Our Man In Black

bot writes "A recent Slate article covers the onerous responsibilites of the Planetary Protection Officer. He is tasked with preventing contamination of earth by alien organisms, and 'forward contamination' (contamination of other planets with earth germs). There is also a published protocol (PDF link) for avoiding Martian bugs."

Comments

Re:Does NASA have too much money?

[the arbiter]

1. No, bathing probes in radiation is not enough to sterilize them, unfortunately. 2. NASA's planning on sending back samples from space and from the surface of Mars. Better have a protocol and procedure by then! Pay some now, pay much more later.

Re:Wildfire?

[hey!]

OK, IANAE but here goes.

The chance of an alien microbe getting a toehold on Earth is pretty much zero. Most every niche is filled by a lifeform that has four billion years worth of ancestors that didn't die before they breed.

Too optimistic, not based on actual experience.

Examples: fragmities, cane toad, zebra mussel, weird and untreatable hospital infections. West Nile Virus.

Actually, being highly tuned to a particular ecological niche doesn't protect an organism from anything but incremental changes in local fauna or flora. In point of fact, alien organisms (in the sense of from different ecological systems), if they can survive often end up growing explosively.

Why? pertty much everything in a mature ecology is food for something else. Animals on the top of the food chain are food for microbes. Usually microbes aren't a limiting factor in an undisturbed ecosystem because these animals also usually have evolved a conservative reproductive strategy: modest litters at infrequent places. WHich is what makes top level predators easy to endanger.

However, if you take an critter from the middle of the deck, or worse yet the bottom, their strategy tends to be predation limited or resource (therefore competition limited) or both, not reproductively limited. They are also limited by specific competitive defenses evolved by cohabitors of their particular niche. Which is why you don't see only one kind of critter or one kind of plant occupying a niche exclusively (which by your logic should be the norm), but usually there are many varieties predators, grazers, trees whatever, although one may be predominant. For example in the woods near my house there is both hickory and sumac, although they have overlapping niches.

The problem with an alien organism is that if it is naturally resource limited rather than reproductively limited, and has resoruces to exploit in its new home, there will be no factor checking its growth until it consumes all of the available resources.

I happen to work in the public health field, although I am not an epidemiolgist. We often remark that the unprecedently huge population of the human race is a microbe's bangquet. Space microbes do not concern me unduly, and the steps being taken by NASA seem prudent and sufficient. However we DO face potential threat from "alien" microbes that are released by ecological disruption. There are cases of permanent benign infections in remote populations that form a kind of symbiotic biological defense against incursion. Hanta virus definitely fits this pattern, it is possible the Ebola may as well.

The destruction particularly of tropical habitat, with its greater biodiversity and fiercer competition, is a public health concern. These places in past were avoided by humans because they were "pestilential". People who explored these regions often came down with infections, usually malaria but very often some unnamed agent. In addition to the loss of biolgical resource, the things that are released by these incursions, combined with rapid global travel, should be a serious concern. Ebola is, in a sense, too aggressive to be a global danger, but a bug like the 1918 influenza in its characteristics would be very dangerous indeed. Expect over the next decade a number of new stories about novel tropical infections, hopefully none spreading too far beyond their origin.

So, in short, from an ecological perspective your optimism is not warranted. Yes, the most likely situation is that a new bug will die out. However, if it doesn't die out it will very likely be a major problem, although not necessarily to human health.