Say What?!

Although I grew up outside of Chicago, I’ve spent the last decade split between the East and West Coasts. Now, after 5 years in Los Angeles, my husband and I are settling into life as Michiganders. Aside from the longer days and lower cost of living, the biggest differences I’ve noticed are linguistic. People speak differently here, and for me it’s like coming home. After a decade away, I am back in a state where people drink pop instead of soda. And, at long last, I’ve returned to the land of the Northern City Vowel Shift.

Speech is constantly in flux, whether or not we are aware of it. Regional dialects diverge, giving us the drawls of the South and the dropped r’s of the Northeast. More recently, cities in a large swath of the northern Midwest are reinventing their vowels, especially the short vowels in ben, bin, and ban. From Syracuse to Minneapolis, Green Bay to Cleveland, these vowels have been changing among Caucasian native English speakers. The vowels are now pronounced with a different positioning of the tongue, in some cases dramatically altering the sound of the vowel. A wonderful NPR interview on the subject is available online in audio form and includes examples of these vowel changes.

I must have picked up the Northern City vowels growing up near Chicago. When I arrived in Boston for graduate school, friends poked fun at my subtle accent. They loved to hear me talk about my can-tact lenses. And I can’t blame them for teasing me. The dialect can sound pretty absurd, especially when pushed to the extreme. It was probably best parodied by George Wendt and the SNL cast in the long-running Super Fans sketch.

I have long been in love with the field of phonetics and phonology, or how we produce and perceive speech sounds. Creating and understanding speech are two truly impressive (and often underappreciated) feats. Each time we speak, we must move our tongues, lips, teeth and vocal folds in precise and dynamic ways to produce complex acoustical resonances. And whenever we listen, we must deconstruct the multifaceted spectral signatures of speech sounds to translate them into what we perceive as simple vowels, consonants, syllables. We do all of that without a single conscious thought – leaving our minds free to focus on the informational content of our conversations, be they about astrophysics or Tom and Katie’s breakup.

Experiences in the first couple years of life are critical for our phonetic and phonological development. Details of the local dialect are incorporated into our speech patterns early in life and can be hard to change later on. As a result, everyone’s speech is littered with telltale signs of their regional origins. My mother and aunt spent their early years in a region of Kansas where the vowels in pen and pin were pronounced the same. To this day, they neither say nor hear them as different. Imagine the trouble my mother had when she worked with both a Jenny and Ginny. I’ve noticed major differences between my husband’s dialect and my own as well. My husband, a native Angeleno, pronounces the word dew as dyoo, while I pronounce it as doo because in Chicago the vowels yoo and oo have merged.

These days I’m watching phonetic development from a front-row seat. My baby has been babbling for a while and I’ve watched as she practiced using her new little vocal tract. She would vocalize as she moved her tongue all around her open mouth and presumably learned how the sound changed with it. From shrieks to gasps to blowing raspberries, she tested the range of noises her vocal tract could create.  And as she hones in on the spoken sounds she hears, her babbling has become remarkably speech-like. The consonants and vowels are mixed up in haphazard combinations, but they are English consonants and vowels all right. Through months of experimentation, mimicry, and practice, she has learned where to put her tongue, how far to open her mouth, and how to shape her lips to create the sounds that are the building blocks of our language. And just as she was figuring it out, we went and moved her smack into a different dialect. She will have to muddle through and learn to speak all the same. And once that happens, it will be interesting to see where her sweet little vowels end up.

On Nano-Naps and Dreamscapes

New mothers must be collectors of broken sleep, eagerly taking a sliver here, a shard there – whatever they can get.

Now that my baby is four months old, she’s finally sleeping at night. Still, she wakes me every two hours to nurse. She is half asleep while she feeds and I am always nodding off. In the few seconds it takes for my sinking head or my nursing baby to summon me back, I’ll have a momentary dream. A micro-dream. A nano-nap. No more intricate dreams of forgetting to do my homework or going to prom in a maternity dress. These dreams are all business: snapshots of everyday life. Once it may be a view of my husband lifting the baby out of her crib. Another time, I glimpse a lump in bed beside me and realize it’s my baby buried in our blankets (a terrifying dream.) But usually I simply dream that she’s nursing. A dream of mere reality: no more, no less.

