Evolution

Evolution - or survival of the fittest (or luckiest) - is a readily provable fact, and one not limited to species: Evolution also applies to ideas (memes) with areas as diverse as religion, music, fairy tales, and urban legends.

The concept of evolution is simple: That which successfully reproduces, survives. If pressures (due to competition or predation) limit the growth of something which has a natural variation (a choice of religions, or music genres, or tales, or an ecosystem, or apes), those variants which most successfully reproduce will succeed versus those less suitable, or less lucky.

Note how few successful religions abound which forbid sex. There have been short term experiments in this direction. More subtly, religions that don't have a strong philosophy of proselytism tend to be dominated by those that do. Remember, survival of the fittest is really just survival of those that successfully reproduce. See The Purpose of Life.

Evolution of species continues today. Mankind is forcing change, which drives evolution. Some of this is merely speeding long term trends (such as reduced success of amphibians in general, or the loss of many marginal species like the spotted owl). Other changes are more worrisome (such as the evolution of anti-biotic resistant bacteria).

Especially with animals (including humans), there are two forces that dominate evolutionary pressures. In addition to reproductive success due to superior survival characteristics, there is reproductive success due to sexual selection (ie, how members of each sex choose mates). More colorful animals are easier to find, and the most showy male is likely to get the most females and successfully reproduce even though he is also the most visible to predators and ends up living a shorter life. Sexual selection may also explain extremely large sauropod dinosaurs; perhaps the males/females liked (or could see) tall females/males better - and sought them as mates - leading to runaway selection for this feature.

Even mankind continues to evolve in several ways, and indeed demonstrates evidence of very recent evolution.

For example, there is strong evidence that people have been evolving for external sexual characteristics. Human females have proportionally larger breasts, narrower waists, and broader hips than other primates. (As a human male, I do love that shape.) Human males have shapes that illustrate upper body strength, and have a penis that is larger in proportion to body size than any other ape. Apparently males have been selecting for large breasts and hips (especially in contrast to waist size). And women have been selecting men with broad shoulders, large muscles, and a big penis. And bad boys, at that.

Watching many reality shows (and especially MTV) suggests that human females are still actively selecting for strength, size, and sexual prowess; intelligence is clearly not a requirement. Likewise for human males, actively selecting voluptuous, athletic females with exotic eyes, long hair, and aggressive sexual attitudes.

Our technology is also having a significant effect on the human specie: we are becoming less diverse, as our ability to travel globally is reducing regional and racial disparities at measurable rates. In a few thousand years, there may be no remaining significant racial differences at all as we continue to interbreed and blend. Personally, I think this is a good thing.

We are also enabling the survival and allowing the reproduction of humans who would never live to adulthood without technology and/or large social organizations to care for them. I think this is a bad thing (when genetically caused), as I prefer that our children be smarter, stronger, and healthier. I know many people find my attitude offensive, but really, people, it is not in humanity's best long term interest to support or encourage the reproduction of serious genetic defects or low intelligence. Again, see my post The Purpose of Life.

A few other rambles:

Humanity is the ocean's most effective predator, and our fishing techniques are rapidly changing (evolving) fish to have less desirable characteristics. Fish are maturing younger and at smaller sizes as we select only the largest (previously most successful) fish. Fish that humans like to eat are being selected out - made extinct - versus undesirable, bony, badly tasting, or hard-to-capture fish. A tight school of fish may have worked to confuse dolphins or sharks, but it is an bright sonar target easily capture by our mile-wide nets today. And small and mid-size fish that avoid schooling behaviors make poor (unprofitable) targets.

Note that the world's most successful plants and animals are those whose evolution has made them desirable food for humans (cows, chickens, pigs, wheat, corn, rice, etc.). Then we help them thrive and reproduce, in numbers far exceeding natural populations.

Some people have argued against the use of windmills as a source of renewable electric power, based upon the fact that the turning windmills kill many birds. Tear down the windmills, drill for oil, save the birds. The reality is that more birds are killed by cars and trucks on the highway. (The activists would probably like to outlaw cars and trucks, too.)

I believe in the value of evolution: the birds that learn to avoid the rotating windmill blades will survive and reproduce. We can already see this effect along our highways: fifty years ago it was much more common to hit a bird on the highway, even though speeds were significantly lower then. Think of it as evolution in action (thank you, Larry Niven).

Last, the implications of evolution to a field near and dear to my heart: science fiction.

