# Impact of living on a world with no terrestrial fauna

Assume Humanity was really wrecked by some malignant force, and a group managed to escape and find a habitable planet and 'settle' it. They weren't able to bring along much in the way of advanced technology, but they were able to bring along relevant knowledge. So, while they reverted to the 'Middle Ages' as far as basic technology goes, they can take care of things like medicine and nutrition much better. They're then able to, over time, re-build up to a WWII/1950s era technology level.

The world they found is very early in its development cycle. There's plenty of fish in the sea, but no creatures have made their way onto land yet.

Clarifications & Updates The planet is assumed to have plant life (Otherwise it is far too uninhabitable even if technically livable). It is noted below that trees developed much later, so I am curious as to what could replace them (even if it is handwaving trees into existance).

Initial population size is a few dozen thousand - perhaps 40 to 75. They arrived in a small fleet of vessels, with small craft for planetary transportation. There is no method of refueling these craft, and the large craft are too large to land. I am presuming they can use these ships for a few dozen years to set things up. The craft have some manufacturing capabilities (IE, printing books), but were not designed or supplied for a long term mission. They function long enough to establish a foothold, gather some images for maps, do some limited surveys, etc.

What sort of impact would this have on a (re-)developing civilization? From what I've read and seen, there would still be things like coal and oil (Although in lower quantities), but beyond that I have no idea on what sort of repercussions there would be for civilization.

• did they forget to bring pets along? – user6760 Sep 8 '17 at 6:02
• Some of the points made in World without oil? what is the quick replacement? and Is there a way to have coal but not oil? and A post-apocalyptic industrial revolution, while none of those apply directly to the question you are asking, may still be of interest. – a CVn Sep 8 '17 at 7:40
• Ceteris Paribus compared to earth? You can easily just research people that mostly ate fish like people in the middle ages ... I think the biggest downsides might be the primitive fauna and not the lack of animals, so it is important to know what you have there. – Raditz_35 Sep 8 '17 at 8:08
• PLEASE EDIT THIS QUESTION: You say no creatures have made it to land. Does the land have plants? forests? bushes? Grass? I understand no insects or fish on land; but on earth, the bottom of the sea food chain is autotrophs [ en.wikipedia.org/wiki/Autotroph ], photosynthesizing plankton and mosses, algae, and larger plants like seaweed and hundreds of other species. Landing on a bare rock, even with an atmosphere and oxygen, is a recipe for a quick death. – Amadeus Sep 8 '17 at 9:58
• One other problem is that they may not be able to eat the local plants. Or, almost worse, they can eat them but the local plants lack one or more of the nutrients that we need to be healthy. People could start getting sick and weaker without knowing why. – ShadoCat Sep 8 '17 at 23:09

Assuming they have been there for some time, slavery would prevail, humans would take the place of draught animals for labour etc,. This has played out enough times in different parts of our World's history in both large and small economies without suitable animals for labouring purposes. Inca and the Pacific Islands spring to mind, but pretty much everywhere at some time or other.

Important things to everyday life would be problematic, leather, sinew, bone etc,. there is an obvious source but it would make a distasteful story. Probably large economies would all be coastal and industry and some technology would be based on sea life.

Living inland would be a big problem, nothing produced that would be worth trading such as skins or furs, so marginalised communities would inhabit the inland areas. With perhaps some specialised communities engaged in mining ores or something similar.

# Pessimistic Scenario

I am going to be pessimistic and suggest that your colonists will die unless their new home is very much Earth-like and much closer to our geological timeline than you suggest.

It seems that your world is akin to Earth of the Cambrian period (541–485.4 mln years ago) since you say that land is still uninhabited. And it creates a huge number of problems that cannot be solved with Medieval technologies.

## Food Production

'No land creatures' does not mean 'no life'. But it suggests that there are no higher plants. Most likely you have lichens and bacterial mats. These are good for oxygen, but not so good for the soil. There is some research suggesting that plant life developed much earlier than the Cambrian period, about 700-1300 mln years ago. Still, it took a long time for soils to emerge. They also require the presence of incests, worms, and other animal life. The first soils similar to ours developed only about 350 mln years ago after the land was filled with all kinds of animals. Grasslands did not appear till 65 mln years ago.

Even if you manage to bring seeds, you will not be able to grow crops. Available soils are unable to support root systems and do not have nutrients required for contemporary crop plants.

