Evolutionary discovery to rewrite textbooks

Evolutionary discovery to rewrite textbooks
Choanocyte cross section. Credit: The University of Queensland

Scientists at The University of Queensland have upended biologists' century-old understanding of the evolutionary history of animals.

Using to investigate how multi-celled animals developed, their findings revealed a surprising truth.

Professor Bernie Degnan said the results contradicted years of tradition.

"We've found that the first multicellular animals probably weren't like the modern-day sponge , but were more like a collection of convertible cells," Professor Degnan said.

"The great-great-great-grandmother of all cells in the , so to speak, was probably quite similar to a stem cell.

"This is somewhat intuitive as, compared to plants and fungi, animals have many more cell types, used in very different ways—from neurons to muscles—and cell-flexibility has been critical to from the start."

The findings disprove a long-standing idea: that multi-celled animals evolved from a single-celled ancestor resembling a modern sponge cell known as a choanocyte.

"Scattered throughout the history of evolution are major transitions, including the leap from a world of microscopic single-cells to a world of multi-celled animals," Professor Degnan said.

Evolutionary discovery to rewrite textbooks
The adult sponge Amphimedon queenslandica. Credit: The University of Queensland

"With multicellularity came incredible complexity, creating the animal, plant, fungi and algae kingdoms we see today.

"These large organisms differ from the other more-than-99-per-cent of biodiversity that can only be seen under a microscope."

The team mapped individual cells, sequencing all of the genes expressed, allowing the researchers to compare similar types of cells over time.

Fellow senior author Associate Professor Sandie Degnan said this meant they could tease out the evolutionary history of individual , by searching for the 'signatures' of each type.

"Biologists for decades believed the existing theory was a no-brainer, as sponge choanocytes look so much like single-celled choanoflagellates—the organism considered to be the closest living relatives of the animals," she said.

"But their transcriptome signatures simply don't match, meaning that these aren't the core building blocks of animal life that we originally thought they were.

Evolutionary discovery to rewrite textbooks
Cells and flagella are labelled red and nuclei blue. Credit: The University of Queensland

"This technology has been used only for the last few years, but it's helped us finally address an age-old question, discovering something completely contrary to what anyone had ever proposed."

"We're taking a core theory of evolutionary biology and turning it on its head," she said.

"Now we have an opportunity to re-imagine the steps that gave rise to the first , the underlying rules that turned single cells into multicellular animal life."

Professor Degnan said he hoped the revelation would help us understand our own condition and our understanding of our own and cancer.

The study has been published in Nature.


Explore further

A short jump from single-celled ancestors to animals

More information: Pluripotency and the origin of animal multicellularity, Nature (2019). DOI: 10.1038/s41586-019-1290-4 , https://www.nature.com/articles/s41586-019-1290-4
Journal information: Nature

Citation: Evolutionary discovery to rewrite textbooks (2019, June 12) retrieved 23 August 2019 from https://phys.org/news/2019-06-evolutionary-discovery-rewrite-textbooks.html
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Jun 12, 2019
The very first cells that were created in the shallow waters of Earth were Single celled that were very primitive with only the basic structure of feeding, digesting and eliminating. Then later, 2 or more single cells united to become a multi-celled animal that had much more than basic structures, as it also had a heart and blood vessels. As time went by, the cellular structure of each animal continued to divide and grow, and the animal became large with a need for more food. The structures of the animal diversified and became plants or animals, depending on its environments.

Jun 13, 2019
How can multi-cell organisms magically appear? But even more importantly, how can a cell magically appear from nothing? A single cell is SO complex that it is impossible to have been formed from random processes. Anyone claiming so must needs have his head examined. And the blind sheep following the blind evolution teachers should wake up to reality.

Jun 19, 2019
How can multi-cell organisms magically appear? But even more importantly, how can a cell magically appear from nothing? A single cell is SO complex that it is impossible to have been formed from random processes. Anyone claiming so must needs have his head examined. And the blind sheep following the blind evolution teachers should wake up to reality.