Contrary to nearly every movie alien, any intelligent life we meet in outer space will not be highly effective carnivorous killing machines. Au contraire, they will be (on their home planet) relatively weak and defenseless, needing superior intelligence to survive and reproduce. A dominant carnivore, or a herbivore that does not need to fear predation due to successful defenses (armor, size, quills, poisons) will cease to evolve. Every intelligent alien ever depicted with huge fangs, great strength, speed, armored skin, etc.,  is absurd, as they would never have evolved intelligence.

No, the most intelligent species will be those that are slow, weak, need protection from the elements, need to build and use tools to thrive, and need a civilization to defend against the superior strength, speed, and teeth of their planet's versions of lions, and tigers, and bears.

Of course, there is some evidence that intelligence is not a long term survival characteristic. We haven't yet met a single intelligent alien.

The Earth's Fragile Ecology

Most of my readers know that I'm fundamentally an optimist (see I am an optimist), and that I believe that science and technology (along with human ingenuity) can and will solve most (hopefully all) of our problems caused by technology and the resulting global population growth.

But it won't be easy, or cheap.

Most people seem unaware of the major ecological problems we face, focusing instead on a few relatively minor (but well publicized) potential problems such as Global Warming or loss of biodiversity.

Here are a few more for your consideration.

Loss of topsoil: Globally, current farming techniques results in topsoil being lost to erosion at rates far greater than natural replenishment. Topsoil (the only part of the Earth's regolith that can readily support crops) is being lost at a huge rate, resulting in reduced crop yields and even desertification in some areas. Currently, the recommended solution is to globally convert to no-till farming, which has the problem of requiring greatly increased use of herbicides and insecticides with their attendant and largely unknown long term effects.

Ocean anoxia: The huge influx of topsoil and fertilizer into the oceans is producing larger and more frequent dead zones, where nearly everything larger than a bacteria dies due to lack of oxygen. All of the nutrients lead to bacterial blooms which consume all free oxygen, and while some mobile fish can swim to the surface to gulp oxygenated water or swim out of the region, bottom dwellers and the myriad small critters that comprise the bulk of the food chain have no such ability. They die, and so do other life forms that depend upon them. This process happens to thousands of square miles every year, and the area and event duration is increasing.

Overfishing: The oceans are being depleted of desirable foodstocks are rates far greater than can be maintained. Already, many once common seafoods are becoming rare, and many fisheries are now effectively ocean deserts, completely devoid of large fish. At present, there are two approaches to solve the problem. One is to create huge "no fishing" zones to serve as replenishment stocks for the regions around them. This works in the short run (assuming enforcement by fast, armed ships), but eventually the fish will evolve to avoid fishing zones. The second solution is one that our leaders have done completely backwards. They have established minimum take sizes, where the fisherman is allowed to keep only fish above a certain size. Sounds good at first, as the young fish are allowed to live, feed, and grow. Unfortunately, there is something called evolution. Fish which once grew quickly to a large size (to avoid predation) are now evolving to grow more slowly and to reproduce at a much smaller size (avoiding predation by the most effective ocean predator, us). As a consequence, reproductive success is reduced, and the remaining fish are becoming less and less desirable. The solution? Capture (and eat) medium sized fish, encouraging these species to grow quickly to a large (safe) size and to produce large numbers of offspring to ensure that enough of them escape us to maintain their species. But this will take technology, and leadership.

Falling water tables: Everyone has heard of (or experienced) the relative and growing shortage of fresh water. Many people don't realize how serious the problem has become. Many cities (especially in desert areas but including many water-rich areas such as Orlando, Florida, USA) are pumping fresh water out of the ground at rates much greater than natural replenishment. Eventually the wells will run dry. Going deeper is often not a solution because of salt water, no water, or pollutants such as oil, lead, or arsenic. Along the oceans, pumping fresh water out of the ground encourages salt water incursion, a serious problem. One side effect of excessive ground water pumping is that springs dry up, and rivers that once ran to the ocean now shrivel and disappear. Water wars will result when cities / states / nations consume the fresh water that other downstream cities / states / nations need to survive.

Chemical pollution: To me, the most serious pollution issue is from the long term unanticipated side effects of biochemicals we create and dump into the environment. These include insecticides, herbicides, drugs, hormones, and especially antibiotics. We don't understand the long term effects of insecticides and herbicides; we ignore the possible unintended effects of long exposure to low doses of hormones and many other drugs (traces of which can be detected in many or most municipal water supplies), and we are rapidly breeding (thanks to evolution and the overuse of antibiotics) new bacteria (and likely viruses) which are immune to all known antibiotics. This alone could result in a plague which could destroy most human life.

