Algae explosion 650 million years ago is why we’re here today, ANU researchers say

Researchers say they have solved one of the biggest questions in science — how did humans and animals appear on Earth?

Surprisingly, the answer comes down to algae.

more…

Well it’s one of the reasons. There are obviously a good many others.

moss and lichen do a lot to provide conditions for collecting soils and covering rocky areas to support conditions conducive to more complex plant life.

I should read the paper rather than just the news before commenting but…

It seems to me they’ve got a bit of work to do yet to prove their case. The development of complex algae occurred during roughly the same period as the development of the first complex metazoans (or at least, the earliest known fossils thereof … an important distinction), but from that, there are at least four possibilities.

1/ The algal development led to the animal development
2/ The animal development led to the algal development
3/ They were both caused by something else (eg the nutrients released in the big melt)
4/ They were unrelated

>4/ They were unrelated

Seems the least likely.

Bubblecar said:

>4/ They were unrelated

Seems the least likely.

Included for completeness.

dv said:

I should read the paper rather than just the news before commenting but…

It seems to me they’ve got a bit of work to do yet to prove their case. The development of complex algae occurred during roughly the same period as the development of the first complex metazoans (or at least, the earliest known fossils thereof … an important distinction), but from that, there are at least four possibilities.

1/ The algal development led to the animal development
2/ The animal development led to the algal development
3/ They were both caused by something else (eg the nutrients released in the big melt)
4/ They were unrelated

The evidence suggests that land plants evolved from a line of filamentous green algae that invaded land about 410 million years ago during the Silurian period of the Paleozoic era. So much later than the 650 million years for the algae evolution.

PermeateFree said:

dv said:

I should read the paper rather than just the news before commenting but…

It seems to me they’ve got a bit of work to do yet to prove their case. The development of complex algae occurred during roughly the same period as the development of the first complex metazoans (or at least, the earliest known fossils thereof … an important distinction), but from that, there are at least four possibilities.

1/ The algal development led to the animal development
2/ The animal development led to the algal development
3/ They were both caused by something else (eg the nutrients released in the big melt)
4/ They were unrelated

The evidence suggests that land plants evolved from a line of filamentous green algae that invaded land about 410 million years ago during the Silurian period of the Paleozoic era. So much later than the 650 million years for the algae evolution.

Sure, but we’re not talking about the development of land plants.

dv said:

PermeateFree said:

dv said:

I should read the paper rather than just the news before commenting but…

It seems to me they’ve got a bit of work to do yet to prove their case. The development of complex algae occurred during roughly the same period as the development of the first complex metazoans (or at least, the earliest known fossils thereof … an important distinction), but from that, there are at least four possibilities.

1/ The algal development led to the animal development
2/ The animal development led to the algal development
3/ They were both caused by something else (eg the nutrients released in the big melt)
4/ They were unrelated

The evidence suggests that land plants evolved from a line of filamentous green algae that invaded land about 410 million years ago during the Silurian period of the Paleozoic era. So much later than the 650 million years for the algae evolution.

Sure, but we’re not talking about the development of land plants.

Was merely pointing out the time difference between the two.

Also, sorry to nitpick but:

“Researchers say they have solved one of the biggest questions in science — how did humans and animals appear on Earth?”

This has nothing to do with how humans appeared, an event that happened more than 600 million years later. I mean you can say that if the complex animals hadn’t arisen then we wouldn’t have humans, but you can say that about the badgers and the dragonflies. “How did dragonflies and animals appear on Earth?”

dv said:

Also, sorry to nitpick but:

“Researchers say they have solved one of the biggest questions in science — how did humans and animals appear on Earth?”

This has nothing to do with how humans appeared, an event that happened more than 600 million years later. I mean you can say that if the complex animals hadn’t arisen then we wouldn’t have humans, but you can say that about the badgers and the dragonflies. “How did dragonflies and animals appear on Earth?”

That’s what I hoped to imply in my first post.

Possibly algae appeared first?

possibly bacteria appeared first?

then possibly in this order

small plants

then insects

then small fish

then small animals small birds

then larger animals fish appeared

but in what order?

Tau.Neutrino said:

Possibly algae appeared first?

possibly bacteria appeared first?

then possibly in this order

small plants

then insects

then small fish

then small animals small birds

then larger animals fish appeared

but in what order?

