in our group. And shocked again to be handed, when our names are called, a blob.

Not exactly: but a creature unformed, its sex indeterminate were it not already known, its mouth hanging open, breathing fishily. Like the others, it has a red dot on its forehead, as on a doll marked down for quick sale. Like the others, it is slightly shopworn: bronchia thick with mucus, back flogged with ringworm. Batteries, it seems, are not included, since this doll neither babbles nor smiles.

Four days later, we are in love.

It is not just that she has passed, red flags flying, the examination by the doctor our group brought along. Not just the alertness she shows when her eyes fly from speaker to speaker, like an umpire's at Wimbledon; nor yet the jackass strength of her legs when we try to change her diaper. Not, even, the bliss of that moment when her rosebud mouth— the one distinctly feminine feature in her mug shot— abruptly blooms in a smile.

So: What is it that makes us feel she is the child the gods have destined for us, as if we'd coupled on the carpet of heaven?

The traits that make humans ideal adoptive parents are the same ones that make us human: our big brains and our upright posture. These two hallmarks of our species have been at odds from the start, with more and more infant gray matter needing to squeeze through the straitened pelvis of the two-legged female. One solution was to let the brain, and the rest of the body, do much of its developing after birth, in the course of that lengthy (by animal standards) period of near-helplessness known as childhood. This in turn required of parents a nurturing instinct of uncommon strength and durability— an instinct that, if it could not find an outlet in one's own offspring, might well seize on someone else's.

But even this brain-in-a-nutshell is too big for the human birth canal, and vast numbers of infants and mothers (vast, again, by animal standards) have died as a result. Selection, therefore, has been against instant bonding between women and their babies. If women bonded with their infants during pregnancy or at birth, they might grieve for months or years for an infant that had died within minutes; they might thereby delay their next pregnancy and lower their lifetime reproductive success. Instead, women become attached to their babies gradually, over the course of months. Which means they can become attached to someone else's baby, too, if it's left in their lap long enough. By the same token, human babies run a high risk of entering the world at the same moment their mother leaves it. Hence, they are selected to be so adorable— or squall so pitiably— that some other mother will take them in.

Among Americans, adoption has been on the rise since the 1950s, when baby-boom hoopla made thousands of childless couples desperate to acquire a child from any source at any price. But that trend will have to continue for a long time before we come anywhere near the situation in Oceania. On Bellona, in the Solomon Islands, researchers found that 27 percent of the population was adopted. In Maat, in Vanuatu, the reported figure is 31 percent; on Kapingamarangi, in the Caroline Islands, it is 52 percent.

Adoption happens in various ways: An unmarried girl exports the product of love play; a warrior takes in the child of his vanquished foe; a couple short of children asks for one of a couple that seems well stocked. Anthropologists explain it in various ways. For Raymond Firth, the point of adoption among the Tikopia is that it does not "allow the bonds of the individual family to become so strong as to threaten the wider harmony." For Robert Levy, adoption in Tahiti sends the message that "relationships are contingent and interchangeable, and must not be taken too seriously." Others cite the survival value of redistributing wealth by redistributing mouths, still others the desire to have somebody to care for us in old age.

Readings in terms of natural selection are trickier. Anthropologist Joan Silk, in a statistical analysis of the data— first from Oceania, then from the Arctic and West Africa, two other hotbeds of fosterage and adoption— found that adopters and adoptees tended to be blood-related more closely than chance alone would predict. But since adoption of nonrelatives does occur in these and many other societies, inclusive fitness offers at best a partial answer.

In the West, too, adoption was once more commonplace than it is today. In Greece and Rome (as in China and India), a man who had produced no male heir would adopt one— often an adult— so that the family's cult and wealth might live on. (The emperor Octavian, to take one august example, was Julius Caesar's adopted son.) Here Darwinian logic was stood on its head, with descendants acquired to serve property rather than the other way around. The practice of "exposing" unwanted babies may have been, as the tale of Oedipus suggests, not so much a nasty form of infanticide as a way of putting children up for informal adoption. It took centuries of sermonizing, first by the church fathers, then by the Catholic and Protestant reformers, to convince people that adoption was a perversion of the order of nature, one that might encourage such further perversions as adultery (whose spawn could be legitimized by adoption) and incest (between close relatives who do not know they are relatives— see Oedipus).

