The effect of the environment on living organisms

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Natural environments are subject to weather, location, height, if water is nearby and what kind of water this is the neighboring environment, and so much more. These factors affect what plant species can grow in an area. And these, in their turn, affect what animals can live in that specific area. Taking all the other factors into account. Evolution is a way to make sure that species can keep surviving. It's a process of elimination. If you can't keep up with changes, or your new evolutionary trait is useless, it, or you, will likely die out.

Hi! My name is Tessa, I’m a Dutch artist, art director, and creative project manager. I love to share my passion for this craft, nature, art and fantasy, and do that by creating this archive and community, alongside my company Tez Art & Design.

Table of Contents (Click to (un)fold)

This article is an extension of ‘The importance of environments in creature design‘. But if you’re just curious about what effect environment has on living organisms on our planet: You’re still in the right place!

Specializations of living organisms

Every. and I mean EVERY living organism specialized. It’s impossible to have them all written down, but I like to bring some awareness as to what kind of specializations you can expect among living organisms. This will help you get a better understanding of what’s possible, and how the environment affects organisms. Which will then help you out on your creature designs.

Food availability

Food availability is probably the most obvious factor of all, If there’s something we learn in school: It’s that there’s something called ‘the circle of life’. Predators eat prey which more often than not are herbivores. These herbivores in turn eat grass, leaves, plants, herbs, you name it and fertilize it with their feces. Feces of herbivores and omnivores are more nutrient rich than that of predators. When animals die, they return energy back to the soil surrounding their dead bodies.
Take away one chain and the whole balance is off, with devastating results:

Removing the predator

The presence or absence of predators is a huge factor in how the environment will develop over time.
Photo by Thomas Bonometti on Unsplash

We saw this happen in Yellowstone where they recently re-introduced wolves to stop herbivores from damaging the landscape even more. Wolves were hunted to extinction in Yellowstone national park because they started to hunt farm animals after people took their hunting grounds and the feeding grounds of their main prey: Elk. Between the 1800s and the 1900s ‘predator control’ was a common practice. But when wolves died out in the area, elk took over. Not having a natural predator, apart from the occasional bear, the only major cause of death was extreme snowfall.
With global warming came less snowfall and elk became a problem.

Imagine a 1,5-meter tall elk, more than a quarter of a million of them in an area that’s fit for only 6000 to 8000. Snowfall wasn’t so much the cause of death, it was only a factor that tipped the balance. Having a quarter of a million animals in a way too small area, all eating the same vegetation, resulting in a lack of food. So when these animals needed their reserves for wintertime, they didn’t have any, causing extended suffering and slow deaths.

But this also caused a cascade of events among other animals. As everything edible was eaten, there was little vegetation left for other animals. Beavers for example thrive only in areas filled with trees, but there were almost none left. As beavers couldn’t do their work. some areas that would have been flooded otherwise and be perfect spawning grounds for animals that can’t thrive in running water, weren’t there anymore. Plant diversity dwindled for the same reasons,

These die-offs caused such damage that in 1995 the state decided to re-introduce wolves. This was and is a great success to this day. Natural balance has been restored among all animal- and plant species.

Remove herbivores

These relatively friendly Highlanders are used in nature reserves to keep vegetation low and the landscape open.
Photo by Patrick Schneider on Unsplash

Removing herbivores from an area is a great way to have plants grow in abundance. But this takes away the food source for carnivores. They will leave the area as well, or simply die because they have nowhere to go. Another scenario is that they start predating on other animal species, causing them to die out. In some cases, this may be beneficial, for example when there are too many rabbits in an area. But as long as the habitat is large enough, you don’t want to meddle with nature. It will balance itself out.
A third scenario is devastating for predators that don’t use ambush tactics but instead rely on group efforts or endurance, like wolves: Is overgrowth. They do way better in open areas. When there are no large herbivores available: Plants will take over, making it even harder for specialized animals like the wolf to survive.

Removing vegetation

This is the most devastating scenario. Remove vegetation and herbivores will grow hungry and weaken. They will survive for a while on what’s left here and there, or on bark for example. Predators however will do great. There will likely be a baby boom because the predatory animals are so weakened. There is plenty of food available whenever they feel like munching down on something. But by the time the (next) winter hits, herbivores will be weakened to such an extent that (nearly all of them) will die. Leaving the carnivores without food. By springtime, if they manage to survive the winter, there will be new offspring that need to be fed, while there is no food anymore to hunt for. Resulting in a collapse of predatory animals.