AFAIUI plant and animal life was abundant and varied in the ocean before there was even algae on land.

dv said:

Also, sorry to nitpick but:

“Researchers say they have solved one of the biggest questions in science — how did humans and animals appear on Earth?”

This has nothing to do with how humans appeared, an event that happened more than 600 million years later. I mean you can say that if the complex animals hadn’t arisen then we wouldn’t have humans, but you can say that about the badgers and the dragonflies. “How did dragonflies and animals appear on Earth?”

From single cell to multi-celled microbes to more complex animals and plants, some of which colonised the land, eventually evolving to dragonflies, badgers and humans.

dv said:

Also, sorry to nitpick but:

“Researchers say they have solved one of the biggest questions in science — how did humans and animals appear on Earth?”

This has nothing to do with how humans appeared, an event that happened more than 600 million years later. I mean you can say that if the complex animals hadn’t arisen then we wouldn’t have humans, but you can say that about the badgers and the dragonflies. “How did dragonflies and animals appear on Earth?”

I was going to give it a D-. I guess if you are trying to compile a complete sequence from primordial sludge to modern humans this could be a missing piece of the story,

Tau.Neutrino said:

Possibly algae appeared first?
possibly bacteria appeared first?
then possibly in this order
small plants
then insects
then small fish
then small animals small birds
then larger animals fish appeared
but in what order?

Okay none of that is what this article is about but just to answer…
Algae appeared about 1.2 billion years ago, possibly more
Bacteria appeared maybe 4 billion years ago
Small but complex marine plants appeared about 1 billion years ago
Insects appeared about 400 million years ago
Small fish, some 540 million years ago
Small animals, well animals arose maybe 680 million years ago
Small birds: this is a tough one to date as the transition from dinosaur to bird is gradual, not sudden. Let’s say very roughly 120 million years ago.
Larger animals/fish: well this happened a few tens of millions of years after the smaller versions.

But:

This article is about the development of complex algae around 600 million years ago, and the uptick in the evolution of macroscopic complex fossil-making animals roughly in the same era. Vendiobionts and shit.

PermeateFree said:

dv said:

Also, sorry to nitpick but:

“Researchers say they have solved one of the biggest questions in science — how did humans and animals appear on Earth?”

This has nothing to do with how humans appeared, an event that happened more than 600 million years later. I mean you can say that if the complex animals hadn’t arisen then we wouldn’t have humans, but you can say that about the badgers and the dragonflies. “How did dragonflies and animals appear on Earth?”

From single cell to multi-celled microbes to more complex animals and plants, some of which colonised the land, eventually evolving to dragonflies, badgers and humans.

They should have had you as the copy editor.

party_pants said:

I was going to give it a D-.

Always too generous

Witty Rejoinder said:

Tau.Neutrino said:

Possibly algae appeared first?

possibly bacteria appeared first?

then possibly in this order

small plants

then insects

then small fish

then small animals small birds

then larger animals fish appeared

but in what order?

AFAIUI plant and animal life was abundant and varied in the ocean before there was even algae on land.

I have really no idea when things first appeared.

The transition from chemicals to life could have been slow or fast.

Maybe the breakdown of rock into soil had something to do with it.

And millions of years of heat from the sun.

Certainly chemicals, gases, lightning, water and surface pressure etc.

dv said:

party_pants said:

I was going to give it a D-.

Always too generous

I also give out certificates for trying

dv said:

PermeateFree said:

dv said:

Also, sorry to nitpick but:

“Researchers say they have solved one of the biggest questions in science — how did humans and animals appear on Earth?”

This has nothing to do with how humans appeared, an event that happened more than 600 million years later. I mean you can say that if the complex animals hadn’t arisen then we wouldn’t have humans, but you can say that about the badgers and the dragonflies. “How did dragonflies and animals appear on Earth?”

From single cell to multi-celled microbes to more complex animals and plants, some of which colonised the land, eventually evolving to dragonflies, badgers and humans.

They should have had you as the copy editor.

Most kind.

dv said:

Tau.Neutrino said:

Possibly algae appeared first?
possibly bacteria appeared first?
then possibly in this order
small plants
then insects
then small fish
then small animals small birds
then larger animals fish appeared
but in what order?