How do I even know that I’m dreaming? The details are off. And in these cases, the switch from dreaming to wakefulness can be particularly strange. Once the transition felt as seamless as a change of camera shots in a television show. One moment I was looking down at my nursing baby; the next, she was flipped (mirror-reversed) in my arms and her head was noticeably smaller! Never before have I had such an immediate comparison between the mind’s eye and the naked eye, nor realized how very similar they feel. And never before have I had such uninventive, literal dreams. It’s as if I can’t muster the energy to dream up anything better.

In the face of my lackluster dreaming, I am all the more fascinated by the rich dream life of my daughter. From the day she was born I’ve watched her smile, pout, and wince and heard her scream and giggle madly in her sleep. In fact, she smiled in her sleep months before she gave us her first waking smile. Physicians have observed rapid eye movements in fetuses, suggesting that babies dream in the womb. But what are they dreaming of? Is it limited to what they know: heartbeats and jostling and amniotic fluid? Or perhaps their dreams are wilder than our own, unconstrained by the realities of life on this earth. After all, the infant brain contains legions of unpruned synapses and far more neurons than that of an adult. Who’s to say what sort of fantasy it might come up with?

Whatever sort of dreams a newborn has, we don’t remember them as adults. By late infancy, we’ve already pruned enough synapses and experienced enough of the world to have a basic vocabulary for our dreams. An adult’s dream may create some odd combinations – eyeballs growing on trees or hats that unfurl into snakes – but the vocabulary, the unitary elements, are fixed. Eyeballs, trees, hats, snakes. Grow, unfurl. Our potential dreamscapes are wholly constrained by the details of our waking existence.

As my baby examines new places and things, I am reminded that she’s cobbling together her own vocabulary of the world. She will store away sensations, objects, creatures, actions, concepts, cultures, and myths. A knowledge that the sun shines from above and plants sprout from below. That rivers run and lakes loiter. That caterpillars turn into butterflies and never the other way around. For better or for worse, her future dreams will be shaped by the idiosyncrasies of our funny little world.

Divvying Up Baby

I recently bought my baby new pajamas with a decal that says, “50% Dad + 50% Mom = 100% Me!” I couldn’t resist an outfit that doubles as both math and biology lessons. But on further reflection, I’ve realized that this simple formula is wrong in more ways than one.

To begin with, my baby doesn’t look like she’s 50% Mom. At best, she looks about 10% Mom. I’ve written before about how our daughter would be a mixture of traits from European and Indian peoples, reflecting her mom and dad’s respective heritages. Yet she arrived looking like a wholly Indian baby. This is fine, of course. I think she’s absolutely perfect with her caramel skin and jet black eyes and hair. But it’s hard to keep a straight face when friends politely ask us who we think she resembles. And when I’m out with her in public I’m aware that I look like her nanny, if not someone who’s stolen a baby. She truly doesn’t look like she’s mine.

How else is the formula wrong? Genetically. Sure, our daughter’s nuclear genes are comprised of DNA sequences from both my husband and me. But she has another sort of DNA in her body, one that literally outweighs the conventional type. This DNA lives in her mitochondria, the bacteria-like structures that populate our every cell. Mitochondria are like tiny internal combustion engines, generating all of our energy through respiration and releasing heat that makes us warm-blooded animals. Although mitochondria don’t have many actual genes, they each carry several copies of those genes. Multiply that by the 10 million billion or so mitochondria in our bodies and you’ll find that we each contain more DNA by weight for mitochondria than humans. And these mitochondrial genes are inherited entirely from the mother.

Mitochondrial genes can’t claim credit for your eye color, jaw shape, or intrinsic disposition. Their reach is mostly limited to details of your metabolism and your susceptibility to certain diseases. But mitochondrial DNA is significant for another reason: scientists use it to trace human lineages across the globe. After all, they don’t get reshuffled in each generation as our nuclear genes are. Mitochondrial inheritance can be traced back hundreds of thousands of years, following the maternal lineage at every generation. Unlike the historian’s genealogy, which often follows surnames passed down from fathers, the scientist’s genealogy is a tree built of mothers alone.