If something in human nature makes us prone to adopt, it may be something we share with other primates. Spider monkeys, tarsiers, baboons, gibbons, chimpanzees, and orangutans have been caught in the act, and most other primates engage in alloparental care of one kind or another. As among humans, babies are fussed over. In some species, mothers with one infant will take in another, despite the considerable strain involved in feeding, carrying, and protecting both. Juveniles, nonbreeding adults, and mothers who have lost their own infants will sometimes be so keen to nurture that, if an orphan is not available, they will resort to kidnapping— which, if the birth mother is of lower rank or for some other reason fails to put up much of a fight, can lead to permanent adoption.

Sometimes adopter and adoptee are related, sometimes not. But there are other ways in which adoption may be adaptive. Among male macaques, an infant may serve as an "agonistic buffer," a living shield that wards off attack by other males, or as a passport to the troop's central male clique, upon acceptance to which the brat is discarded. A young adult male hamadryas baboon may adopt a juvenile female, sometimes against her mother's will; when she reaches puberty, she will become the first member of his harem. In any case, adoption among primates can't be chalked up to "reproductive error"— not in any literal sense. Like human adopters, these apes and monkeys seem to know what they are doing.

When the ethnographic files have been ransacked and the animal taxa accounted for, the hardest kind of adoption to explain in standard evolutionary terms may be the human, Western, modern kind— the kind my wife and I have committed.

Finding a mate, warding off aggression, getting better access to resources— these may be true Darwinian explanations of adoption in some animal species, but in Homo sapiens they are more likely to be acting, if at all, on the level of learned behavior. And indeed it isn't hard to see how adoption might be encouraged by a given culture, or spread through a population as a learned behavior, or "meme." Nor is it hard to see how adoption might be favored by "group selection"— to put it crudely, survival of the fittest populations, not just of the fittest individuals within populations. That form of Darwinism, which Darwin himself invoked to explain various kinds of altruism, became taboo in the 1960s but is now making a comeback, refined to meet logical and mathematical objections.

But for the kind of Darwinism that rules the new field of evolutionary psychology, as well as the popular press— the kind that delights in finding the bony grimace of selfishness beneath the fleshy lips of goodness— only one theory of modern adoption is of much use: namely, that the urge to nurture has been selected for because it is, in general, hugely adaptive; and that, in the world of early humans, the likelihood that someone would squander this urge on a nonrelated child was so remote that natural selection didn't bother taking measures against it. One biologist compares this to the human love of salt, an instinct healthy on the African savanna but less so in a 7-Eleven.

No father likes to think of his daughter (however addictive) in the same way as junk food, so naturally I'm inclined to poke holes in this theory. For instance, why shouldn't a strategy of reproductive parasitism— of leaving your infants at the door of an unrelated family's cave— have arisen among early humans? In that case, an instinct for rejecting all unrelated infants should have evolved too. And even if a frustrated parenting urge explains our behavior, what about that of my relatives, who have already had their quota of children? Why have my grandparents not only lavished as much great- grandparental investment on this alien dumpling as on their genetic descendants but also bragged about her even more? How can it be that the whole family— uncles, aunts, cousins— far from begrudging her a place in the nest, have made her their darling, dropping their sleekest worms into her heart-shaped mouth?

I don't know the answer. Maybe the parenting urge doesn't have to be dammed to rise above its biological bed. After all, people who already have genetic children adopt too. Or maybe something else is going on here, something evolutionary psychology cannot yet explain.

Once we become an adoptive family, our relationship to other infertile couples changes: We are a resource, a parable, a possible world. Some, braced by our example, also decide to adopt from China. What baffles us is that they don't all decide this the instant they meet our Sara Xing.

Most baffling are the couples who subject themselves to repeated, grueling rounds of fertility treatments before thinking seriously about adoption. Our bafflement is easily explained, of course: Unlike most infertile couples, Freda and I began with the knowledge that— as a couple— we would always be infertile. We were spared the anguish of the high-tech roller coaster on which hopes are monthly raised and monthly dashed.

Once we had adopted, it was easy to forget how the prospect of taking my genes to the grave had unsettled me. If the latex-gloved hand of modern medicine had reached out to us, wouldn't we have clutched it? Which brings us to the oldest of biological questions, that of the chicken and the egg. Is modern medicine responding to a natural, Darwinian demand? Or is it drumming up business, aided by the drug companies' ostinato and our culture's insistence that adoption is unnatural— a fatherhood of last resort, a motherhood of necessity?

