I'm stranded on an alien planet. How can I tell what's good to eat?

Question

Survivor, Season 435 (teaser trailer): The holocamera pans over the night sky, revealing an utterly unfamiliar set of constellations. A blur, familiar to viewers, starts to disturb the seeming peace of the night, and the characteristic blueshifted hyperspatial portal soon opens up, with the latest round of contestants for the Holovid-show Survivor bravely (or hesitantly) stepping through.

The world is stable within the habitable zone, has bacterial, archea, as well as plant and animal life. O2 and CO2 levels are such that the air is breathable (although a nasal filter might be a good idea). H2O can be tapped or gathered. The life-forms share Earth's DNA, left-handed basic structures, but have evolved under their own constraints and random events. No (known) ascended dolphin-level or above intelligent life has ever been found anywhere else in the Universe but Earth.

There are 150 contestants, distributed in groups of 30 at positions AI-weighted to be equally-(un)-favorable for Earth people. None are allowed any foreknowledge of the conditions on the world, besides likely temperature range. AI sentinels and force-casts are in place and will prevent potentially lethal dangers from engaging the Survivors before they get a chance to dig in a bit. Each contestant is allowed as many supplies as a light exoskeleton can carry (~ 200 kg net weight), although no recharge cells are provided for the exos. Allowed food supplies are capped at 60 days standard rations. No seeds, animals or any other non-vital symbionts are allowed through the decontamination filter.

Groups have a chance to tap out once every 604,800 standard seconds (one Earth week), in which case any survivors are rescued and eliminated from the game. Complete loss of all members will (naturally) also automatically eliminate a team. Last team left wins. If at the end of 53 rescue opportunities more than 1 team remains with living members on the planet, the number and strength of the health signals of the survivors are assessed and a winning group is declared. As per the standard Survivor contract, the winners get full land and mineral rights over the new world.

What is a good, potentially winning strategy of ensuring a food supply, in terms of adapting to identify and use edible variants of the local plant and animal life?

Answer 1

What plants to eat and what to leave?

Better use the UNIVERSAL EDIBILITY TEST:

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1. Test only one part of a potential food plant at a time.

2. Separate the plants into its basic components — leaves, stems, roots, buds, and flowers.

3. Smell the food for strong or acid odors. Remember, smell alone does not indicate a plant is edible or inedible.

4. Do not eat for 8 hours before starting the test.

5. During the 8 hours you abstain from eating, test for contact poisoning by placing a piece of the plant part you are testing on the inside of your elbow or wrist. Usually 15 minutes is enough time to allow for a reaction

6. During the test period, take nothing by mouth except purified water and the plant part you are testing.

7. Select a small portion of a single part and prepare it the way you plan to eat it.

8. Before placing the prepared plant part in your mouth, touch a small portion (a pinch) to the outer surface of your lip to test for burning or itching.

9. If after 3 minutes there is no reaction on your lip, place the plant part on your tongue, holding it there for 15 minutes.

10. If there is no reaction, thoroughly chew a pinch and hold it in your mouth for 15 minutes. Do not swallow.

11. If no burning, itching, numbing stinging, or other irritation occurs during the 15 minutes, swallow the food.

12. Wait 8 hours. If any ill effects occur during this period, induce vomiting and drink a lot of water.

13. If no ill effects occur, eat 0.25 cup of the same plant part prepared the same way. Wait another 8 hours. If no ill effects occur, the plant part as prepared is safe for eating.

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CAUTION

Test all parts of the plant for edibility, as some plants have both edible and inedible parts. Do not assume that a part that proved edible when cooked is also edible when raw. Test the part raw to ensure edibility before eating raw. The same part or plant may produce varying reactions in different individuals.

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How to catch animals?

Plants you can just pick. In order to eat animal life, you first have to catch it. Traps made of rope and wood should crush, choke, hang, or entangle the prey. On earth small mammals as well as birds, insects, worms and crustaceans are your best bet to trap or gather. Try to find alike beasties and again apply the edibility test.

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References:
http://doomguide.com/sas/pages/ch09.html
http://doomguide.com/sas/pages/ch08.html

Answer 2

Note: none of these methods are foolproof. Try a little of anything you eat before eating a lot of it.

Plants

Avoid leaves and stems.