## Building Materials

No soils supporting higher plants also results in absence of building materials. Thorne mentioned timber, but you might not have even ferns and mosses. So, you will be restricted to mud, clay, and stone. Building even a simple shelter will be a big undertaking.

## Tools

Civilisation and technology mean tools. While your colonists will be able to scavenge and repurpose something from a ship, they need to be able to produce their own tools. Unfortunately, the Cambrian setup limits them to stone. Moreover, it is not even possible to produce a simple axe: there are no handles.

Metal and bone are not an option since you cannot smelt ores and forge metals and vertebrates with suitable bones do not exist.

## Mobile Power Sources

Animals are not so good sources of food (need too much food to grow or too hard to hunt), but they are delicious and most importantly they are great for powering your technology. If humans are the only animals available as power sources the productivity is very low and specialisation necessary for a successful civilisation building is hardly possible.

## Fuels

### Oil

Good news -- oil will be in a process of creation. Bad news -- you, probably, have to wait several dozens of millions of years before it is usable.

### Coal

You might luck out and find a little bit of coal formed from ancient algae. But most of the coal originates from flooded forest and your planet is not there yet.

### Natural Gas

You might get luckier with natural gas, especially if at least some part of it is not biogenic in origin.

### Biofuels

Algae fuel is your best bet. Your planet is exceptionally good at nurturing all kinds of algae. BUT you most likely need an industrial level of technology to extract fuel from biomass.

## Biology

There is no guarantee whatsoever that the planet is habitable without terraforming. While building blocks of life might be the same they are not necessarily arranged in the exactly terrestrial way.

We tend to think of ourselves as highly adaptable species. And this is quite true but in Earth conditions. The problem is that parameters of our survivability are very narrow. Slight differences in temperatures, atmosphere composition, and humidity may render a planet unlivable without advanced technologies and life-support systems.

When it comes to food sources the situation is even worse. Humans might be unable to digest local food. They might be allergic to local flora and fauna. Plants and animals may accumulate toxic quantities of some substances.

There is also no guarantee that terrestrial plants and animals will survive. Modern crops are very vulnerable. You will unlikely to have pests unless some algae and fungi decide they like to chew on your wheat, but weather and soil conditions might turn to be very unfavourable. Lack of nutrients, strange weather patterns, flooding or droughts... just one of them is enough to put your settlement to the brink of extinction due to crop failure. Similar reasoning goes for animal husbandry...

I am sure there are more possible reasons for the colony to fail. But even this is enough. Let's move to Paradise.

# Optimistic Version

Your colonists are extremely lucky and end up on Earth 2.0. The soil is good, the marine life is digestible, and terrestrial immune systems are dealing with the local environment just fine.

We will also assume that the climate is nice: not too warm, not too cold; the winters are mild and short; there are no hurricanes, tornadoes, or typhoons. Something like a Mediterranean climate on Earth. You will have a long growing season suitable for many agricultural plants. You also will not need to invent and erect architectural marvels to protect from elements.

I hope I am close enough to an Eden world. But even Paradises have problems.

You will have exactly the same problems with power, building materials, and tools as in a pessimistic scenario. So, there is a high probability that your colonists go back to stone age agriculture and fishing instead of rebuilding civilisation.

Even if your colonists brought enough tools and specialists to jump-start a Medieval-type community and make it sustainable, including the production of necessary tools, animals, foodstuffs, textiles, and so on, it does not guarantee quick technological progress.

## Population Size

The more advanced your civilisation, the more people you need to support it. The only exception is fully robotized society. So, you need some minimum population to start and a high population increase to progress technologically fast (given that you already have a technology chart).

A rather small Medieval town had a population of about 10 000 people. This allows for a self-sustainable community given that all raw materials can be gathered nearby. Big cities had populations of hundreds of thousands people. Check this link for some other interesting facts.

In 1950, USA population was about 150 mln people. The economy was virtually self-sustainable. There is an evidence that agriculture was over productive, but it helped to absorb the shock of the 1950s Drought. At the time the USA was also a world leader in terms of science and technology. So, I suppose, it is a good point of reference.

So, your problem is to progress from 10 000 people to dozens of millions in the shortest time possible. Time is important here due to problems associated with knowledge.

## Knowledge

Bringing knowledge and keeping it through generations is not the same thing.

### Medium

If your colonists do not have hard copies of their knowledge and cannot establish an effective educational system the majority of information will be lost.