The growth of cities: We tend to put cities (especially large, growing ones) at the worst possible places: in river valleys, along flatland floodplains, along the mouths of rivers. The same places that are the best possible farmland. We should build them on mountains, in deserts, rocky, hilly terrain, even floating on the oceans. Leave the good farmland to farming. Leave the river deltas for farming and allow the annual floods that replenish their topsoils and ecologies. Our cities continue to grow at alarming rates, covering the surrounding land with buildings and asphalt. And polluting or burying the former topsoil in the process.

Are there long term solutions? My favorite is to move humanity off of Planet Earth and into space habitats. See Colonizing the Solar System and Population Unlimited. Unfortunately, I expect that humanity will tend to continue to exploit the Earth in ever greater degree until the point is reached where most of the population will abruptly die. And then the survivors just might be smarter and do it right the next time. That, my friend, is evolution in action.

ECONOMICS 101

Some fundamental tenants, followed by discussion and ramifications:

1. There is no such thing as savings.
2. Money is not real (although it is a valuable accounting tool).
3. Prices are set by supply and demand.
4. Any attempt by people or governments to change any of the above is doomed to failure.

There is no such thing as savings, other than to store food or other supplies in a larder. We all live off of the current productivity of workers. For you to retire, you must convince someone else to work on your behalf (to provide you with food, clean water, sanitation,  energy, health services, everything you need). At the beginning of life, your parents did that. At one time, we would depend upon our children to provide for our old age. Investing in children was investing for retirement. But that time has past.

In today's society, we save for our retirement and therefore depend upon society to care for us. The only way that works is if:

1. We invest a portion of our current work productivity in infrastructure (capital) so that other, future, workers can be more productive. (In exchange, we expect those future workers to support us in the future via a fraction of their increased productivity.)
2. A large enough fraction of the population is working in primary production to provide for the non-workers.
3. The population dynamic is such that the future expected number of retirees is proportional to the future number of primary workers. This does not match reality!

Money is not real. Actually, money can be real, if it consists of coins or other valuable items (gold coins are real, as are gems and many other commonly recognized commodities). Paper money, or a coin whose value is based on a promise, is not real. Unfortunately, governments can print more money or stamp more coins. This dilutes the value of the existing currency, making it proportionally less valuable. Note that the total value of the good and services in the economy remains unchanged - only the number (accounting value) associated with the measurement of the economy increases.

The picture is not really so simple, but it will serve our purposes. The great thing about the concept of money is that it creates an accounting tool that allows us to share productivity, to allow a civilization to work together (some farmers, some miners, some builders, some engineers, etc.) where each of us can achieve greater productivity in a narrow field than any of us could if we each had to provide for all of our needs. Can a farmer build a house or a car? Can an engineer raise cattle and chickens for meat, milk, eggs? Yes, but not as well as a professional. And that, my friends, is the true source of wealth.

Prices are set by supply and demand. This is always true in the long run, although short term variation due to greed, fear, stupidity, and the delays needed to change production will happen. Capitalism works, for the most part, but it is slow to respond to changing markets. If oil prices jump, economic theory says that exploration, production, and distribution will increase supply to match (or exceed) demand. However, it takes years to find new sources of oil, drill the wells, build the distribution networks, the refineries, etc..

The government should have a role in pricing, to ensure fair competition, avoid fraud, and to make certain that the consumer fairly pays all costs associated with a commodity. For example, if a bottle of water is sold to the consumer, the price (manufacturing, distribution, and taxes) should reflect the total life cycle cost of that bottle of water, including the renewability of the water source (no dropping water tables stealing water from the future), and the disposition of the bottle (the cost of disposal or recycling - don't dump our current waste on our children).

Any attempt by people or governments to change any of the above is doomed to failure. History is full of failed attempts to control an economy. Price fixing invariably leads to shortages. Government attempts to define production invariably result in reduced choice and quality, with higher prices. Printing more money causes inflation. And since there is no such thing as savings, it is incredibly stupid to "invest" social security funds in government debt. All such debts must be repaid by taxes on future workers, whether you call them social security taxes or anything else. Who could come up with this concept? Unless the worker's funds are invested in things resulting in future productivity gains (which can include factories, research, infrastructure), this scheme is doomed to failure. Yes, I'm in favor of privatizing social security, just as I'm against the concept of government debt (except in the short term as a balancing mechanism). Unfortunately, it may be too late.