Okay none of that is what this article is about but just to answer…
Algae appeared about 1.2 billion years ago, possibly more
Bacteria appeared maybe 4 billion years ago
Small but complex marine plants appeared about 1 billion years ago
Insects appeared about 400 million years ago
Small fish, some 540 million years ago
Small animals, well animals arose maybe 680 million years ago
Small birds: this is a tough one to date as the transition from dinosaur to bird is gradual, not sudden. Let’s say very roughly 120 million years ago.
Larger animals/fish: well this happened a few tens of millions of years after the smaller versions.

But:

This article is about the development of complex algae around 600 million years ago, and the uptick in the evolution of macroscopic complex fossil-making animals roughly in the same era. Vendiobionts and shit.

Ok, thanks for that.

I was unsure which appeared first.

Tau.Neutrino said:

Algae explosion 650 million years ago is why we’re here today, ANU researchers say

Researchers say they have solved one of the biggest questions in science — how did humans and animals appear on Earth?

Surprisingly, the answer comes down to algae.

more…

I also haven’t read the article yet.
Please keep in mind that “algae” is not a related group of organisms but refers to a huge unrelated group of aquatic photosynthetic organisms.

There’s no question that the cyanobacteria (ie. blue green algae) played a huge role in the development of plants (directly incorporated into chloroplasts) and animals (by filling the atmosphere with oxygen). Also, when last I heard, the oldest complete cell microfossil was a cyanobacterium.

The researchers unearthed the answer to that question in ancient sedimentary rocks from central Australia.

With new technology they were able to look at the rocks differently, removing contaminants that had previously hidden molecules.

By crushing the rocks, they could extract ancient molecules.

“What we found was quite spectacular and was really, totally unexpected,” Professor Brocks said.

“We found out that these molecules of more complicated algae increased in a big burst around 650 million years ago.”

And being able to pinpoint that timeframe was the key to their breakthrough.

“The reason why that is so exciting is it is just before animals appeared and also exciting because it happened after the biggest climatic catastrophe in Earth’s history.”

Melting ‘Snowball Earth’ triggered algae explosion

That climatic catastrophe was a global thawing of what Professor Brocks calls a “Snowball Earth”.

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Which begs the question “which algae”?

The full article in Nature shines a light on which chemicals. Steroids (steranes) with up to 30 carbon atoms. The distribution is compared with that in “a Phanerozoic oil”.

Looking up what the heck a “sterane” is, it seems to be a chemical derived from cholesterol. So whet they’re looking for here is the presence of cholesterol and similar chemicals in rocks.

Are these found in algae? Yes. “Eleven species of Caribbean marine algae (red, green, and brown) were investigated for their cholesterol content. All of them were found to contain this sterol. Consistent with previously reported results, all five red algae contained large quantities of cholesterol. However, the two brown algae and three of the four green algae in our study also contained significant quantities of cholesterol.”

“In eukaryotes, sterols such as cholesterol modulate membrane order, yet they are not typically found in prokaryotes. The structurally similar bacterial hopanoids exhibit similar ordering properties as sterols in vitro”.

———-

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature23457.html

The transition from dominant bacterial to eukaryotic marine primary productivity was one of the most profound ecological revolutions in the Earth’s history, reorganizing the distribution of carbon and nutrients in the water column and increasing energy flow to higher trophic levels. But the causes and geological timing of this transition, as well as possible links with rising atmospheric oxygen levels1 and the evolution of animals, remain obscure.

Here we present a molecular fossil record of eukaryotic steroids demonstrating that bacteria were the only notable primary producers in the oceans before the Cryogenian period (720–635 million years ago). Increasing steroid diversity and abundance marks the rapid rise of marine planktonic algae (Archaeplastida) in the narrow time interval between the Sturtian and Marinoan ‘snowball Earth’ glaciations, 659–645 million years ago. We propose that the incumbency of cyanobacteria was broken by a surge of nutrients supplied by the Sturtian deglaciation.

The ‘Rise of Algae’ created food webs with more efficient nutrient and energy transfers, driving ecosystems towards larger and increasingly complex organisms. This effect is recorded by the concomitant appearance of biomarkers for sponges and predatory rhizarians, and the subsequent radiation of eumetazoans in the Ediacaran period.

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Well, that all makes sense, unless of course the rise in primitive cholesterol levels was due to either animals or to the bacteria that were the common ancestors of animals and plants.