Your colonists have to store knowledge in some form that is accessible to their Medieval level descendants but in volumes useful for higher technological levels. You do not want them to reinvent electricity and bicycles. You want them to build from blueprints ASAP.

Stone tablets are known to be one of the most reliable methods of information storage. But they are heavy and take too much space if you want to fit a couple of contemporary textbooks. You might want something like paper vellum.

For newly accumulated knowledge your colonists will need a way to write it down. Unfortunately, stone and sun-baked clay tablets can be the only available to them media (the tree problem strikes again).

### Preservation and Passing onto Next Generations

10 000 people seem like a lot of people but their cumulative knowledge is smaller than knowledge available in the 1950s. Moreover, much of what they know is completely irrelevant to their current situation. In addition, without an extensive educational and knowledge systems that we have now (or even in the 1950s) passing this knowledge onto descendants would be problematic. And of course, the first planet-born generation will be more interested in learning how to farm than a theory of aircraft building (no resources to build one).

There is nothing can be done about resulting loss of immediately accessible knowledge. However, if you establish compulsory school education, keep 100% literacy, encourage scholarship, and preserve scientific method and germ theory, you might significantly shorten your Dark Ages. Do not forget to establish some kind of a scientific council and give them THE Civilisation Development Plan. Too bad it is hard to combine with religion... but if you can, you could promise eternal punishment to those heretics who refuse to learn professions necessary for fulfilling The Plan.

## Other Things

You can expect a loss of purpose, mutinies, riots, peasant riots, famines, pandemics, etc. The lower your population the more risks all those pose.

It is also possible that your colony will start a global climate change by bringing invasive plants. They will suck too much CO2 from the atmosphere and trigger an ice age... If it is the case start polluting ASAP.

## More Other Things

The first generation will go through 'survival syndrome' and PTSD. Just it makes a great story.

• I've just finished reading a delightful book (Anathem by Neal Stephenson) that described a monastic system built around what amounts to rigorous philosophy. The book is a work of speculative fiction located in a world that is far different than the one described in the question, but it did convince me that a secular monastic system dedicated to the preservation and furtherance of knowledge could be possible, and certainly within the realm of belief for a work of fiction. – Dent7777 Dec 27 '17 at 15:05

A Middle-Age level society without animal is simply impossible: animals (cows, horses, mules, etc.) where the only available power sources in those times which could be used for easing the work of men. Same goes for food: no animals means basically no or flimsy proteins income in their diet.

Moreover, if there are no creatures on the dry land, it can very well be that this is because the dry land itself is not life-friendly, i.e. not enough oxygen in the atmosphere to build an ozone layer to shield UV light. So, not exactly the best place to thrive.

• you can get protein from algae and fish, it does not have to be red meat, but you are right about powering the technology – Olga Sep 8 '17 at 7:06
• My thoughts were water wheels and rafts/ships. Would restrict to being coastal/near rivers, at the very least. – Andon Sep 8 '17 at 16:10
• @Andon it may not be pleasant, but look at human history. Historically we've used other humans (slaves) in the role of working livestock. – ench Sep 8 '17 at 21:18
• Hydro power was huge during the medieval period. The first recognizable corporations were formed to develop dams and facilities for harnessing the power of rivers and dams on France. A water wheel could drive a floor mill, smithy, or any other faculty requiring mechanical power. – pojo-guy Sep 9 '17 at 2:45
• Also, the techniques for b burning coal were developed in the medieval time frame, not that it makes a difference since it is to early in the planets life cycle for coal to have formed. Hmmm..... no chance of medieval tech - no fuels available. Darn.. – pojo-guy Sep 9 '17 at 2:48

Since the starting conditions for colonists vastly improved, I am going to write another answer. Basic assumptions:

• colonists can grow crops in local soil;
• local flora and fauna are not toxic to colonists;
• the climate of the planet is similar to Earth;
• colonists, except spacecraft crew, are not trained for space travel and exploration;
• colonists are random people from a developed world (the latter is important);
• colonists brought vast knowledge databases with them, including technical blueprints;
• there is no magic genetic replication/synthesis machine;
• the landing was successful, the majority of craft is intact, but cannot go back to space;
• the land life developed insects and worms (they are necessary for plant pollination and modern soil development);
• there are no birds, reptiles, or mammals;
• seas are full of life, including early fishes

## Skip the Middle Ages

Your colonists cannot and should not go back to the Middle Ages technology since it relies heavily on animals and wood. You have neither.

