Why did animal life originate in the oceans rather than on the land?

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Why did animal life originate in the oceans rather than on the land?

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Anonymous 0 Comments

There’s a lot of good points in these comments, but there’s one I haven’t seen, so I’ll add that as well:

Liquid is the most effective at letting atoms and molecules meet.
The first step of life being created is self-replication. In the beginning everything was just atoms going around, then molecules going around. But for more complex molecules to be created the odds of those atoms an molecules just colliding by accident is really small. In solids the atoms plainly doesn’t move about enough to collide with other atoms. In gasses there is so much room in between the atoms that they will go long distances before bouncing into another atom. Liquids on the other hand is the perfect combination of atoms and molecules moving around but still being close to each other

Anonymous 0 Comments

Basically we had to evolve the ability to carry around a private little ocean with us. The water content of our Blood, cell contents, and other fluids make up a majority of our weight because we need water as a solution for all of our chemical processes to happen in.

Anonymous 0 Comments

Life is basically chemistry. Chemistry is a lot easier when everything is floating around in a solvent.

Anonymous 0 Comments

best/simplest answer is because of how useful water is. it was just the best place for life to start.

it allows exchange of particles or elements like oxygen much easier than on land, is fairly stable, and protected things from radiation when the earth couldnt do it alone.

small not quite life started there. small things grew from chains of chemicals that then mixed and got more complicated, eventually being able to move and reproduce in better and more efficient ways. land didnt provide such a perfect situation as quickly or easily – plants were the only thing on land for eons.

plants and algae were doing their own thing. bacteria started forming and getting more advanced. viruses and similar were doing the same, they got bigger and/or stronger.

an egg is just a giant cell that cant move on its own, so it relies on its parents for safety. cells getting more complicated created animals that could lay eggs; those eggs were in the water, and animals got so diverse and different that some stayed in the water, and some headed to land to find new food and space. legs and gills were a major upgrade there, including adapting to being dry with thick skin/scales.

eggs needed the water still, but being closer to land meant that they could eventually leave, return, lay their eggs, and go back onto land again. an egg allows a creature to use less resources to reproduce and allows them to leave them behind when needed.

over time the shells hardened and could hold water, and allow air to pass through; these are the eggs we know today. this change alone let animals spread further and develop faster from the new resources and space available. the new arms race starts again but on land.

water allowed things to mix and grow in a much faster rate than land could ever do. the arms race in the ocean is a whole story in itself and would make this comment 10x longer.

i hope this is a good answer lol

Anonymous 0 Comments

Many chemical reactions require water. The very beginnings of life, essentially the first cells are basic chemical reactions that must happen in water.

Among the many reasons other posters have stated, I think simply water being the medium is the most important to the origin of life.

[In chemical reactions, water can act in many ways. Some of these include as a hydrogen bond donor or acceptor, as well as a proton (H+) donor or acceptor, which allows water to facilitate reactions in many ways.

Most importantly, water acts as a solvent in many chemical reactions. In many chemical contexts, the chemical reaction does not take place without water. Here, water allows these reactions to proceed.](https://www.studysmarter.co.uk/explanations/chemistry/physical-chemistry/water-in-chemical-reactions/)

Anonymous 0 Comments

Water is a far better medium for life to start, molecules move more freely making it easier for them to combine into something alive an once you have life it has a better chance of water since it gives better protection from temperature changes and radiation from the sun

Anonymous 0 Comments

Water is easier. It took a while for creatures to evolve the ability to survive outside of water, those are more complex systems. And basically the answer we evolved was to take the ocean with us, inside.

People often think that evolution and biology is directed… “How does that O2 molecule know when to bind with the platelet?” It doesn’t. It’s pretty much random, they have to bump into each other, we’re just dealing with trillions of molecules at a time so the chance balances out. It’s the same between water creatures and land-based. Those lungs were a lot more complex than gills, so it took creatures longer to randomly mutate and get it right and viable. Thus, water critters happened first.

Anonymous 0 Comments

Temperatures in water don’t change very quickly whereas temperatures in the air can change much faster. Stability was precious for creatures to thrive in environments with limited oxygen. Only a few species could weather the hellish environment on the surface.

Anonymous 0 Comments

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Anonymous 0 Comments

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