So it is through our mothers that our heritages can be traced into the distant past. In every one of her cells, my baby carries a map leading back through me and my mother and her mother and beyond . . . unbroken all the way back to our earliest origins as modern humans. And since my baby is a girl, she can continue that line. So long as she has a daughter and she has a daughter and so on, I will remain a part of that ongoing chain.

My condolences to all you men out there. Same to all you women who only had sons. You’ve passed on your nuclear genes and your child may be the spitting image of you, but your mitochondrial chain has been broken and you will be left out of the biologist’s tree. Although my daughter looks classically Indian, her mitochondrial DNA reveal only her European lineage. Despite the hair, eyes, and skin she inherited from her daddy, my baby’s mitochondria are mine all mine. She and I are links in a traceable chain of human life while my husband is nowhere to be found.

That’s something I can remember the next time I’m mistaken for the nanny.

Halfsies!

My husband spotted another one yesterday. A half-Indian, half-Caucasian blend. The woman had an Indian first and last name, but her features were more typical of a Persian ethnicity than either Indian or white. My husband overheard her describing her heritage and smiled. These days, with a half-Indian, half-white baby on the way, we’re hungry for examples of what our baby might look like. We’ve found a few examples among our acquaintances and some of my husband’s adorable nieces and nephews, not to mention the occasional Indian-Caucasian celebrity like Norah Jones. We think our baby will be beautiful and perfect, of course, although we’re doubtful that she’ll look very much like either one of us.

Many couples and parents-to-be are in the same position we are. In the United States, at least 1 in 7 marriages takes place between people of different races or ethnicities, and that proportion only seems to be increasing. It’s a remarkable statistic, particularly when you consider that interracial marriage was illegal in several states less than 50 years ago. (See the story of Loving Day for details on how these laws were finally overturned.) In keeping with the marriage rates, the number of American mixed race children is skyrocketing as well. It’s common to be, as a friend puts it, a “halfsie.” At least in urban areas like Los Angeles, being mixed race has lost the negative stigma it had decades ago and many young people celebrate their mixed heritages. Their unique combinations of facial and physical features can be worn with pride. But the mixture goes deeper than just the skin and eyes and hair.

At the level of DNA, all modern humans are shockingly similar to one another (and for that matter, to chimpanzees). However, over the hundreds of thousands of years of migrations to different climates and environments, we’ve accumulated a decent number of variant genes. Some of these differences emerged and hung around for no obvious reason, but others stuck because they were adaptive for the new climates and circumstances that different peoples found themselves in. Genes that regulate melanin production and determine skin color are a great example of this; peoples who stayed in Africa or settled in other locations closer to the Equator needed more protection from the sun while those who settled in sites closer to the poles may have benefited from lighter skin to absorb more of the sun’s scarce winter rays and stave off vitamin D deficiency.

In a very real way, the genetic variations endemic to different ethnic groups carry the history of their people and the environments and struggles that they faced. For instance, my husband’s Indian heritage puts him at risk for carrying a gene mutation that causes alpha thalassemia. If a person inherits two copies of this mutation (one from each parent), he or she will either die soon after birth or develop anemia. But inheriting one copy of the gene variant confers a handy benefit – it makes the individual less likely to catch malaria. (The same principle applies for beta thalassemia and sickle cell anemia found in other ethnic populations.) Meanwhile, my European heritage puts me at risk for carrying a genetic mutation linked to cystic fibrosis. Someone who inherits two copies of this gene will develop the debilitating respiratory symptoms of cystic fibrosis, but thanks to a handy molecular trick, those with only one copy may be less susceptible to dying from cholera or typhoid fever. As the theory goes, these potentially lethal mutations persist in their respective populations because they confer a targeted survival advantage.