With 40-75 thousand people (although a more specific number would be better) and functioning landing craft you can go straight to electricity-powered technologies.

You can use your landing ships as shelter and power generator for the first couple of months. Your craft cannot be power-dead since you mention limited manufacturing capabilities and map/resources surveys.

Using one of the vessels build a hydroelectric power plant. A nearby fast-flow river or better a waterfall would be ideal. You are not up to building dams unless your limited supplies include some construction equipment and materials.

## Immediate Population Census and Re-education Centres

It sounds like your colonists are refugees. While some of them were, probably, selected for this mission, some just managed to hop in. Conduct a population survey (better while still in transit to the planet):

• standard demographics (age, sex, marital status, etc.);
• education and practical experience (basically, education and work history plus hobbies);
• medical history (even though your population is big enough to avoid inbreeding and other unpleasant consequences of the population bottleneck, you have to be prepared to deal with a heart attack of your senior mechanic).

Establish a system of triage to divide people according to immediate survival needs:

1. useful skills (engineering, city planning, medicine, electricity, biology, geology, agriculture, etc.);
2. semi-useful skills (psychology, sociology, law, computer programming, etc.);
3. useless skills (finance managing, banking, hospitality services, etc.).

Developed countries have service economies, so the majority of your colonists will have skills not so useful for survival or rebuilding the civilisation. Do not dismiss those skills, though. A hospitality services specialist might not know about catching fish, but they will have insights for setting up comfortable accommodations at a later time.

Setup education and apprenticeship programmes. Some can be started back on a ship, some will have to wait till landing. Teach as many people as possible to produce food. Train electricians and electrical engineers. Start training children and teenagers as research aids for scientists (science involves a lot of data sorting, keeping, and entering; your scientists would appreciate all help they can get with this).

## Food Production

Ration your food from the very beginning. Lock it if needed. After landing start food production immediately. Amadeus has some great suggestions for fishing. Starting agriculture might be challenging, but it is absolutely necessary if you want to rebuild your civilisation.

You can go with conventional farming using crop rotation techniques, but it is a backbreaking work even with animals. You will also depend on weather a lot.

Since you have a lot of knowledge and at least some technology available, you might be better off repurposing some of your equipment for vertical and greenhouse farming and algae breeding. Hydroponics and aeroponics might be within your grasp depending on your original spaceship. If it was used there, you might scavenge the system before landing. If you cannot afford those, go with soil but in a greenhouse use materials from your ship. This will give you better yields.

No matter what kind of farming you decide to do, make sure to start using electricity as soon as possible: lights, machines, heating, etc. If you use the medieval farming approach you might end with almost 90% of population farming. And you need those people to rebuild the civilisation.

## Energy

Electricity and algae fuels are your best options. Start figuring out how to produce them ASAP. Electricity might be easier since any biofuel requires an industry to refine it.

When deciding how to recycle your ships give priority to building an electric grid. It will help to rebuild the industry.

## Mining

Mining, smithing, and such should be your #3 on a list of priorities. You have to replace tools and manufacture new ones. Moreover, since your world does not have wood or bone and you cannot produce plastics, metals will be your main material for years to come.

You will not be able to power your furnaces with wood. You might not have coal. But you can and should use electricity. Start small, grow bigger only when you need to increase production or have electricity surplus.

## Glass

Another important industry that has to be established ASAP is glass manufacturing. Glass is great for your greenhouses. It is also important for keeping science going.

## Pottery and Clay

Without wood and plastics, clay will be your best friend. You can make bricks to build buildings (but I believe concrete is a much better option). But most importantly, you can make pottery to store your food.

## Concrete

Busy your colonists with the invention of concrete. It is a very versatile building material. You can construct roads, dwellings, supports, etc. Concrete manufacturing will be the most important step in building modern infrastructure.

You might consider working on some glazes and paints. Plain concrete is boring and concrete cities are bad for mental health. Splashes of colour and variety of forms in city architecture help to decrease depression and suicide rates. They also provide better stimulation for little ones.

## Timber

Did you bring tree seeds? If you did, it might be a good idea to start growing a forest. It will not be useful for your colonists, but their descendants centuries later might appreciate your effort.