It seems that these are not only typically inedible in general, but there is a laundry list of plants whose have roots or fruits that are edible, but with toxic stems and leaves. This is because generally they want to attract animals to eat the 'berries,' but not themselves. Also, plants may tend to want their seeds spread, but not their 'bodies' eaten, so the toxins would be in the leaves and stems. Of course, this is a huge generalization.

Watch what the native animals eat.

This is not fool-proof. But if you watch the berries, fruits, and vegetables (and others?) that a variety of animals can consume, these would be likely to be more viable to your palette.

Roots and Legumes

These have less likeliness (although not always) to be spotted by birds and large mammals, and therefore have not needed to develop a poisonous defense against them. Obviously some animals do root, so be careful, but there is less defensive interaction between them and animals in general.

On your island or whatever, the tropical plants might be good anti-biotics, because they don't have a frost to kill off some bacteria seasonally. This holds a good medicinal purpose.

Plants with other defenses

If you think of a bright berry, versus a highly placed, well-shelled fruit (say a coconut), the defense of the berry might need to be poisonous as they're largely vulnerable. Again, I say this is just as advice, as obviously you can eat a strawberry.

Animals

"Swarms and Herds"

Think of a school of fast, small fish versus a wandering stonefish. The former survives natural selection by having a large number of offspring to ensure that some will survive, while the latter survives largely by being toxic.

'Mammal' 'Milk'

IF (if) you have animals that produce drinkable nutrition for their offspring, it's a safe bet that you can 'milk' the animal for nutrition. In many cases it can be high in calories, and easily digested since it is for their young. So go milk an alien cow (good luck).

Watch what the other animals eat

(see above in plants)

Select the right parts to eat

On Earth, muscle and fat (although not always) isn't carrying as much blood and waste as it is nutrition. Avoid, in general, the organs, and go for the muscle and fat.

Other

Variety

In order to ensure you get the right nutrition, try a wide variety of foods.

Insidious

Select the weakest link and have them do the taste-testing. Keep cycling through testers until you've found something you can eat. You'd probably only lose one or two unlucky ones.

EDIT AS REQUESTED: Fungi, lichens, mold

Fungi

Your best bet with fungi is to cook it. There are many Earth fungi that are edible, and very few that are toxic (and even then, you must ingest many in order for it to really kick you). The conditionally edible fungi appear to be fine if they are cooked.

Lichens

I would stay away from these as they are a symbiotic system, so you don't know what else you are getting. In Earth's case, there are very few that are edible, but the most popular is Iceland moss. Maybe a rule of thumb is, "if it looks like lettuce, it might be edible..." ha

Mold

Uh.. I guess you could use mold to culture animal products and make cheeses?

Answer 3

In addition to the other answers here, I would like to stress the importance of cooking.

Lifeforms produce poison to protect themselves. Often, poison is made of proteins, because proteins are easily able to react with cells. Cooking degenerates proteins, meaning that the poison will lose its function. Indeed if you cook most poisons, they are likely to become harmless [citation needed].

At the same time, it is unlikely that cooking will produce new poisonous material. [source: biochemical student] This could happen if the cooking process splits up complexes which are comprised of poisonous parts.

Still note, that in general, there is no way to tell if food can be eaten. For instance, we cannot even tell if an unknown (earthly) mushroom is edible. I was merely pointing out a way to slightly reduce the danger.

Answer 4

Something has to cause evolution all over the galaxy to follow almost exactly the same pattern that it did here on earth, i.e. the universal blueprint for life has to have a lot more in common than just DNA. Six essential amino acids have to be available, to start with. Various vitamins. Compatible sugars and starches. Ascorbic acid (Vitamin C) is pretty much a universal in Terran plantlife, but elsewhere? Conversely, nothing horribly toxic to humans as a universal in the alien planetwide biochemistry.

On top of that, our bacteria and other-world bacteria have to be compatible. That's a tall order. I'd expect that our bacteria would reduce all life on another world to stinking slime, or that bacteria on an alien world would reduce humans to stinking slime, or both of these together followed by a billion-year struggle between two clades of bacteria for supremacy or symbiosis. If our bacteria can't digest other-world life and vice versa, I think it unlikely that us humans could digest the same life.

I think all this unlikely, but for this scenario it has to be true. Panspermia might account for it, or "ancient ones" spreading earth-equivalent life across the galaxy in relatively recent geological time, and then transcending the physical. Ok, suspend disbelief ....

