Every mother is a chimera made up of her own genetic cells living side by side with the cells of every child she has ever carried.

The miracle of birth is always a sacred moment, but it is not the first moment of your existence. You did not suddenly come into being on the day you were born. Your birthday is the day you first showed your face to the outside world, but it was already your face for months before anybody saw it.

During those months you were not a part of your mother’s body. Your growth and development were self-directed. Your mother provided a safe place and nutrition, but she didn’t add anything to your being.

This should not, however, leave us thinking that mothers and their children are disconnected and distant. While it remains true that the human organism directs its own development from the zygote stage all the way through adulthood, this isn’t the whole story. There are four recent discoveries that testify to the beautifully deep relationship between a mother and her child.

First, let’s talk about mitochondria. These are the tiny “engines” in your cells that generate the energy of life (ATP synthesis). Mitochondria have DNA all their own, differing from the DNA of the cells in which they work. While their numbers can vary widely, from only a few to more than 2,000, the typical cell has around 50-100.

Here’s the remarkable fact: DNA analysis shows that all of your mitochondria are from your mother! Within moments of sperm-egg fusion, immediately after you came into being, the mitochondria from your father’s sperm (which was the mitochondria of your paternal grandmother) was selectively destroyed so that only your mother’s remained.

Throughout the rest of your life, the powerhouses of your every cell are descended from your mother. And if you become a mother, your children will inherit the same mitochondrial strain.

There’s more! Not only the mitochondria but also the entire cytoplasm of your mother’s egg became your own cytoplasm at conception. (The cytoplasm is the gel-like substance in the cell surrounding the nucleus.) It is filled with proteins, RNA and a variety of organelles besides mitochondria. All these things have an essential role in making you who you are.

With all the genetic tinkering that we have grown accustomed to hearing about, many people have been led to the false and simplistic conclusion that we are merely the sum total of our DNA. This is not true.

Our DNA provides the raw material for our development. It sets the boundaries for what we can and cannot be. But there are billions of variations within these boundaries that are decided by the way that your cytoplasm interprets and expresses the DNA. It alone determines when certain genes are turned on, when they are turned off, how long they are kept on and to what degree. All these factors working on identical genes can produce remarkably different people.

This is why identical twins — even clones — are never quite identical. They are twins in that their DNA is identical, but they are unique because their identical DNA was actuated within different cells by different cytoplasm. What is beautiful and remarkable for our little meditation on motherhood is this: all these differences are completely determined by the mother. The father has no influence over them.

So, not only are the tiny powerhouses that energize your cells inherited from your mother, but also your height, musculature, hair color, and a million other traits are the result of the unique cytoplasm inherited from your mother. This, and this alone, determined how your DNA would be interpreted and expressed to make you unique.

A third remarkable fact of motherhood is in the phenomenon of the “fetal microchimera.” A chimera is “an individual … with two or more genetically distinct populations of cells” (Merriam-Webster). The most common way to form a chimera artificially is by means of organ transplant. A donor kidney transplants the unique DNA of the donor into the body of the recipient, and as that kidney continues to live within the recipient, its cells continue to replicate the donor’s DNA.

But the more common chimera, by far, is completely natural. It happens whenever a woman gets pregnant, but it is not the pregnancy itself that is a chimera. In the pregnancy, a unique person with genetically distinct cells is growing within her. This person is self-directing and not dependent upon his mother for his substance, only for nourishment and a hospitable environment.

But that doesn’t mean there is no bond between mother and child. Rather, cells from the developing child always cross the placenta wall and enter into the mother’s body. These cells tend to cluster and form colonies in various places within the mother. One child may leave a colony of cells in her brain; another child’s cells may be found in her liver, or in her heart. Every mother is a chimera made up of her own genetic cells living side by side with the cells of every child she has ever carried – even of those that did not make it to term.

While the effects of fetal microchimerism are still largely a mystery, some studies suggest that they extend health benefits to the mother’s immune system, and may even act as stem cells to repair a mother’s damaged organs. It may also explain what so many men wonder at. How can mothers have such an incredibly strong bodily connection to their children?

Whatever purpose it serves, this fact of biology is a gift and blessing given only to mothers. No man can ever experience it. She can keep living souvenirs in her body from every child she has conceived.

This inspires a new line for the popular carol: “Mary, did you know that the flesh of Jesus always lives within you?” It puts a new spin on Luke’s observation: “Mary kept all these things, and pondered them in her heart” (Luke 2:19).

The fourth part of our motherly meditation comes from a study recently released by the University of British Columbia.

“The study, published Nov. 22 in Development and Psychopathology, involved 94 healthy children in British Columbia,” reads a press statement on the study. “Researchers from UBC and BC Children’s Hospital asked parents of 5-week-old babies to keep a diary of their infants’ behavior (such as sleeping, fussing, crying or feeding) as well as the duration of caregiving that involved bodily contact. When the children were about 4 ½ years old, their DNA was sampled by swabbing the inside of their cheeks.”

After analyzing the DNA swabs of their sample group, they were able to see healthier, more mature cells in those infants that received more comforting bodily contact. Four years later, the mother’s touch was still felt!

This is utterly remarkable. The comfort and support that a mother gives her infant child is not only emotional or spiritual. It has scientifically detectable effects upon the body at the chromosomal level.

So, mothers, don’t sell yourselves short. The child you carried may have been an independent and self-directing human being, but he was not disconnected from you. You supplied the interpretive environment to build a body from his DNA. You provided the mitochondria that still powers his cells. You received a life-long souvenir in his living cells, still thriving in your body. And your every caress and kiss and coo made his body strong.

These are only four recently discovered phenomena. These glorious connections have bonded mothers and children for millennia before we ever discovered them. What other wonders still remain to be learned?