You might not be able to find anything that can be used as timber in your world. Reeds and bamboo-like species still can be used for building. Maybe your world has them. You can start selection work on bamboos so they have more wood-like properties. If you have access to DNA sequencing equipment selection will go much faster.

## Social Aspects

Your population is quite big. You cannot expect that it will just function. You will have to establish some form of government, law, and education systems right from the beginning.

If the majority are civilians a military or totalitarian/authoritarian approach might not work. Although, it would be the most effective for getting things done. Perhaps, you can do with representative democracy, but keep the bureaucracy to a minimum. You need all hands you can get to do the manual work, at least in the first decade.

You will also need laws. There will be crime. You have to decide how to deal with it. Harsh punishments reduce petty crimes but increase violent crime (especially murders). Can you afford jails? Are you going to adopt forced labour? What is your stance on capital punishment?

An educational system is very important for rebuilding a civilisation. You can try to recreate our system or go with other approaches. I think that compulsory early education in combination with apprenticeships could be a good approach in your setting. However, make sure that you do not have guilds. Children should be free to choose their occupations and information must be free.

Your population should be encouraged to grow. Yet, at the same time, you have to have 100% employment. Set up daycare centres, involve elders, encourage parents to bring children to work. If you are keeping a traditional family structure, make sure that fathers are active participants in child-rearing. You might also consider 'communalizing' house chores. That's where your hospitality service specialists come in handy. Set up communal kitchens, cleaning and laundry chores rotation, etc. Make community services mandatory for all men and women regardless of their professions, age, and social standing. Involve children from an early age.

You will have insurgents. There will be people who decide that they can do better on their own. Let small groups go, but do not allow your population to split into 2-3 big camps. You need all those people to work together. It might actually be an interesting plot development if a significant chunk of the population (about 10 000 people) decides to resettle elsewhere and truly start a medieval society. Then you can have two different civilisations on the same planet. You can even purge the records of the Big Insurgency, so once they meet they are very surprised.

## Economy

You will have to start with socialism and communal property. There is no other way because you will be working on huge projects from the start. You cannot allow economic interests and private property to interfere with industrialisation.

Your colony might evolve into something else later. But you should keep it socialistic as long as possible, at least till you achieve about 20th century self-sustainable level of industry and population of millions. Your human resources are very limited. Every individual should have the best chance at realising their potential. They should have free access to knowledge, medicine, and daily necessities. Once you are out of rations you might consider universal basic income.

## Arts, Crafts and Culture

Your colony will develop a unique culture. Most likely it will be a mix of cultures of original colonists adapted to current conditions. In order to specify features of this new culture you need to answer several questions:

• Does the majority of your colonists belong to the same culture? (People from the same culture have easier time working together, but are more constrained when it comes to finding original solutions to existing problems)
• If it was one culture, which one was it? (US culture is very different from Chinese; Chinese colonists will be more likely to setup a system that benefits community first, while Americans might demand more privacy and personal freedoms)
• Are there any minorities of any kind and how are they treated?
• Is there some vision of an 'ideal' society?
• Is there any specific social engineering?

All of these will greatly affect attitudes, expectations, and cultural practices of your people. After a century on this planet, the society will be different and many cultural references will become obsolete. In a world with no forests 'Don't see wood behind the trees' makes no sense. You need to come up with new references and sayings.

Arts and crafts will not disappear completely, but likely to experience a decline. Woodworking, woodcarving, and such will disappear completely. Painting, pottery, stone sculpture, metalwork will flourish.

The architecture will start as very utilitarian. However, as the colony becomes more and more self-sufficient and even wealthy buildings can become more elaborate and richly decorated.

Due to the lack of resources, people might switch back to living on a floor as in Japan. Without wood, it will be hard to make tables and chairs. Rugs and hammocks might replace furniture we are used to now.

You will have to come up with new musical instruments if you want music. Although, your composers can use synthesised Earthen instruments if they retain access to knowledge databases.

Fashions will change considerably due to the lack of traditional materials. In this new world, you will have no wool, leather, silk, or contemporary synthetic fibres. But you might find some interesting replacements (spider silk? fish skin?).

There might be some customs and traditions associated with landing and rebuilding. You can also have some remnants of old world like Christmass.

## Science

Expect a lot of discoveries in fields of marine biology and various bacteria. Your colonists will be in search of replacements for plastics and fuels. They will be researching bacteria a lot since we know that they can do a lot of useful things.