However, in our current economic environment I support government investment in real estate or other businesses (as well as research), because only then can we boost real worker productivity and escape the fragile house of cards we live in.

Threats to our Future

This post contains a list of what I consider to be the most serious threats to the future of humanity, as of today. It should be considered an incomplete and open-ended list; I'm certain that each of us can think of additional threats.

Note that I'm not considering threats to our civilization and/or way of life. There are many more of those. Rather, I want to limit this discussion to threats that can end all human life.

There are four main categories in two dimensions: the first dimension is simply natural disasters or man-made ones. The second dimension is things we can control versus things we can't. There may not be any entries in the list for "man made disasters we can't control", so perhaps we should qualify that as things we can't fix.

1) Natural Disasters we can't control/fix:

• Nearby supernova or gamma ray burst or passing black hole: Nothing we can do about any of these, so don't worry about them.
• Super Flare from the Sun: Our sun won't go nova or expand into a red giant for billions of years, but there is a possibility that it could have a major hiccup and blast the Earth with searing heat or sterilizing levels of radiation. Sea life would survive, as would any people lucky enough to be in submarines. It's too bad those tend to be men only; we also need women to save the species. Solution: co-ed submarine crews.
• Large Igneous Event: These have caused mass extinctions in the past, and might in the future. Not much we can do here, either, as long as we all live on the surface of the Earth.

2) Natural Disasters we can control/fix:

• Snowball Earth: At least twice in the Earth's history we have had global cooling so extreme that the oceans have completely frozen over, causing the loss of all surface life, and likely the loss of all oxygen. The solution is simple: Global Warming.
• Comet or Asteroid Impact: There are millions of comets and asteroids large enough to destroy all human life, possibly all life period on the face of the Earth. Some of these will eventually strike the Earth; this is inevitable unless we take active steps to prevent such a catastrophe. We may have years or millennia before the big one hits, but we may not have enough advance notice to do something about it, unless we start building the infrastructure now. We need a very well-funded Space Watch program to find these objects years before they might obliterate us, and given enough advance notice, current technologies are likely to prove sufficient to avert disaster.

3) Man-made disasters we can't control/fix: (these are things that we create, but have no effective control over, and no natural defenses against)

• Experiments gone wrong: While I'm a firm believer that nothing will go wrong when the LHC begins operation, I can't guarantee that all scientific experiments will have a similar result. If we knew the results in advance, we wouldn't need to perform the experiment now, would we? For example, if someone managed to create a nanometer-diameter black hole and drop it into the Earth, it would eat away at our planet and grow until it consumed the entire planet -- and there's not a damn thing we could do about it, even if we had hundreds or thousands of years before the disastrous end.

4) Man-made disasters we can control/fix.

• Nanotech gone bad: While it may be remotely possible to create a self-replicating nanite that will reproduce until all possible resources are consumed, burying humanity in 3 feet of gray goo,this is so difficult that I'm not worried about it. We can't create a reasonably self-powered machine that could live off of the environment at present. We cannot build a complex small machine that can self-replicate. Or even a big machine. In any case, this problem is well described, and guidelines exist to insure that any replicating machine will have limits built into it (such as a critical and rare raw material).
• Strong, malevolent AI (see The (likely coming) Technological Singularity) poses a very real threat, but one which may be difficult to realize, and one that we could choose to avoid by limiting computers to sub-human intelligence. Even if such an AI existed, there is a possibility of negotiation and co-existence so long as its intelligence and capabilities remain within the grasp of human understanding. But once we have made a machine significantly more intelligent than any human, we risk losing control. We will become the pets, to be neutered and/or put down at the convenience of the AI.
• Biotech Terrorism: To me, this is the thing to worry about. It is completely within the realm of possibilities that a small group, even an individual, could tailor a virus or bacterium to create an airborne disease of unparalleled lethality, one that was immune to our natural defenses, one that could wipe us all out. My friend Jeff Carlson has written an excellent  techno-thriller (Plague Year) about an engineered viral organism that kills nearly all warm-blooded life on Earth, and the most unbelievable part is that it was designed with a weakness that could be exploited such that we might survive. What if those designers had made a mistake and the self-destruct mechanism failed? Or the bug evolved and the mechanism failed due to a minor mutation?

Did you note the traditional really big things that I don't think threaten humanity?