Nature of course will restore itself if we let it, plants will start growing again, animals will inhabit the area, but especially larger animals more often than not won’t return after such a big ecological collapse. This has partially to do with how fragmented nature is these days because of human habitation, but this balance is also so remarkably fragile. All of the factors need to be present to have a good balance, and this usually doesn’t happen. The habitat will change a lot because of this, and become inhabitable for the species that used to live there before the ecological collapse. This is the most significant way to cause extinction without directly killing the animal.

Water availability

Dromedary, like camels, are specialized living in the desert.
Photo by Wolfgang Hasselmann on Unsplash

Water availability is of course a major factor. Plants need water, and so do animals. All species specialize toward water availability, just like they do with food. This is why cacti or the Baobab tree can store so much water, while other plants die after a day in the scorching sun without water. Did you know that house cat needs so little water because they used to be desert animals? The majority of their water intake comes from their prey. The only drink relatively much as our pet because we tend to feed them dry food, which is very unnatural for them. But way more animals specialize this way. We know of the camel or the dromedary who store fat and water in their humps for later use. But did you also know that the kidneys of Dorcas Gazelle are so efficient that they pee solid pellets or uric acid?

Remarkable isn’t it? But imagine you’re a creature that only has access to salt water. We would die for sure in no-time. But there are many birds and reptiles out there that found ways to live off of salt water. They have glands that get rid of excess salt. And many saltwater fish have specialized gills with the same function.

There are way more specializations like this, but it gives you a good sense for some solid inspiration! There is way more out there in the world than you or I know. Even scientists don’t know everything. So always push the boundaries of your creature designs!

Insular dwarfism an gigantism, evolution on steroids

We discussed some specializations, and as said before, it’s impossible to discuss them all. But for your creature designs: Knowledge is key. Have you ever heard of insular dwarfism or gigantism? This happens when animals get stuck on a little patch of nature. This usually are island, remote caves, desert oasis, and other small isolated habitats. On places like this evolution speeds up, animals specialize and adapt after a few generations, something that would take thousands of years elsewhere, if at all.

Why does insular dwarfism or gigantism happen?

I’d like to dig into this really deep, but I won’t for your sake. I’d like to keep it short for you. after all you likely want to pick up some fun facts or inspiration for your creature designs, and not receive a full lecture.
So, how does insular dwarfism and gigantism happen? As you know: Animals adapt to their environments more quickly than the environment does to the animals. Little food can be better survived if you’re a small animal. Abundance of food can cause the opposite to happen. And if you need to travel great distances to get from food source to food source, being large can be really beneficial as well.

We see insular dwarfism and gigantism happen on small isolated islands, to islands like Curacao. So an island can be pretty big to still cause this effect. And it’s all about food supply and survival of the fittest. But also, who got there first.
Dwarfism is usually the result of lack of food, where gigantism is usually the result of an abundance of food.

Especially mammal predators have trouble reaching these remote areas. So the natural predator of a species can be completely absent. Allowing predatory animals which can cover great distances, like birds or reptiles, to become apex predators. Because of this, they have an abundance of food and can grow larger after a few generation.
Reduced predation also causes prey animals to grow larger.

Effective predators like wolves tend to become smaller because there usually is not enough food for large packs of animals. In isolated areas it really beneficial to be small when you’re a really effective predator. But the same counts for herbivores. If you’re small you need less food and you need to travel less to get what you need.

Some other examples

There are many factors responsible for dwarfism and gigantism. Here are some other factors:

  • Founder effect is another factor. Larger animals within a species have more chance of colonizing new land. Especially when they’re territorial. Survival of the fittest is the key here.
  • Smaller size usually means shorter gestation periods allowing for more offspring, especially in a time of abundance.
  • Deep sea gigantism goes hand in hand with low temperatures. It causes an increased cell size and lifespan. The increased size helps the animal to cover great distances in search of food and a mate. The deep sea is so expansive and so few animals and plants live there, that size really makes a difference for many species.
  • Deep sea gigantism is thought to combat asphyxiation. Increased dissolved oxygen increases with water depth and pressure. Large organisms can take in more dissolved oxygen.

Terrestrial insular gigantism species

There are way more species that display gigantism, but here are some examples.

Kakapo are really friendly and funny looking parrots.
Image by Department of Conservation, Wiki
  • Tenerife giant rat
  • St. Kilda Fieldmouse
  • Fossa (Mongoose)
  • Philippine Eagle
  • Kakapo (Parrot)
  • Tasmanian Supurb Fairywren (bird)
  • Angel Island Chuckwalla (Iguadon)
  • New Caledonian Giant Gecko
  • Kishinoue’s Giant Skink
  • São Tomé Giant tree frog
  • São Tomé Giant grass frog
  • Coconut crab
  • Kauri land snail

Marine insular gigantism species

Giant Isopod. Don’t want to have this crawl in your garden, do you?
Image by NOAA , wiki
  • Big Red jellyfish
  • Giant isopod
  • Giant ostracod
  • Deepwater stingray
  • Giant sea spider (crab)
  • Giant amphipod
  • Japanese spider crab
  • Giant oarfish
  • Seven-armed octopus
  • Colossal squid
  • Giant squid
  • Bigfin squid

Terrestrial insular dwarfism (and marine animal note)

I had some trouble identifying insular dwarfism in marine animals, if you have some good examples of that, please let me know!