You can easily survive two weeks without food, so don't rush. That universal edibility test would do well to start with eating one gram then three grams, ten grams, ... not jump straight from a tiny sample to a quarter-cup (30 grams? )

Also identify something sweet. If no plantlife on this planet offers human-compatible sugar, the best (only? ) hope would be eating animals. Starches, if digestible, turn sweet in your mouth if you chew on them for long enough (amylase in saliva breaks the starch down into sugars).

Also if you home in on a fruit, make sure that there is plenty of it in a less-mature form. It would be a shame to discover that "apples" were safe to eat in "November", when there won't be any more for nine months. Even worse with "raspberries" (they keep less well). Roots are more likely to poison you but far less likely to go out of season.

Obviously as a team, each team member should be guinea-pig for a different potential food source.

On earth you are far less likely to be poisoned by eating animals than plants, because the biochemistry of animals has far more in common with that of humans than the biochemistry of plants. On an alien world, this might not be true, but given the prerequisite setup above, it is plausible. The problem with a wholly carnivorous diet, is that you eventually run into deficiency diseases. But you would gain time to analyze which plants are least toxic, if finding a highly edible one proves difficult, and you might not need much plant intake to supply the missing trace nutrients.

Answer 5

• Bring silver utensils. Silver reacts with arsenic and some sulfides, meaning the utensils themselves can, with enough exposure, double as make-shift indicators of stuff you can't eat. Silver utensils also self-sterilize over time - double trouble!

• In addition to Bookeater's answer, plants with a white-ish sap is potentially more risky. Proceed with extra caution if you want/have to test plants with white or white-ish sap.

• Additionally, again in reference to the guide provided by Bookeater, when you have progressed to oral tests, be on the lookout for bitterness. A very bitter taste is a good indicator of poison.

• Look out for rash, mold, spores, fungi, etc. on the plants! Never eat a plant that looks like it might be infected or under attack by another organism.

• Avoid mushrooms, reptiles and marine life.

• Any insect that is not brightly-colored or slow-moving should be fair game, but watch for sacs that contain eggs or liquids, and do apply the edibility test before ingestion. Cook prior if possible/feasible.

• Any otherwise healthy-looking mammal that is properly gutted and bled, and carefully examined for the ability to poison its prey (while a Komodo dragon might be safe to eat for all I know, but I don't know if I would risk it - you never know if you have contaminated otherwise safe meat on accident during the slaughter), will most likely have meat that is safe to eat after treating with heat.

• ...or you can cheat and bring chemical tests. There is a wide variety of liquids and compact filters that will color-react with given compounds. If 30 people can carry 200kg each of supplies, even when you factor in rations, tools, shelter, etc., you have more than plenty room for vials of dye, one-off tests and similar. You could probably test hundreds if not thousands of foodstuffs without ever putting yourself in harm's way.

Answer 6

Take a tricorder (or any other technical means to analyse the composition of the plants for edibility) with you, and use that to identify edible plants.

Other than that, your only chance it to try a bit of it and check whether you get sick. If strongly poisonous plants are common, you'll probably lose a few team members, but without testing equipment, I don't see a way around it.

Obviously every new food should at first be eaten only by one team member, and only in a small amount so there's a good chance for the taster to survive even if it turns out to be poisonous. If no bad effects are seen, the taster should eat increasing amounts, until either symptoms arise, or you can reasonably assume that this food is safe.

Of course as soon as you've identified enough edible stuff for survival, you stick to it. No point in risking lives by testing yet another plant for edibility.

Answer 7

I have no way to verify the following claim:

Applied Kinesthesiologists maintain that muscle testing can identify whether a substance is beneficial, or toxic. If this is true, having one or two members of this specialty in the group would be quite an asset.

Essentially what the AK practitioner does, is have a person taste a small quantity of a substance, while laying flat on their back with an arm held straight up. With the instruction to resist the AK from trying to move the arm, both before and after tasting the sample, he can tell whether the tested item is beneficial, neutral, or toxic, by comparing the relative strength of muscular reaction. If the test subject suddenly becomes weaker, and is unable to resist moving their arm as directed; then the conclusion is the sample is toxic.

see ref http://www.encyclopedia.com/medicine/divisions-diagnostics-and-procedures/medicine/applied-kinesiology