• Nuclear War (and the threatened Nuclear Winter): Contrary to the hype we've all heard, we do not have enough nuclear weapons to destroy humanity, or even to create a nuclear winter. Many natural disasters release much more energy or release much more pollution. Yes, we do have the capability of destroying civilization as we know it, and even of killing more than 90% of humanity. But some of us will survive, live on, and rebuild civilization. An all-out nuclear war would merely set us back a few thousand years.
• Global Warming: Warming up the Earth by 5 or 10 degrees would eventually melt the ice caps, raise the oceans by 200+ feet, drown coastal cities, states, even entire nations. It would radically disrupt the ecology, and hundreds or thousands of species would face extinction. The expense of dealing with such a catastrophe greatly exceeds trillions of dollars. But in the big picture, this is an inconvenience, a forced change. Human casualties would be in the noise range, likely fewer than the toll from malaria.
• Overpopulation: Another serious problem, overpopulation has well-known natural controls: starvation and disease. Once half of everyone is dead, we no longer have a problem. Works for lemmings, too. The species survives. Note that the opposite problem, underpopulation, is much more serious (if it happens), because it is difficult to recover from the loss of genetic diversity. We'll lose some big cats (such as cheetahs) because they have insufficient genetic diversity to survive a nasty disease.

Please, propose your own threat to the future of humanity.

Capturing Apophis

Past blog posts of mine have described many aspects of the expansion of human civilization into space.

• Colonizing the Solar System
• Our First Colonies in Space
• Life in an Asteroid
• Population Unlimited (resource limits of comets)
• Our homes, the Comets
• Next Steps in Colonizing the Solar System
• Near-future Space Industries
• Animals in Space (both pets and food animals)

Today I'd like to focus on the orbital mechanics of capturing an asteroid, specifically 99942 Apophis (aka 2004 MN4).

Apophis is the near-earth asteroid that made the headlines in 2004 because of it's feared potential impact on Earth on Friday, April 13, 2029. Additional observations revealed that Apophis will miss by a hair (passing closer to earth than our geosynchronous satellites), but its orbit will be changed by that close approach such that there is a small chance of an Earth impact on April 15, 2036.

Apophis is a small asteroid, only about 300 meters in diameter (approximately 1,000 feet). This is too small to create an ELE (Extinction Level Event, to borrow a phrase from the movie Deep Impact), but it could devastate an area the size of Connecticut, or strike the ocean creating tsunamis that would kill millions of people and destroy trillions of dollars worth of property. Note that if we do nothing, Apophis will almost certainly strike the Earth some day, although perhaps not for thousands of years. We must take steps to prevent that catastrophe.

Luckily, one method of preventing a future Earth impact is to place the asteroid into Earth orbit, from which a future Earth impact is impossible. The near-Earth pass will result in a gravitational slingshot, changing its orbit.

As it passes near us in 2029, Apophis will be moving approximately 5 km/s slower than the Earth in its orbit around the sun, dropping in toward the orbit of Venus (and ignoring, for the moment, the additional speed it will gain dropping into our gravity well). If we do nothing, the near-miss will speed up Apophis by a few km/s, turning it from an Aten Asteroid (a near-Earth asteroid whose orbit is primarily inside of the Earth's) into an Apollo Asteroid (one whose orbit is close to the Earth's orbit, at least on average).

My own rough calculations indicate that if we speed up Apophis by a relatively small amount, such that it passes even closer to the Earth, then it will gain even more speed from its slingshot around our planet. A deflection into an orbit nearly co-circular with the Earth's will also speed it up to approximately Earth's orbital speed (a 5 km/s velocity increase is needed--well within the range of possibilities). Apophis only needs to reach closest approach about 500 seconds earlier than on the current orbit, still passing 10,000 kilometers above the Earth's surface.

It will have too much speed (due to the earth's gravity well) and will speed away (and outward), but will return to the vicinity of the Earth with a low enough speed that another slingshot around the moon will drop Apophis into Earth orbit. As a result of these two slingshot maneuvers, Apophis will have an orbit whose apogee is near the moon, and whose perigee (closest approach) can be tuned by small adjustments in its orbit before it performs the Lunar slingshot.

Over time, some additional velocity should be removed (by ion thrusters or other propulsion methods) so that its orbit is entirely within the moon's orbit, or some other permanently stable orbit. We don't want it crashing into the moon, either. Apophis is a far too valuable resource to waste.

I'm confident that the orbital changes needed to capture Apophis are within current technology capabilities, although more detailed analysis is certainly needed. And this is an opportunity that should not be missed: a billion dollar mission to capture Apophis will result in a trillion dollar resource in high-Earth orbit, and avoid a trillion dollar catastrophe at the same time.

