The boy spoke in broken English and Spanish simultaneously. His mouth moved in a way that Stella was familiar with, shaping the sounds passing along both sides of his ridged tongue. Stella knew a fair amount of Spanish and tried to answer. The boy jumped up and down with excitement; he understood her! Talking to people was usually so frustrating for Stella, but this was even worse, because suddenly she knew what talking might really be.
Then she looked to one side and saw Kaye and Mitch.
Simultaneously, Kaye saw the woman in the kitchen window, using her phone. The woman did not look at all happy.
“Let’s go,” Mitch said, and Kaye did not disagree.
“Where are we going now?” Stella asked from her safety seat in the back of the Chevy Lumina as Mitch drove south.
“Mexico, maybe,” Kaye said.
“I want to see more like the boy,” Stella said, pouting fiercely.
Kaye closed her eyes and saw the boy’s terrified mother, grabbing him away from Stella, shooting a dirty look at Kaye; loving and hating her own child. No hope for bringing the two together again. And the woman in the window, too afraid to even come outside and talk with her.
“You will,” Kaye said dreamily. “You were very beautiful with the boy.”
“I know,” Stella said. “He was one of me.”
Kaye leaned over the back of the seat and looked at her daughter. Her eyes were dry, she had thought about this for so long, but Mitch rubbed his eyes with the back of his hand.
“Why did we have to leave?” Stella asked.
“It’s cruel to keep her away from them,” Kaye told Mitch.
“What are we going to do, ship her off to Iowa? I love my daughter and I want to be her father and have her in this family. A normal family.”
“I know,” Kaye said distantly. “I know.”
“Are there many like the boy, Kaye?” Stella asked.
“About a hundred thousand,” Kaye said. “We’ve told you that.”
“I would love to talk with them all” Stella said.
“She probably could, too,” Kaye said with a smile at Mitch.
“The boy told me about his cat,” Stella said. “He has two kittens. And the kids liked me, Kaye, Momma, they really liked me.”
“I know,” Kaye said. “You were beautiful with them, too.” Kaye was so proud and yet her heart ached for her daughter.
“Let’s go to Iowa, Mitch,” Stella suggested.
“Not today, Sweet Rabbit,” Mitch said.
The highway ran straight south through the desert.
“No sirens,” Mitch observed flatly.
“Did we make it again, Mitch?” Stella asked.
AFTERWORD
I’ve made a substantial effort in this novel to make the science accurate and the speculations plausible. The ongoing revolution in biology is far from over, however, and it is very likely that many of the speculations here will turn out to be wrong.
As I’ve done my research and spoken to scientists around the world, I’ve come away with an unshakable sense that evolutionary biology is about to undergo a major upheaval — not in the next few decades, but in the next few years.
Even as I finish revisions, articles are appearing in the scientific literature that support a number of speculative details. Fruit flies, it seems, can adapt in only a few generations to gross changes in climate. The implications of this are still controversial. The most recent, in the December — January 1998-99 issue of New Scientist, points up the contributions that human endogenous retroviruses might make to the progress of HIV, the AIDS virus; Eric Towler, of the Science Applications International Corporation, says he “has evidence that HERV-K enzymes may help HIV to evade potent drugs.” This is similar to the mechanism of swapped viral tool kits that frightens Mark Augustine.
The mystery, as it unfolds, will be absolutely fascinating; we truly are on the verge of discovering the secrets of life.
A SHORT BIOLOGICAL PRIMER
Humans are metazoans, that is, we are made up of many cells. In most of our cells there is a nucleus that contains the “blueprint” for the entire individual. This blueprint is stored in DNA (deoxyribonucleic acid); DNA and its complement of helper proteins and organelles make up the molecular computer that contains the memory necessary to construct an individual organism.
Proteins are molecular machines that can perform incredibly complicated functions. They are the engines of life; DNA is the template that guides the manufacture of those engines.
DNA in eucaryotic cells is arranged in two interwoven strands — the “double helix” — and packed tightly into a complex structure called chromatin, which is arranged into chromosomes in each cell nucleus. With a few exceptions, such as red blood cells and specialized immune cells, the DNA in each cell of the human body is complete and identical. Researchers estimate that the human genome — the complete collection of genetic instructions — consists of between sixty thousand and a hundred thousand genes. Genes are heritable traits; a gene has often been defined as a segment of DNA that contains the code for a protein or proteins. This code can be transcribed to make a strand of RNA (ribonucleic acid); ribosomes then use the RNA to translate the original DNA instructions and synthesize proteins. (Some genes perform other functions, such as making the RNA constituents of ribosomes.)
Many scientists believe that RNA was the original coding molecule of life, and that DNA is a later elaboration.
While most cells in the body of an individual carry identical DNA, as the person grows and develops, that DNA is expressed in different ways within each cell. This is how identical embryonic cells become different tissues.
When DNA is transcribed to RNA, many lengths of nu-cleotides that do not code for proteins, called introns, are snipped out of the RNA segments. The segments that remain are spliced together; they code for proteins and are called exons. On a length of freshly transcribed RNA, these exons can be spliced together in different ways to make different proteins. Thus, a single gene can produce a number of products at different times.
Bacteria are tiny single-celled organisms. Their DNA is not stored in a nucleus but is spread around within the cell. Their genome contains no introns, only exons, making them very sleek and compact little critters. Bacteria can behave like social organisms; different varieties both cooperate and compete with each other to find and use resources in their environment. In the wild, bacteria frequently come together to create biofilm “cities”; you may be familiar with these cities from the slime on spoiled vegetables in your refrigerator. Biofilms can also exist in your intestines, your urinary tract, and on your teeth, where they sometimes cause problems, and specialized ecologies of bacteria protect your skin, your mouth, and other areas of your body. Bacteria are extremely important and though some cause disease, many others are necessary to our existence. Some biologists believe that bacteria lie at the root of all life-forms, and that eu-caryotic cells — our own cells, for example — derive from ancient colonies of bacteria. In this sense, we may simply be spaceships for bacteria.
Bacteria swap small circular loops of DNA called plas-mids. Plasmids supplement the bacterial genome and allow them to respond quickly to threats such as antibiotics. Plasraids make up a universal library that bacteria of many different types can use to live more efficiently.
Bacteria and nearly all other organisms can be attacked by viruses. Viruses are very small, generally encapsulated bits of DNA or RNA that cannot reproduce by themselves, Instead, they hijack a cell’s reproductive machinery to make new viruses. In bacteria, the viruses are called bacterio-phages (“eaters of bacteria”) or just phages. Many phages carry genetic material between bacterial hosts, as do some viruses in animals and plants.