We Will Destroy Your Planet (15 page)

Some fly, some crawl, some are terrifying to humans, while others are merely repulsive. The insects are, however, essentially the unseen below-stairs staff of the Earth's biosphere, performing vital tasks in both recycling dead and decaying materials, and ensuring the spread of plant life by pollination.

Fish are aquatic animals adapted to filtering oxygen from water by means of gills that allow oxygen molecules to be absorbed into the bloodstream by osmosis. There are many species of many sizes, not with manipulative limbs. Most species are used as a food source, particularly by humanity.

There are predator species of fish in various sizes, from small piranhas to the huge great white sharks, which are capable of consuming humans and even of damaging waterborne vehicles. These creatures should be avoided.

The oceans are also home to cephalopods, tentacled creatures with multiple brains and hearts, quite unlike anything else on the planet. Some of these cephalopods are large enough and powerful enough to – according to local legend, anyway – attack and sink surface vessels such as boats and shipping. In fact the most alien creatures, compared to the standards of the human population, live in Earth's waters, including strange single-celled creatures that congregate around lava vents in the deepest high-pressure areas, and life forms which are neither truly animal nor vegetable, but somewhere in between. Perhaps even with a bit of mineral thrown in to complete the traditional set of organic elements.

Birds are the Earth's avian species, and in fact are direct descendants of the prior dominant species of the planet, the dinosaurs.

There are both flighted and flightless species of birds, and even a few aquatic species which ‘fly' only underwater. This latter tendency should not be a surprise, as it is still movement in a full three dimensions, which relies on planed limbs for manoeuvring.

Birds should be no threat to an invading culture. As well as being a potential food source themselves, birds also are an egg-laying life form, rather than giving live birth, and the infertile eggs are a common food source on Earth.

Unlike the other animals on the planet, reptiles are cold-blooded, with a much lower body temperature and no internal means of regulating that temperature. They too are egg-laying creatures.

Some of the reptile species – in particular the crocodilians – have been around since the time of the dinosaurs, which had led most humans to believe that the dinosaurs were themselves reptilian. However, it has subsequently been discovered that those dinosaur species that were not made extinct at the K/T impact later evolved into birds. This suggests that the other dinosaurs were, like birds, warmblooded, and thus not reptiles. That would mean that the reptiles were always cold-blooded.

Since reptiles have been around on Earth for hundreds of millions of years in a relatively unchanged form, some believe this is a sign that aliens such as those of you now invading the Earth could quite likely be reptilian in form, if the pattern of reptile evolution is a universal norm, and there was no K/T impact on a reptile planet.

Of course, if your species is itself a form of reptilian or dinosaur life having travelled forward in time from before the K/T impact, you will already know about these species. Many humans consider reptiles to be frightening or unsettling, and this may be worth taking advantage of.

There are only 5000 mammalian species, but they are the ones that you will be most concerned with while living on Earth. The most notable mammal species is, of course, the dominant humanity, but there are many other species sharing the planet with them.

Mammals come in many different sizes, and vary between two and four-legged species. Some have been specifically husbanded by humanity as food sources – cows and pigs, for example – while others such as sheep are bred for their outer coating. There are many large predator species of mammal, but also small scavengers and rodents. Not all mammal species live on land: dolphins, seals and whales are mammals despite being aquatic.

Although the human species considers itself the dominant intelligent species on the planet, it is neither the only intelligent species nor the only one that could pose a threat to your plans for the world. Taking these issues in order, the first thing you must bear in mind is the existence of other species who may be at least as intelligent, but who simply have not evolved the physical capability to mechanically affect their environment.

On land, the apes are the closest species, genetically, to humanity, and so they naturally are close in intelligence also. There are some gorillas which have been taught to communicate with humans, and also various of the ape species are adept at using tools, and have complex social interactions, as do humans. The elephant, the largest land mammal, is also very intelligent, and has been known to display both mathematical skills and artistic talents.

In the oceans, the dolphin species is thought by local scientists to be as intelligent as humans, if not more so. They are famous for displaying empathy with not just others of their own species, but with other species that venture into the water as well. While these aquatic species are intelligent, they are unlikely to pose much of a threat to you. Even if they become hostile, they do not have the means to use weapons.

The type of threat that you will face from various other life forms on Earth is going to be in the form of attacks from predator species, and also from defensive strikes from venomous reptile and insect species.

Predator attacks are going to be the most effective, and the ones that you must guard against. The claws and fangs of the various large predators on Earth will be equally effective against any form of organic tissue, regardless of its planet of origin.

If your species is small in size – say less than one or two feet in height or length – you may find that insect and reptile species attempt to prey upon you, with the use of chemical venoms meant to paralyse or kill. If you are larger, you may still trigger defensive or territorial attacks from these kinds of creatures, even if they are not motivated by viewing you as prey.

Whether the venom from such creatures will affect you, or do so in the same way as it would affect native terrestrial creatures, is impossible to determine without study. You should certainly obtain samples for testing, and to produce antivenom if necessary.

