What was the first animal on Earth?

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asked May 16, 2023 in Home Work Help by Crybablo (1,440 points)
What was the first animal on Earth?

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answered May 16, 2023 by Wenja6765lo (2,880 points)
The first animal on earth is sponges.

And while the chemical compounds from sponges are preserved in rocks as old as 700 million years, molecular evidence points to sponges developing even earlier.

Some types of sponges can get to as big as 6 feet wide and 6 feet tall.

Although most sponges are less than a centimeter tall or around 3 to 4 feet tall.

Not all sponges are from the sea.

Sponges are from the sea as well as oceans, lakes and even rivers.

Sponges are thought and said to have evolved directly from Protozoa.

Sponges first appeared around 2.5 billion years ago and is thought to be the first animal which evolved from protozoa.

Among extant animals, only sponges could have evolved directly from protozoa without changing feeding mode.

The key problems in understanding animal origins are therefore how and why sponges evolved from a craspedid-like stem choanoflagellate and later generated all other animals.

Sponges are older than dinosaurs as fossils of sponges have been found that are estimated to be 890 million years old.

According to scientists sponges are the oldest animal besides dinosaurs.

Sponges do not have a nervous system or the ability to possess any type of senses.

3 facts about sponges are.

Sea Sponges are animals, not plants.
Sea Sponges have been in the ocean for 500 million years.
Sea Sponges don't move, but they filter lots of water for food (plankton) and oxygen.

The 3 types of sponges are the Hexactinellida (glass sponges), the Demospongia, and the Calcarea (calcareous sponges).

The thing that is unique about sponges is they can live for thousands of years and they are exclusively aquatic, filter feeders that actively pump water through their bodies to eat, breathe and excrete.

Specialized Cells: Sponges have special collar cells (or choanocytes) that are unique in the animal kingdom.

What best describes a sponge is the ocean or sea sponge is multicellular, heterotrophic, lack cell walls and produce sperm cells.

Unlike other animals, they lack true tissues and organs.

Some of the sponges are radially symmetrical, but most are asymmetrical.

Sponges do not have a heart, brain, eyes, mouth, nose or nervous system or blood.

Sponges are not edible as they are too tough to chew and eat.

Sponges are really not vegan because sponges while they look and act like plants they are actually classified as animals and sponges are a part of the animal Kingdom.

Also because they are tough the sea sponges and ocean sponges are not edible so they should not be eaten and they would have a bad taste as well.

Sponges live at the bottom of the ocean.

Sponges inhabit depths from the intertidal zone of shallow, shelf seas to the lower continental slope / abyssal plain transition (depth approx. 3000m) of the deep sea.

Sponges do not have any organs, heart, brain, blood, eyes or a mouth.

The most common type of sponge in the ocean is the Desmospongia sponge.

The 4 types of sponges in the ocean are Homoscleromorpha, Calcispongiae, Hexactinellida, and Demospongiae.

Sponges in the ocean reproduce asexually through sperm and eggs.with your sponge.

Most poriferans that reproduce by sexual means are hermaphroditic and produce eggs and sperm at different times.

Sperm are frequently "broadcast" into the water column.

As for what an ocean sponge is made up of.

The skeleton of a sponge is formed from spicules which are made of silica (a glass-like material) or calcareous (calcium or calcium carbonate) materials, and spongin, a protein that supports the spicules.

Sponge species may be most readily identified by examining their spicules under a microscope.

The function of a sponge is to provide shelter for some aquatic life and also to draw water carrying food particles into the spongocoel using the beating of flagella on the choanocytes.

The food particles are caught by the collar of the choanocyte and are brought into the cell by phagocytosis.

Digestion of the food particle takes place inside the cell.

Sponges rely on movement of water through their bodies to carry out body functions.

Oxygen dissolved in the water diffuses into the surrounding cells.

Carbon dioxide and other wastes, such as ammonia, diffuse into the water and are carried away.

Sponges are important to humans and the ecosystem.

Many natural products from sponges have shown a wide range of pharmacological activities such as anticancer, antifungal, antiviral, anthelmintic, antiprotozoal, anti-inflammatory, immunosuppressive, neurosuppressive, and antifouling activities.

Sponges are also very critical components of the ecosystems of coral reefs, where they provide shelter for a variety of organisms including shrimp, crabs, and algae.

They are also a source of food for many sponge-eating fish species.

The oldest sponge is believed to be around since 535 to 600 million years ago.

In a 2014 review of the evidence for early sponges, Antcliffe and his colleagues found that the oldest convincing animal fossils are sponge spicules found in Iran dating to roughly 535 million years ago—and he says no recent studies have yet changed his mind.

A sponge has a lifespan of around 500 to thousands of years.

Some sponges can live for over 2,400 years and sometimes longer.

Sponges grow and can be found in the ocean.

Sponges are simple invertebrate animals that live in aquatic habitats.

Although the majority of sponges are marine, some species live in freshwater lakes and streams.

They are found in shallow ocean environments to depths as great as five kilometers (km).

Sponges do lay eggs and reproduce asexually.

The sponge produces sperm and eggs and also reproduce asexually.

Some species of sponge are monoecious, others are dioecious.

Sponges eat and obtain their food by passing water through their bodies in a process known as filter-feeding.

Water is drawn into the sponge through tiny holes called incurrent pores.

Sponges do not have any blood or any organs and live by absorbing all of their gasses and nutrients from the water and returning wastes to the water by direct diffusion through cell walls.

Sponges do poop but not in the same way humans do.

Sponges actually excrete a form of “sponge poop” which is carbon that other organisms feed on.

Sponges do not have any eyes and they cannot see.

Sponges have no nervous system or organs like most animals do which means they don't have eyes, ears or the ability to physically feel anything.

Sponges also do not have any brains.

Sponges are among the most primitive of all animals.

They are immobile, and live by filtering detritus from the water.

They have no brains or, for that matter, any neurons, organs or even tissues.

A sponge is not a fish although a sponge is considered a type of animal.

A sponge is actually an animal although a sponge in the ocean thrives and looks like a plant.

A sponge is a living thing.

Sponges are "sessile" animals (they don't move around) and they live by pumping large volumes of water through their bodies and filtering out tiny organisms and organic particles as food.

Sponges are animals and not plants because a sponge is, in essence, a multicellular organism with no organs or tissues, but with specialized cells, which distinguishes it from small multicellular protists.

Sponges are considered to be one of the simplest animals, primarily because their bodies are not organized in organ systems or even tissues.

Rather, sponges are made up of a grouping of cells that work together to contribute to meeting the daily needs of the sponge.

Sponges are simple creatures, yet they are expert filter feeders, straining tens of thousands of liters of water through their bodies every day to collect their food.

Their mastery of this complex behavior is all the more remarkable because they have no brain, nor even a single neuron to their name.

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