The tendency of pop Darwinism— which, in one form or another, has been shaping American culture for well over a century— is to look at what we want, explain it in terms of what our genes want, and then suggest that what our genes want is what we really want. Our genes' hidden agenda— namely, their own proliferation in human bodies, from here to eternity— is supposed to be our agenda. If it is fulfilled, we are fulfilled; if it is not, we are not.

This is like saying that our felicity lies in achieving a state of entropy or heat death, which seems to be the agenda of the subatomic particles that must, in the last and rather tedious analysis, set in motion all our desires.

Adoption discloses a few of the myriad ways in which both evolution and culture soften, extend, and reticulate our rock-bottom interest in reproductive success. Rather than see these wrinkles as errors or perversions or mystifications, we should celebrate them. For without them love, art, science, and morality would not exist.

Proving that adoption is natural does not prove that it is a good thing. But it may have implications for policy— for how adoption is ordered, administered, encouraged, or discouraged. Parenthood turns out to be a rather elastic category, stretched this way and that by kinship, social or material advantage, error, deception, the ties of reciprocity, the needs of the community, and something for which the most hard-boiled scientist would be hard put to find a name other than love. In many animals, including humans, the drive we expect to be most deeply ingrained— the drive to reproduce— turns out to require little in the way of direct satisfaction. Most of us need sex, most of us need to raise a child, but the two don't have to be related. As a result, neither does the child.

One half of the above disjunction— that sex is worth having even when it doesn't produce children— has always been obvious. But the other half— that children are worth having even if your own sex act hasn't produced them— has yet to sink in. Standing on the child side of the divide, society tells us the connection is sacred. It tells us this is what we really want. It tells us anything else is second best. And it makes adoption absurdly difficult.

Imagine: You and your spouse have just undressed and climbed in bed, your future child a mutual gleam in your eyes. A throat is cleared: You look up to find a social worker at your bedside, clipboard on lap. Have you ever been arrested? Have you ever been treated for mental illness? What is your household income? May I see a bank statement, please?

While criminals, drug addicts, and psychopaths are free to beget children at will, would-be adoptive parents are guilty until proven innocent. Some kind of screen is called for, but one wonders if it need be so fine-meshed that would-be entrants feel like noxious insects.

There is much talk, notably in right-wing circles, of adoption as an alternative to abortion. Of the two, however, adoption arguably carries a greater stigma, at least for the birth mother. Thirteen states now require health insurers to cover expensive fertility treatment, which means, of course, that the public is footing the bill. Interest groups are lobbying Congress to make this a federal mandate. But adoption, which confers a far greater social benefit, is not covered under any health plan, despite the fact that it is a surer (and often cheaper) cure for childlessness than the knife, syringe, or test tube.

Reversing all this— really encouraging adoption, rather than giving it stammering, sporadic lip service— would benefit not only parentless children and childless adults but also society as a whole. While blond, blue-eyed newborns are scarce, both here and abroad there are children of nearly every other description waiting for placement. Moreover, in Oceania, in the Arctic, even in wolf packs, adoption builds community. By redistributing children in the social deck, it redistributes unevenly dealt resources. Modern adoption extends this web of benevolent kinship to embrace the nation and indeed the world.

Adoption may have begun, epochs ago, as a way of boosting one's own fitness by way of one's relatives, or as parasitism, or as reproductive error. But natural and cultural history have broadened it so that family extends beyond bloodlines, parasitism becomes a useful system of social roles, and reproductive error becomes love. Adoption urges us toward a more fluid sense of family, a broader sense of community. When we move beyond uncles and aunts as alloparents— when friends, godparents, neighbors, and shopkeepers become uncles and aunts— we move into a richer environment than the nuclear family can provide. Although modern adoption remains firmly within the nuclear orbit, it is inherently a part of this richer notion of child raising, this soup of relations that may be thicker, even, than blood.

One can only hope that vision appeals, because there may be no alternative. As the nuclear family fissions— as single, homosexual, divorced, and remarried parents become the rule — the standard model of parenthood must break down. And adoption will play a vital role in our new world.

Writing of divorce and remarriage, one popular author decries the "waste of love" involved in the raising of children by people who did not beget or bear them. I can't speak for stepparents, but the kind of adoption I know about seems not a waste but a magic barrel of love, never exhausted, never perhaps explained.

