an incoming fan made up of signals from e-mail programs, Web browsers, and all sorts of other software, each with its own peculiar sorts of information processing. In order for this stream of data to get onto the Internet, it must first be turned into a code that obeys the Internet’s protocols. These data streams move from personal computers to servers and then into a small core of routers. The signals can then flow into an outgoing fan of pathways, toward another computer, where the standard stream of data can be converted into a picture, a document, or some other peculiar form.
In both the Internet and
E. coli,
the bow tie knot allows each network to function even when parts of it fail. A mutation that destroys one metabolic reaction will not kill
E. coli
because in the knot there are other pathways onto which it can still shunt carbon. The Internet can continue sending messages even after one of the servers shuts down because it can move the messages through another pathway.
The bow tie architecture also saves energy in both systems. If
E. coli
did not have a bow tie, it would have to create a dedicated pathway of enzymes to make every molecule it needed. Each of those enzymes would require its own gene. Instead,
E. coli’
s pathways all dump their products into the same network in the knot of the bow tie. Likewise, the Internet does not have to link every computer directly to every other one, or use special codes for every kind of file it carries. In both cases this arrangement is possible only because the entire network obeys certain rules. On the Internet every message must be converted into the same data packets. In
E. coli
all energy transfers must use the same currency: ATP.
The inventors of the Internet did not realize they were creating this kind of network. They were only trying to balance cost and speed as they joined servers together. But unintentionally they created a model of
E. coli
that spans the Earth.
VIVE LA DIFFÉRENCE
We all have our own tastes. I don’t understand why some people eat snails. I can’t say for sure why I dislike them, but I can certainly think up a few stories. Maybe I have a certain kind of sensor on the cells of my tongue that goes into a spasm of dismay. Or maybe some network of neurons in my brain associates the taste of snails with some awful memory from my distant past. Or maybe I simply never had the opportunity to come to love snails because I grew up eating pizza and hamburgers and peanut butter. The gastronomic window has now closed.
I have no way of knowing whether any of those possibilities is true. I can’t go back in time, replay my life from the moment of conception, and see if a plate of escargots served at kindergarten lunch would have made a difference. I can’t clone myself a hundred times over and send my manufactured twins to foster homes in France. I am a single, useless snail-loathing datum.
My distaste for snails is a minor example of a major fact: life is full of differences. We humans differ from one another in ways too many to count. We are shy and bold, freckled and pale, truckers and hairdressers, Buddhists and Presbyterians. We get cancers in third grade and live for a century. We have fingerprints.
Scientists have only a rough understanding of how this diversity arises. We are not merely the output of software written in a programming code of DNA. As we develop in the womb, our genes interact with signals from our mothers. The environment continues to influence those genes in unpredictable ways after birth. The food we eat, the air we breathe, the traumas and joys and boredom of childhood, and all the rest have an influence on which genes become active. Our differences are not just hard to trace but a source of pride. We can produce greatness of all kinds: Babe Ruths and Frédéric Chopins, Mae Wests and Marie Curies. They are products of our complexity, of a species in which each individual carries 18,000 genes that can become 100,000
In both the Internet and
E. coli,
the bow tie knot allows each network to function even when parts of it fail. A mutation that destroys one metabolic reaction will not kill
E. coli
because in the knot there are other pathways onto which it can still shunt carbon. The Internet can continue sending messages even after one of the servers shuts down because it can move the messages through another pathway.
The bow tie architecture also saves energy in both systems. If
E. coli
did not have a bow tie, it would have to create a dedicated pathway of enzymes to make every molecule it needed. Each of those enzymes would require its own gene. Instead,
E. coli’
s pathways all dump their products into the same network in the knot of the bow tie. Likewise, the Internet does not have to link every computer directly to every other one, or use special codes for every kind of file it carries. In both cases this arrangement is possible only because the entire network obeys certain rules. On the Internet every message must be converted into the same data packets. In
E. coli
all energy transfers must use the same currency: ATP.
The inventors of the Internet did not realize they were creating this kind of network. They were only trying to balance cost and speed as they joined servers together. But unintentionally they created a model of
E. coli
that spans the Earth.
VIVE LA DIFFÉRENCE
We all have our own tastes. I don’t understand why some people eat snails. I can’t say for sure why I dislike them, but I can certainly think up a few stories. Maybe I have a certain kind of sensor on the cells of my tongue that goes into a spasm of dismay. Or maybe some network of neurons in my brain associates the taste of snails with some awful memory from my distant past. Or maybe I simply never had the opportunity to come to love snails because I grew up eating pizza and hamburgers and peanut butter. The gastronomic window has now closed.
I have no way of knowing whether any of those possibilities is true. I can’t go back in time, replay my life from the moment of conception, and see if a plate of escargots served at kindergarten lunch would have made a difference. I can’t clone myself a hundred times over and send my manufactured twins to foster homes in France. I am a single, useless snail-loathing datum.
My distaste for snails is a minor example of a major fact: life is full of differences. We humans differ from one another in ways too many to count. We are shy and bold, freckled and pale, truckers and hairdressers, Buddhists and Presbyterians. We get cancers in third grade and live for a century. We have fingerprints.
Scientists have only a rough understanding of how this diversity arises. We are not merely the output of software written in a programming code of DNA. As we develop in the womb, our genes interact with signals from our mothers. The environment continues to influence those genes in unpredictable ways after birth. The food we eat, the air we breathe, the traumas and joys and boredom of childhood, and all the rest have an influence on which genes become active. Our differences are not just hard to trace but a source of pride. We can produce greatness of all kinds: Babe Ruths and Frédéric Chopins, Mae Wests and Marie Curies. They are products of our complexity, of a species in which each individual carries 18,000 genes that can become 100,000
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