Island fox are really small.
Image by Pacific Southwest Region USFWS from Sacramento
  • Cozumel thrasher (bird)
  • Nosy Hara chameleon
  • Pygmy three-toed sloth
  • Zanzibar red colobus (primate)
  • Zanzibar leopard
  • Island fox
  • Tamaraw (Buffalo)
  • Dahlak Kebir gazelle
  • Florida Key deer

Why dinosaurs were so large

Back in the days our planet was really an alien planet compared to what it is today. The temperatures were a lot higher and the carbon dioxide level was four times higher as well. This was ideal for plant growth as plans use carbon dioxide for photosynthesis. High carbon dioxide levels cause plants to grow a lot taller. Ground-dwelling herbivore dinosaurs had to grow taller as well. Because these animals were so large they were hard to take down, but also were a huge food-supply. These factors caused predatory dinosaurs to grow larger as well. And because there was so much food available for the herbivores, it was easy to grow that large too.
All in all, these times were perfect for everything to grow remarkable large.

Fun fact:
Did you know that dinosaur bones are hollow? Because of this, dinosaurs were a lot lighter than you would think. Did you also know that birds, very close relatives to dinosaurs, also have hollow bones?

Modern day dinosaurs

Under side of a horseshoe crab.
Image by Binh Giang

Yep, they exist. Take alligators and crocodiles. sharks and sea turtles. Snakes, many crustaceans, platypuses, lizards, horseshoe crabs and even the chicken at your local farm. They’re all descendants of ancient crocodiles. Some are loosely related, others more closely, or even lived in the days of the dinosaurs, like the horseshoe crab. Wonderful isn’t it?

Other specializations

As said before, there are many more specializations. But let me run you through a few to help your creative juices to flow!

The eye spots on this butterfly are very obvious.
Photo by Krzysztof Niewolny on Unsplash
  • Especially large grazing animals that live in tundras or on the Savannah learnt to migrate (gazelle, zebras, wildebeest, caribou, etc). Their lives revolve around it and their bodies are perfectly suited to these migrations. They give birth before the migration, long before food runs out. And when it does, they go in large groups, because this is a lot safer considering the young animals and predatory animals. By that time the young are strong enough to take on this migration.
  • Some insect like bees huddle together and vibrate their wings to stay warm during cold periods. This is also why they store honey. To survive the cold, when there are no flowers to feed them consistently.
  • Many animals learnt to adapt to life in cities. Think of mice and rats, but also raccoons and foxes. Many birds start to sing earlier and/or sing louder to make sure they’re heard in cities with a lot of noise pollution.
  • Animal species that hunt venomous creatures like snakes tend to be immune to poison, or specific kinds of poison. You can find them right in your backyard. Think of hedgehogs, badgers, opossums, but also the king snake which isn’t venomous itself.
  • Mimicry is a way to fool a predator into thinking their prey animal is something else, something poisonous, or is looking at them. These animals do this by mimicking eyes on their wings, like praying mantis, or butterflies. Or by mimicking a poisonous animal species while they are not poisonous themselves.
  • Camels have big humps on their backs to store fat and water. But did you also know they have very long eyelashes to prevent sand from blow in their eyes? A 3rd eyelid with the same goal and block out sunlight, that they have thick fur on the sun-facing parts, and little hair on the parts facing down to get rid of excess warmth?
  • Wood frogs can freeze their blood during cold season. They stop their heart and awaken when spring arrives.
  • Black areas around the eye of an animal stop glare from the sun.
  • Arctic fish have ‘anti-freeze’ in their bodies. This is a protein that binds to ice crystals in their blood. Stopping it from creating more.
  • African bullfrogs make mucus homes to survive dry season.This membrane hardens into a cocoon. The frog can live in there for up to 7 years waiting for rain to come.
  • Whales, elephants, hippo’s, rhino’s, giraffes, okapi, peacocks, and alligators use infrasonic sound to communicate over great distances. You can see this vibration best when a surfaced crocodile uses this sound.

More interesting reads on creature design


Well, as you can see, there are so many specializations on this world alone. And we barely scratched the surface! Always keep your eyes open and take your time to learn more from documentations, or read, like you’re doing now. Always keep asking questions and always stay curious! You will get there.

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