Birds of Different Feathers

The cuckoo and the cowbird are despised in human lore for laying eggs in the nests of other species. But many birds do this to members of their own species. In one population of bluebirds, for instance, it was found that 15 percent of the mothers were tending an unrelated nestling. Such egg dumping explains the fierce catfights between bluebird females. Cliff swallows in the American West go one better: Besides egg dumping, they airfreight prelaid eggs into neighbors' nests. The neighbor, if she notices, may not protest, since she has probably done the same thing herself. In the largest colonies, 22 to 43 percent of the nests harbor an alien egg. The practice may work to everyone's benefit: As cliff swallow nests are subject to rock slides, bad weather, and other catastrophes, it is unwise to keep all one's eggs in one basket.

Eggs cannot offer themselves for adoption, but chicks can and do in many bird species, especially those that breed in tightly packed colonies. If a white stork chick finds itself in an overcrowded nest, it may wander to a neighboring nest with fewer and younger chicks. Though chicks and parents will try to repel it, persistence pays: A study of three white stork colonies found that four out of 10 nests contained an adoptee. The runaways are fed better than they were before, but at some cost to their new nest mates. Similarly, ring-billed gull pairs that take in a foundling will, on average, fledge fewer chicks of their own than pairs that don't.

Why do they, then? Biologists speak of an "intergenerational conflict" or "coevolutionary arms race" between the gate-crashing youngsters and the unrelated, gatekeeping elders. Sometimes the youngsters win, sometimes the oldsters. The proportions may depend on who has the most to gain or lose— that is, on the selection pressure on each side.

Bluebirds who have to put food in their chicks' gaping mouths may work at four times their basal metabolic rate— roughly equivalent to a human chopping wood night and day. Ducks and geese, whose chicks start foraging shortly after hatching, pay far less for an extra beak. Adoption is often reported in these species, and not only by Hans Christian Andersen.

Creatures most prone to adopt don't always have a soft spot for infants. A mother herring gull that happens on another gull's chick will happily take it home and eat it. But sometimes, if the chick is still alive when the gull reaches the nest, she apparently will start feeding it, that is, adopt it.

Biologists, who do not readily ascribe compassion to any creature— least of all to a shrill-voiced cannibal— seem inclined to think that such a gull has had a senior moment. Finding herself with a live chick in her beak, she can't recollect whether she is bringing home takeout or collaring an errant offspring. Rather than chance eating her own chick, she takes the risk of raising someone else's. — E.E.

Even Fish Do It

Adoption is far from rare among mammals and birds, but among fish one could call it common. Paradoxically, the two very different evolutionary game plans favored by these two groups can both make adoption a good move. Mammals and birds produce a handful of offspring in which they invest heavily, mainly by feeding them. Fish take a more actuarial approach, laying eggs in vast quantities and trusting that some of them will survive. Once you are guarding a flock of fry, adding a few fry from another fish's brood won't cost you much effort.

It may even offer a payoff. If other fry are mixed in with your own, the chances that a predator will catch one of yours is correspondingly reduced: This is called the dilution effect. Your slight statistical edge may be sharpened by the confusion effect, whereby a hungry fish, dazzled by the sheer number of fry flying every which way, loses precious seconds deciding which to go after. If the adopted fry are smaller than your own, predators may seize on these easy pickings first. That is called the selfish shepherd effect. Finally, in some cases adopted fry may be placed on the edges of the brood, forming an edible buffer against marauders. That is called the selfish herd effect.

With this arsenal of effects, most of them confirmed to some degree by observation and experiment, Darwinists can make adoption seem less fishy, its low cost outweighed by palpable benefits.

Among some marine worms, meanwhile, adoption seems to be tied to finding a mate. Ophryotrocha diadema lays eggs in communal nurseries to which all roads, or rather mucous trails, lead. A worm couple will care for their own eggs, but eggs that are neglected will often be cared for by a worm that has not yet found a mate. That's because the nursery is also the place where mating takes place. A single worm that hangs out there, polishing someone else's eggs, markedly improves its odds of finding another. Thus the nursery doubles as a singles bar. — E.E.

The Web site of the National Adoption Information Clearinghouse, maintained by the U.S. Department of Health and Human Services, is a comprehensive resource on all aspects of adoption: www.calib.com/naic.

On November 24, 1998, President Clinton issued an Executive Memorandum to the Secretary of Health and Human Services on using the Internet to increase adoptions, especially in the foster care system. To read the initiative developed in response by the U.S. Department of Health and Human Services Administration for Children and Families, see www.acf.dhhs.gov/programs/cb/special/photolts/toc.htm.

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