Why don't trees catch a cold or why do we have a planetary protection officer?

parasites are finely tuned to their prey. things that devour are less choosy.

the main problem eaters will find is the chance they will find our ingredients differ in some way in terms of rotating carbon junctions that give rise the two forms for each such joint. so a protein chain in us will reisist his digestive enzymes due to bad lock-key fit problems, which enzymes need.

simple sugars/fats might be edible. but many of the protein building blocks will be useless and no cells will be built = no reproduction.

Of course, how does that help you if this large alien beast swallowed you whole and then dies....

Hey there a scifi movie for you. Some guy sneezes on a circuit board. Its offspring in in a couple thousand years come back to try to devastate the earth.

As far as trees and plants are concerned I think they have their own bugs and viruses. Just be glad that their DNA is far different from ours. We all ready have to continue with animal viruses mutating like the old Swine flu and now the Avian flu.

Just what we need is the corn flu.

You are absolutely correct about plants having plant-specific diseases, from parasites like root nematodes (can destroy whole fields of crops) to bacterial ailments, and viruses (such as the tobacco mosaic virus). Corn flu... That's not just trans-species, or trans-phylum, that's trans-kingdom. Highly unlikely it could happen, but if it did, don't be afraid - be VERY afraid! (Where's Orville Redenbacher, now when we need him most?!?)

We have blue tongue in the UK at the moment and this is distributed by midges, a small mozzi like creature.

Who is to say that the combination of drinking the blood of different guest animals, including humans, and the fact that they need to synthesise it to their food, will not ever be able to produce a cross over disease like blue tongue for humans? It happened with idiot diseases like mad cow which allegedly mutated into jacobs creuzfeld (my spelling may be out a few consonants but I cannot be bothered to check it however I am prepared to type this long sentence to explain my short coming) Do you think I have mad cows for people?

There are theories that reservoir animals (like the cows) and vector animals (like your 'mozzis' - sounds like what we call no-see-ums) can be breeding grounds for mutations, yes. Some viruses are capable of clipping partial strands of dna (google plasmids) and introducing them into a host's genome.

Mad cow for people? Probably not, but if you want some, here 'tis...

Hi case491,

most of our todays illnesses made it the way you mentioned!

Look at some book on the history of white man in the Americas, this is a history not only of arms and tools made from steel but more a history of illnesses brought with them and (fewer) illnesses brought back to Europe.

Most of these illnesses came from early people living close with their cows, goats, sheep, ... None of these illnesses were known to native American. So they had a hard time as the European people with the imported Syphilis. (Further reading in the book by Jared Diamond: Guns, Germs and Steel).

Also Malaria (the worst strain), AIDS, birds flu are crossovers from animals.

Mad cow disease is very likely to be very different.

So we will face -sooner or later- a next big epidemic that will threaten many lives, but how to prepare?

The European three waves of the medieval pest (14th century) killed at least 30% of the inhabitants.

RHABE

I know and that is therefor a big part of the reason why we have a PPO. Any organic compound, weather alive or not, could affect the way our organisms respond and interact with each other so we want to keep them separate until fully understood.

True - mad cow disease is thought to be spread by "prions" - more than a protein, less than a virus, barely meets the definition of "life", but possibly capable of wiping a species (including OURS!) out.

Check out those plasmids yet? Interesting stuff...

And to think WE created that bastard due to our GREED. Those humans seem not worth the benefit of life if you ask me. (if you can call them humans)

< Why don't trees catch a cold >

Maybe because they don't have noses?