Also, think about all the small things that the first generation of colonists will be missing from Earth. I bet they will come up with some substitutes for alcohol or/and recreational drugs within the first year.

• Insects and worms and other small creatures also add to the available protein. – Andon Sep 9 '17 at 2:57
• algae are easier on an industrial scale, and you need to build industries right from the beginning. 40 000 people need a lot of food. Considering that the majority of them have no idea how to live off the land, do not bother with any food production that is not industrial. If you let them forage for themselves, you can expect up to 95% mortality within the first year. – Olga Sep 9 '17 at 3:58
• Oh, yes. Was thinking further than immediate, though. A hundred years after settling, there might be insect farms and such. – Andon Sep 10 '17 at 4:07

The worse thing is that this early in cycle is that trees wouldn't exist yet meaning no wood. Timber is an easy building material and fuel source.

Land dwelling animals arrived around 400 million years ago but trees didn't develop until another 40 million years later.

Technology can always be rebuilt. The most important things to a settler would be the seed banks.

edit: The OP allows plants, but no trees. Actually this is reasonable; woody trunks may well be an evolutionary response to predation and trampling by early animals; the fact that many trees can survive collision with a car could be a result of withstanding collisions with dinosaurs; or attempts by dinosaurs to eat them.

Medieval technology (and earlier, some from thousands of years ago) is capable of forging steel as good as modern steel, glasses and fine polished lenses, refining metals (like gold, silver, copper, tin) and forming alloys, casting them into shapes.

The OP allows libraries of relevant knowledge, we will rely upon.

For fuel, we can gather plants and leaves and let them dry; starting a fire should be no problem. With 40,000 people, we will have plenty of 1%ers: Not in the wealth department, but the knowledge departments: biology, engineering, human medical, medicine, physics, architecture, astronomy, geologists, mining, metallurgy, refinement, etc. We have to figure out what is edible and what is not.

On Earth we used a lot of animal power for farming. Getting organized we will have to use human power. Eventually we need engines, and what can be built easily using the medieval tech is steam engines. The first steam engine was invented by Thomas Savery in 1698, and in fact a proof of concept of using steam to create rotary motion (as the article shows) was built 1600 years earlier, in Greece.

So everything needed by a steam engine is theoretically available to us, in time. We can mine, and the basics of how to build a steam engine should be in our library and known amongst our population: Given a population of 40,000 we have a 99.998% chance of somebody knowing anything we need to know (computed as $0.5^{\frac{1}{40,000}}$); an even better chance if we include our library, so we just need to get our knowledge map in order (the types of things that specific people are expert in).

The Steam engine allows for turning any kind of plant life into energy for machines to plow fields, dig mines, break rocks, etc. We have had steam powered cars, and of course trains.

I expect this society to leap pretty quickly from medieval to early industrial, late 1800's on Earth, perhaps even early 1900's: They know what electricity can do!

A great deal of technological advancement comes from ideas, and just as teaching is often a very fast recapitulation of key ideas that advance something, these settlers already have the key ideas, they brought them along. For example, nobody has to come up with the idea of the car, truck or steam locomotive, or convince anybody that a locomotive on rails could transport thousands of tons. They may have to work out some details, but all of them know this is both possible and valuable and will work.

Nobody has to invent the tractor, thresher, or the idea of industrial farming on a vast scale. Nobody has to invent the lumber mill or casting iron. Nobody has to be the first to try using steel beams to build tall buildings. Aircraft do not start as a curiosity that nobody really knows what to do with; nobody doubts plastics (or something similar) and rubber can be made from plants and everybody knows what they are good for, nobody doubts the use or existence of tough light ceramics or metal foams and their utility.

Heck, nobody has to invent algebra, calculus, physics and mechanical engineering, or medicine for that matter, or the hundreds of crucial and game changing ideas that brought us from the middle ages to the modern age. (The idea of germs, extreme sanitation, and doctors simply washing their hands before and after treating patients or doing surgery has saved literally millions of lives, as has the simple idea of boiling water before drinking it or using it on an open wound).

Given 40,000 people drawn at random, anything known on earth by 1 in a 1000 people should be known by a few dozen in this group.

Of course the biggest cultural change is going to be a seafood and vegetable society. They need to feed themselves fast!

I presume the fish are edible; at least edible if cooked. The best fast tech I know of for catching Earthly ocean fish without wood are stone fish traps. Remnants of some of these have been found from over 2000 years ago; it is not a new idea. They do need to be located in chosen places based on current and tides, they do not necessarily just work anywhere.