There was nothing random about the creation of the first single-celled organisms. They were created in the shallow waters by the Creator God who programmed the life forms for the basic signatures of life. At the time, there were no plants or animals until the single-celled creatures began to coalesce into multiple cells where the single cell divided and mutated into multiple cellular life forms that were more complex than their predecessors. Both of these types of cells did NOT come from nothing. They were made/created from the resources that were in the waters already. Terran resources. Atoms > Elements > Molecules

Jun 19, 2019
I choose to use the term "mutated" rather than evolved, because with evolution, there needs to be an ancestor to have evolved FROM. Some babies are born with 2 heads and 1 body, with 2 different personalities. They are not evolved but had mutated in the womb where one twin's body was absorbed by the other twin, except for the head and brain. They are "conjoined" twins.

Jun 19, 2019
Jebus didn't make animals. And you're not a mind-reading alien.

Get over it.

Jun 19, 2019
--contd
However, the first multi-cells that were washed up on the shores of the early Earth were of the Plant species. Some of those plant species remained in the waters, but those who were thrown up on the shores of islands were able to attach roots to the soil and grew, while the ones who were water-bound became food for the fish and sea animals. Then the sea animals evolved legs and feet, arms and hands as they crept up onto the land. Some went back to the sea, but most stayed on land and ate the plants and preyed on other animals.
So there were Plants, land animals and animals and fish of the seas.

Jun 19, 2019
Jebus didn't make animals. And you're not a mind-reading alien.

Get over it.


Who is this jebus that you seem fond of mentioning now and then?
Exactly HOW do you know that I'm not a mind-reading alien? Where is your evidence?

Jun 19, 2019
Actually on Earth, meanwhile, cyanobacteria altered the atmosphere.

Not only do you not know astrophysics, you also don't know evolutionary biology.

For you people, jebus made everything. Only jebus didn't know any astrophysics or evolutionary biology or for that matter any math.

Jun 19, 2019
Exactly HOW do you know that I'm not a mind-reading alien?
Because you haven't read my mind yet.

I am thinking of a song, and as it happens listening to it.

Name the song.

Get to it.

Oh, and this is bookmarked. Thanks for finally confirming that's your claim.

Jun 19, 2019
Exactly HOW do you know that I'm not a mind-reading alien?
Because you haven't read my mind yet.

I am thinking of a song, and as it happens listening to it.

Name the song.

Get to it.

Oh, and this is bookmarked. Thanks for finally confirming that's your claim.


I am not interested in revealing your thoughts, at least not until your blackened soul is about to be removed from your body.
Now who is this jebus that you keep referring to? Is it animal, vegetable or mineral? I am not aware of any such person.

Jun 21, 2019
"Now we have an opportunity to re-imagine the steps that gave rise to the first animals, the underlying rules that turned single cells into multicellular animal life."

Well said, but there is just one problem with that statement. What makes you think your imagination has anything to do with reality? The first time, it was way off! But it was believed for a long time and then when finally they found a way to test it, they realized their imagination had nothing to do with reality.

Why should the next idea imagined be any different?

This is the problem with historical science. I'm sure we believe many things to be true that really aren't true. If only we could test our beliefs like scientists are supposed to do, we could know, but most of the time, we are left to our imagination. This means we're left w/a lot of untested hypotheses, many of which are probably not true. And we keep on building other hypotheses on these hypotheses. And this is supposed to qualify as science?

Jun 21, 2019
The very first cells that were created in the shallow waters of Earth were Single celled that were very primitive with only the basic structure of feeding, digesting and eliminating. Then later, 2 or more single cells united to become a multi-celled animal that had much more than basic structures, as it also had a heart and blood vessels. As time went by, the cellular structure of each animal continued to divide and grow, and the animal became large with a need for more food. The structures of the animal diversified and became plants or animals, depending on its environments.


Nice imagination! Now if only you could do an experiment to verify it. It's also lacking a lot of clarity - like how these things could actually happen. Just saying it happened is meaningless. Seems like you could test that by taking single cells and seeing if this could really happen. Good luck!

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