Apophis masses perhaps 50,000,000 tons. While the largest percentage is oxygen, approximately 20% is metals (primarily iron). It contains large amounts of magnesium and aluminum, and significant quantities of hydrogen (think millions of tons of water). It contains more than enough silicon to build all of the power satellites we'll ever need.

Who could pass that up? If not NASA and the U.S. government, then perhaps the Chinese, or Dubai. Or even private enterprise; this project is well within the funding capabilities of large corporations or even a few individuals. Perhaps Bill Gates would like to have a private moon around the Earth. Or the Disney corporation (I'm thinking Disneymoon), or Hyatt Hotels (I'd love to stay at the Apophis Hyatt some day).

Any takers?

The Future of Sex

Yes, there will be sex in the future. You weren't worried about that, were you?

But will technology affect our enjoyment of sex? Will it be like in Demolition Man, where the sex act avoids physical contact and the exchange of body fluids? Or will it be like in (name the movie) where virtual sex is rampant and some people orgasm to death?

Sex toys are one area Moore's Law hasn't affected, but some day that will change in a huge way.

A realistic virtual reality simulation allowing people to experience sex with others (real or imagined) would be worth billions.

While porn would be the early adapter of "feelies", they would change the way all movies are made and presented.

What about virtual sex between virtual people? If our brains are uploaded into computers, I'll bet that someone figures out how to implement virtual sex that is largely indistinguishable from the real thing (at least to the participants).

Or is it truly the same? How will virtual self-representations affect virtual sex? Many people in gaming choose avatars not related to their physical appearance. That might be even more true when it comes to sex play. I'm sure that ED won't be an issue, nor will premature ejaculation. Or size. (Never mind. I was just told that size doesn't matter).

How about sex in space? In space, no one can hear you scream. (No, wrong movie.) In orbit or other zero-gravity environments, sex would be more difficult, a challenge. As I point out in Apophis 2029, while possible, sex in free-fall is awkward and likely tiring. It's still worth the effort, I'm sure, but it is different. Straps, hand-holds, and surfaces to thrust against would be important. Vital, even.

So, yes, I believe there will be sex in the future. Hopefully it will be between between consenting adults, and at least occasionally result in children. After all, if we stop having children (see The Purpose of Life), soon there would be no more sex in our future.

Animals in Space

In the long run, the animals whose populations grow will be those that either prove themselves valuable to humans or that prove hard to eliminate. In a resource-starved highly over-populated Earth, the choice of who survives--human or animal--is likely to be won by the human (ignoring the impact of sub-species such as attorneys).

The animals we take with us as our civilization expands into the cosmos are likely to be numerous. Those limited to a meager existence in zoos and parks can't be viewed as successful, but at least their lives will be in a rather pleasant captivity. Modern zoos are more like a Hyatt Regency than Alcatraz for their occupants.

Humans will likely keep our pets, the dogs and cats that provide us with love and companionship. Cats seem especially suited to a life in zero gravity--I have no problem imaging cats thriving in such an environment. Dogs, to me, seem to need gravity for happiness (running, jumping) but they'll adapt, I'm sure.

The other animals we take with us are those domesticated ones that taste good. We are, after all, omnivorous, and no amount of processing is likely to give an algae cake the taste and texture of a steak. I could be wrong, and there is a huge efficiency drop if we choose to eat animals instead of plants, but it seems that in a wealthy society, we'll find a way to raise cattle for meat and milk, chickens for meat and eggs, pigs for bacon and ham.

Better (more efficient) choices exist for meat animals; goats produce much more milk per pound of food consumed, rabbits much more meat. Chickens are quite efficient as-is. But you can't prepare a prime rib from rabbit. Still, these choices are likely to be early winners, in some cases because they eat different parts of the plant than we humans.

Seafood will likely be available, also. We already raise salmon, catfish, and other seafood in farms. These are likely to do quite well in space, at least as long as we can find and utilize large volumes of water (I like comets). We'll miss many foods from the top of the food chain (such as tuna, swordfish and the like), but varieties of others are likely to be plentiful, possibly even critters such as shrimp and lobster.

My question for today is, how many animals will succeed against our will (such as mice, or pigeons, or ants, or roaches)? Or what others must we bring along because they are a necessary part of the ecology? For example, must we use bees for pollination? Earthworms to churn the soil?

Here's a scary thought: What if there is some pest whose presence is necessary for long-term health, such as the mosquito? Some of them can't reproduce unless they've consumed human blood, but has any human ever reproduced before being bitten by a mosquito?