Drew - I, mammal: the story of what makes us mammals

Also available in the Bloomsbury Sigma series:

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For Mariana, Isabella and Cristina.

And for Cliff

Contents

Of animals, some resemble one another in all their parts, while others have parts wherein they differ.

Aristotle

In the standard modern fashion, Cristina went to the bathroom, and I paced the living room. That month had been our fifth attempt to fall pregnant but thefirst that Cristinas clockwork body had suggested it was worthwhile taking a plastic strip from the box; a strip that would tell us if a nascent placenta was already releasing a stream of hormones into its mothers blood.

Seven months later, eight weeks early, Isabella was born. The morning after, I sat at Cristinas bedside exhausted and shocked. Isabella was too immature to suckle, and we were uncertain if her mothers body was ready to lactate, so I watched for 20 minutes as Cristina compressed and released a handheld plastic pump. Finally, with a tiny plastic syringe, she collected a few droplets of colostrum from around her nipples. In the ward where Isabella slept, our nurse, whose scrubs we came to suspect concealed a pair of angel wings, held aloft that syringe and reacted as if Cristina were the finest dairy cow at the county fair. He added those drops of new milk to the formula hed prepared and gently pushed the mixture through a plastic tube that passed from Isabellas mouth to her stomach.

Soon, that handheld pump was replaced by a heavy electrical contraption, and as Isabella stayed in hospital, our nights at home those first weeks were broken not by newborn wailing but by the mechanical whirring of Cristinas determination. Only when Isabella was a month old did a nurse called Joy suddenly say that it was time she tried a bottle. Tense with anticipation, we watched Joy move the rubber teat toward Isabellas tube-free mouth then we gasped, beamed, and felt a knot of anxiety unravel as Isabella suckled for the first time.

Cristina now took to circling a nipple before Isabella, and, after another week, Isabella latched on. It was a moment of pure jubilation. Flushed with awe, happiness and relief, I sat entranced by the rhythmic formation and relaxation of a dimple in my daughters cheek.

I did not, at that point, think, Look at my partner and daughter engaging in a uniquely mammalian activity. Certainly, I knew this was the case, but Im not sure that I did a whole lot of thinking in those weeks, not in any protracted or intellectual sense. I merely reacted and responded. And felt. I felt things very acutely. I was using unfamiliar parts of my brain. I was powered by something new.

Isabella was in hospital for two months, the first of which was the most gruelling of both Cristinas life and mine. But it was also joyous. The neonatal intensive care unit continually swung us between moments of blissful parental contentment and black wells of helpless what-if ? These were fears of a new magnitude; fears that seemed to feed on the energy of the happiness they trampled.

As often as possible, wed remove Isabella from her temperature-controlled crib and rest her on our chests, Cristinas usually. Kangaroo Care they called it. But most of my time there, I sat quietly beside the crib as my daughter slept. Id talk a little, insert a sterilised hand through the plastic portal to ensure she knew I was there, and with all my strength will her well.

I pleaded for Isabellas body to do where it was what it should have done inside a womb. My focus was whatever the doctors had been most concerned about that day. Sometimes it was her GI tract, other times it was her breathing or feeding I would cast in my mind a picture of her lungs, say, and the nerves that should have been controlling them, and implore those structures to develop as they should, for the nerves to reach out and grip their intended targets.

The day before what had once been Isabellas due date we departed the hospital. The three of us descended a lift shaft as if it were a second birth canal expelling us together into the world. Isabella was fragile, but she was healthy. We were lucky.

I am now a more grateful person, but the fall-out was greater than that. I witnessed too the physical toll taken by pregnancy, birth and breastfeeding. The two of us, Cristina especially, waded through previously unknown sleeplessness and exhaustion. I watched her become a mother psychically as well as physically, as I too experienced fatherhood hijack my psyche. I changed. Before, Id seen myself primarily as a free-floating cerebrum, a mind, a stream of cognition: I had thought, therefore I had been . And now it was different. For 20 years, Id studied biology; finally, I understood that I was biology.

The first chapter of this book is an investigation into why the vast majority of male mammals carry their testicles in wrinkled carry cases beyond the safety of their abdomens, and it was written as a standalone article before Cristina and I embarked upon becoming parents. (Indeed, after each failure to become pregnant, we wondered about the errant football thats painfully felt impact had inspired that story.) When Slate published the article after Isabellas birth, I thought that was the end of it. But then after months of obsessing over feeding Isabella I found myself plotting a similar survey of what evolutionary biology had to say about the origins of lactation.

Milk, like the scrotum, was a biological peculiarity seen only in mammals. No other type of animal feeds its young as mammals do; indeed, mammary glands inspired the very name mammal. The terrain felt familiar, a theme was emerging I was back inside ancient mammalian history considering how, aeons ago, a very particular type of animal had evolved a very particular new trait, a trait that shaped the way I now lived. And thinking more widely about the things that had preoccupied me since becoming a father, many of them, I saw, had been quintessentially mammalian. Our daughter had developed inside a womb, nourished by a placenta. In the hospital, her temperature had been carefully monitored to ensure that she remained warmer than her surroundings. And werent the emotional upheavals of becoming parents also pretty mammalian things to have happened? Certainly, the brain that had driven this transition that had wrestled with attachment and anxiety, and that had rendered everything as an experiential reality was covered in a folded sheet of grey matter that existed only in mammals.