There is a tidal trap: The idea is to find a place where high tide is several feet, and fish come to feed in waters too shallow to reach during low tide. Build a semi-circular loose stone fence (meaning don't fill in the gaps with mud), of a specific height, tight enough that larger fish cannot swim through it. Place it just before the water line at low tide: You want fish to be able to swim over (or around) your fence at high tide, but be stranded on the shoe by it at low tide. At low tide the water drains out, between the rocks, and you go collect your fish, using a rock to kill them.

There are current traps: On earth at least, fish do not reverse course to get out of a trap, and they don't seem to have any memory of how they got someplace. So the current trap is built as a fence (using rocks again), in the shape of a 'comma'. Fish swim with the current along the shore line; some end up on the shore side of this fence (at the tail of the comma). They won't reverse course to get to the other side. The fence guides them into a circle; the ball of the comma, and the fence spirals inward for a loop, trapping fish in a pool. they can't figure out how to reverse course or swim against the current, so they become concentrated in the ball of the comma, making them easy to net (vine nettings), brain (with rocks), or just get in and throw them out by hand. Plus it keeps them alive and fresh until needed.

Other fish traps are ancient also; see this weir (could be build with rock), and the double-heart (which is built with rock), both of which can be adapted to work offshore in a current, both of which can be built quickly by many hungry settlers working together.

Fishing Wier. Click on the picture to enlarge.

Double Heart of Stacked Stones fish trap. Click on the picture to enlarge.

so we have food and water (steam distilled ocean water, can be made even using clay pots), and quick shelter. The society progresses by steam engine and quickly implementing their knowledge of basic sciences. They will arrive at a full electrical stage within a century, IMO. Of course they don't use traps forever, they will be building steam powered boats and fishing nets pretty quickly.

Other details (crops, what they can use for fiber and rope, whether they have coal or oil products) are all going to be peculiar to what you put on the planet for them to use. Something like cotton would be great for a textile industry, but what they get is up to the planet designer, or perhaps additional world-building questions.

You want those knowing the most about geology and mining in the group to focus on finding simple ores for tools, and progressing toward iron. Flint is not of biological or animal origin; that is the first thing to find; it can be shaped by using flint rocks as hammers, knapping can be self-taught to make razor sharp hand tools very quickly. These can be used for simple tasks like harvesting plants for fuel and food, killing and butchering fish, and digging for ores. The majority of people can be put to work both on these tasks, on building fish traps, and on becoming specialists in making these tools.

Use other specialists among the 40,000 to make teams of surveyor/explorers; to find the best candidate places to settle: For fish production, farming potential, and mining potential. If possible for caves that can serve as initial shelter and shade from the weather.

Use plant specialists to understand and start categorizing the new flora (categorization being the first step in science), with an eye on finding fibrous stalks, leaves, or roots to be able to make strong ropes and nets (for fish and woven mats that have utility in shelter and comfort).

• I wonder if random 250 people are capable of building even a primitive steam engine from zero. I know a lot of people who know the theories behind it, but I know just 1 person who knows something about blacksmithing. And I am not sure he himself knows how to mine and refine metal he uses in the smithy. Can you expand on this point? – Olga Sep 8 '17 at 13:08
• @Olga Suppose 2% of people know something technical about steam engines; so a 98% chance a given person does NOT. but $0.98^{250}$=0.0064 chance nobody knows it; or a 99.36% chance somebody knows it. The same goes for most other knowledge; if people are chosen at random there is a strong chance of getting at least a college educated engineer, math guy, biologist, naturalist, etc. Further, just knowing the basic principles of steam engines, if your life and the lives of your children depend on it: You will experiment until you figure it out. No "oh well, guess we'll die." – Amadeus Sep 8 '17 at 13:22
• It is not about knowing how to build it. For the purposes of my question, they can have blueprints ready. It is about actually building something from the ground. It is a new world with no infrastructure, no mines, no ore refineries, no smithies. Before you can start building even a basic mechanism you have to have the parts built. And in order to build parts, you need to process raw materials. And before you can process raw materials, you need to collect them somehow. Not to mention that you might have to transport all those materials long distances. – Olga Sep 8 '17 at 13:33
• @Olga make sure they have copies of The Toaster Project, and Build Your Own Metal Working Shop series. – ench Sep 8 '17 at 21:29