Compared to babies born to two Indian or two Caucasian parents, our baby has a much lower risk of inheriting alpha thalassemia or cystic fibrosis, respectively, since these diseases require two copies of the mutation. But our child could potentially inherit one copy of each of these mutations, endowing her with some Suberbaby immunity benefits but also putting her children at risk for either disease (depending on the ethnicity of her spouse).

The rise in mixed race children will require changes down the road for genetic screening protocols. It will also challenge preconceived notions about appearance, ethnicity, and disease. But beyond these practical issues, there is something wonderful about this mixing of genetic variants and the many thousands of years of divergent world histories they represent. With the growth in air travel, communication, and the Internet, it’s become a common saying that the world is getting smaller. But Facebook and YouTube are only the beginning. Thanks to interracial marriage, we’ve shrunk the world to the size of a family. And now, in the form of our children’s DNA, it has been squeezed inside the nucleus of the tiny human cell.

Locked Away

The results are in. The ultrasound was conclusive. And despite my previously described hunch that our growing baby is a boy, she turned out to be a girl. We are, of course, ecstatic. A healthy baby and a girl to boot! As everyone tells us, girls are simply more fun.

As I was reading in my pregnancy book the other day, I came across an interesting bit of trivia about baby girls. At this point in my pregnancy (nearly 6 months in), our baby’s ovaries contain all the eggs she’ll have for her entire life. As I mentioned in a prior post, the fact that a female fetus develops her lifetime supply of eggs in utero represents a remarkable transgenerational link. In essence, half of the genetic material that makes up my growing baby already existed inside my mother when she was pregnant. And now, inside me, exists half of the genetic material that will become all of the grandchildren I will ever have. This is the kind of link that seems to mix science and spirituality, that reminds us that, though we are a mere cluster of cells, there’s a poetry to the language of biology and Life.

But after stumbling upon this factoid about our baby’s eggs, I was also struck by a sense that somewhere someone seemed to have his or her priorities mixed up. If our baby were born today, she would have a slim chance of surviving. Her intestines, cerebral blood vessels, and retinas are immature and not ready for life outside the womb. Worse still, the only shot her lungs would have at functioning is with the aid of extreme medical intervention. The order of it all seems crazy. My baby is equipped with everything she’ll need to reproduce decades in the future, yet she lacks the lung development to make it five minutes in the outside world. What was biology thinking?

Then I remembered two delightful popular science books I’d read recently, The Red Queen by Matt Ridley and Life Ascending by Nick Lane. Both described the Red Queen Hypothesis of the evolution of sex, which states that the reason so much of the animal kingdom reproduces sexually (rather than just making clones of itself) is to ‘outwit’ parasites. In short, if each generation of humans were the same as the next, parasites large and microbial could evolve to overtake us. By mixing up our genetic makeup through sexual reproduction, we make it harder for illnesses to wipe us out. Like the Red Queen from Lewis Carroll’s classic, we keep running in order to stay in the same place (which is one step ahead of parasites and disease).

Just as there are parasitic organisms and bacteria, one might say that there are parasitic genes. For example, mutations in the DNA of our own replicating cells can cause cancer, which is essentially a self-made, genetic parasite. Moreover, retroviruses like HIV are essentially bits of genetic material that invade our bodies and can insert themselves into the DNA of our cells. And the ultimate road to immortality for a parasitic gene would be to hitch a ride on the back of reproduction. Imagine what an easy life that would be! If a retrovirus could invade the eggs in the ovaries, it would be passed on from one generation to the next without doing one iota of work. It’s the holy grail of parasitic invasion – get thee to the ovaries! According to Matt Ridley in another of his books, The Origins of Virtue, the human germ line is segregated from the rest of the growing embryo by 56 days after fertilization. Within two months of conception, the cells that will give rise to all of the embryo’s eggs (or sperm, in males) are already cordoned off. They are kept safe until they are needed many years in the future.

So perhaps my little baby’s development isn’t as backwards as it seemed at first. Yes, lungs are important. But when you’ve got something of value to others, it makes practical sense to hurry up and lock it away.

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