Disease, germs, virii and bacteria are actually much more likely to be a problem if you have come from a parallel world or different time zone on the Earth itself, than if you have from a different planet elsewhere in the galaxy.

The reasons for this are due to the way that such biological agents evolve, and the way in which resistance to them works. Specifically, while some exposure to bacteria and virii can trigger the immune system to recognize them and build resistance to that strain, so the absence of exposure over generations will result in that immunity or resistance being lost, as the human DNA mutates. Also, the viral life forms themselves will also mutate in attempts to out-evolve both resistance and drug treatments.

The practical upshot of this is that if you come back in time from a future Earth, you will find that biological threats in the target era are adapted to affect humans of that era, but any such bio-agents which have been eliminated between the target era and your own will be
more
dangerous. With those bio-agents no longer a threat in your era, you will almost certainly have lost your resistance to them, which local humans will have due to exposure. The bio-agents, however, will more likely still be perfectly adapted to you, being human, and thus their effect will be more devastating upon your forces than upon the more resistant humans native to the target era.

Conversely, new diseases and bacteria will have evolved in your era, which are capable of affecting the people of the target era. You must be careful not to carry these back in time to the target era, as not only will they be effective against a population which has no resistance to them yet, but you will risk causing a paradox in which a pathogen from your era wipes out your own ancestors.

There is a similar danger of cross-contamination for those invaders coming from parallel worlds, though at least in their case there is no need to worry about the potential for temporal paradox.

Those of you coming to Earth from other planets will doubtless also bring assorted bacteria with you. It is believed that bacteria are capable of surviving in dormant form in space, living on asteroids and surviving meteoric impact with the Earth's surface. In fact, the theory of panspermia suggests that microbial life is capable of originating from base chemical compounds and amino acids almost anywhere, and that comet and meteor impacts may have brought it – or at least some forms of microbial life – to Earth in both the past and the present.

This means there is already good reason to believe that alien bacteria could thrive on Earth, building its way up into life from the simplest chemical compounds. But what about the other way round?

Most people on Earth believe that the Martian invaders of whom H. G. Wells did such a good job of reporting in
War of the Worlds
were wiped out by native virii – specifically the common cold (a viral infection affecting the respiratory system and eyes). The popular belief is that the Martians are killed by their lack of immunity to this virus, and that therefore germ warfare would be a practical option for defending against future invasions. However, this is not actually the case.

Examining the original text shows that what attacks the Martians are in fact necrotic bacteria – the bacteria that decompose the flesh of deceased organisms. This occurs because the Martians are not recognized by terrestrial bacteria as alive, and therefore are treated as dead, and disassembled on a cellular level. They are in fact decomposed to death.

Thankfully, this is actually an unlikely event to happen to you, though it does happen even to humans, in the form of necrotizing fasciitis.

The good news is that you will probably not – if you come through space from a different planet – have to worry too much about virii, because they have spent millions of years evolving and adapting to affect terrestrial species. This is, after all, how they best survive. In fact, humanity – and the other species living on Earth – would have more to worry about from the bacteria you bring, as those bacteria are more likely to be robust basic bacteria, ready to adapt themselves to new environments and life forms, as happens in the previously-mentioned panspermia theory.

When it comes to food, it is said that there cannot be a creature on the planet that the humans do not cook and eat. If any of the foodstuffs on the planet are suitable for you, then that is an excellent advantage. If you are trying to pass as human, though, take care not to be seen eating anything that the local culture considers repulsive – such as live rodents – as this will arouse suspicion.

Discovering a food source on Earth is a task not to be undertaken lightly. It will be of vital importance, and it will also bring with it certain implications that are not at first obvious.

It is utterly vital that you test every type of organism on the planet – from the smallest bacterium to the largest cetacean – with which you are likely to come into contact. You will need to know whether any of them are pathogenic to you, and you will need to know which, if any, of them are capable of providing your species with nourishment. You will also need to know if any organism is likely to have an unexpected non-fatal effect on your forces, such as causing allergic reactions, dizziness, sensory interference, neurochemical imbalances, drunkenness, or whatever.

If your tests identify any organic material as being digestible by your species, and that your bodies will absorb nutrients from, this is not all good news. On the one hand, it does mean you do not need to import all your food supplies from home, but the cloud to that silver lining is that it means bacteria which can affect those organisms can be absorbed by you, and could kill you.

There is no reason not to use other life forms – native terrestrial ones or extraterrestrial – as helpers, or even as weapons. The concept is older even than sentient life on Earth, as mutually co-operative arrangements have lasted a long time. Obviously humans have domesticated many creatures, such as horses for transport, dogs as guards, etc, but other creatures across the planet have done it too. For example there are birds that certain large predators such as crocodilians allow to clean their teeth for them; there are remoras, which protect sharks from parasites; and many other such relationships.

You may find, therefore, that it is useful to either recruit certain humans to perform menial duties, or, if humans are simply too rebellious and unreliable, you can always train other creatures for certain duties. Aggressive predators, for example, can be trained to patrol important exclusion zones and attack intruders. Other territorial animals can be conditioned likewise, or equipped with cameras and sensors to increase security without requiring the use of more of your forces.