Evolution of life in the ocean changed 170 million years ago

Evolution of life in the ocean changed 170 million years ago
A calcified plankton sample dating back 95 million years. Credit: University of Plymouth

The ocean as we understand it today was shaped by a global evolutionary regime shift around 170 million years ago, according to new research.

Until that point, the success of organisms living within the marine environment had been strongly controlled by non-biological factors, including and climate.

However, from the middle of the Jurassic period onwards (some 170 million years ago), such as predator-prey relationships became increasingly important.

Writing in Nature Geoscience, scientists say this change coincided with the proliferation of -secreting plankton and their subsequent deposition on the .

They believe the rise of this plankton stabilised the chemical composition of the and provided the conditions for one of the most prominent diversifications of marine life in Earth's history.

The research was led by academics from the University of Plymouth's School of Geography, Earth and Environmental Sciences and School of Computing, Electronics and Mathematics, in cooperation with scientists from the University of Bergen in Norway, and the University of Erlangen-Nuremberg in Germany.

Ph.D. candidate Kilian Eichenseer, the study's lead author, explained the impact of calcifying plankton: "Today, huge areas of the ocean floor are covered with the equivalent of chalk, made up of microscopic organisms that rose to dominance in the middle of the Jurassic period. The chalky mass helps to balance out the acidity of the ocean and, with that balance in place, organisms are less at the mercy of short-term perturbations of ocean chemistry than they might have been previously. It is easier to secrete a shell, regardless of its mineralogy, if the ocean chemistry is stable."

The aim of the research was to test the hypothesis that the evolutionary importance of the non-biological environment had declined through .

Kilian Eichenseer and Dr Uwe Balthasar explain research suggesting evolution of life in the ocean changed 170 million years ago. Credit: University of Plymouth

Since its emergence more than 540 million years ago, multicellular life evolved under the influence of both the non-biological and the biological environment, but how the balance between these factors changed remained largely unknown.

Calcified seashells provide an ideal test to answer this question, as aragonite and calcite—the minerals making up seashells—also form non-biologically in the ocean.

In their study, the authors used the vast global fossil record of marine organisms that secreted calcium carbonate, which encompasses more than 400,000 samples dating from 10,000 years BC up to around 500 million years ago.

Using reconstructions of the temperature and the ocean water composition of the past, the authors estimated the proportion of aragonite and calcite that formed inorganically in the ocean in 85 geological stages across 500 million years.

Through a series of specially developed statistical analyses, this inorganic pattern of aragonite-calcite seas was then compared with seashell mineral composition over the same time.

The results show that up until the middle of the Jurassic period, around 170 million years ago, the ecological success of shell-secreting marine organisms was tightly coupled to their shell composition: organisms that secreted the mineral that was environmentally favoured had an evolutionary advantage.

However, the Earth-Life system was revolutionised forever by the rise of calcifying plankton, which expanded the production of calcium carbonate from continental shelves to the open ocean.

This ensured that the evolutionary impact of episodes of severe climate changes, and resulting ocean acidification, was less severe than comparable events earlier in Earth history.

Dr. Uwe Balthasar, Lecturer in Palaeontology, first published research exploring the dominance of aragonite and calcite in the in 2015. He said: "During the Earth's history there have been several major events that shaped the evolution of life on our planet, such as the five big mass extinctions or the radiation of complex animals during the 'Cambrian Explosion'. Our research identifies a previously overlooked event of this magnitude around 170 million years ago when the emergence of calcium carbonate-secreting plankton lifted constraints on the evolution of other marine organisms that we did not know existed. As a result, life in the ocean has diversified to levels far beyond what existed before."


Explore further

New study of plankton shells overturns decades-old understanding of their formation and chemistry

More information: Jurassic shift from abiotic to biotic control on marine ecological success, Nature Geoscience, DOI: 10.1038/s41561-019-0392-9, https://nature.com/articles/s41561-019-0392-9
Journal information: Nature Geoscience

Citation: Evolution of life in the ocean changed 170 million years ago (2019, July 1) retrieved 23 July 2019 from https://phys.org/news/2019-07-evolution-life-ocean-million-years.html
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Jul 01, 2019
Cool ideas, but "evolution" is just a myth: https://www.youtu...swvGoaPU

Jul 01, 2019
so zoot, let's see if i understand you.
"evolution" is just a myth"

because? you said so?
some religious loon abusing the internet told you so?

if i tell you, that person is a Martian?
by your own logic, that accusation must be accurate!

& i hope you are smart enough to understand, that posting that comment makes you a hypocrite?

unless you are communicating with us via your magical ouiija board?

i would presume you are using a computer or phone?
which technologies are based on the exact same sciences, methodology, empiricism & peer-reviewed confirmation of evidence.
As Evolutionary Theory & the Genetic Sciences.

using a computer or phone?
is to flat-out deny the validity of your proclaimed religious beliefs!

Jul 01, 2019
about the ideas in this article?
i would speculate that there is a high probability that 170 million years ago was the first of many land reptiles were re-adapting to ocean environments.

first reptiles, then dinosaurs, then avians & now mammals.

so, which came first?
the iguana or the plankton or the shellfish?
or? all together or separately?
perhaps something/s else, we haven't discovered and/or figured out yet??

i hink it is interesting,
that of all the different species that made the Sea Trek down to this World's oceans?
they all remained air-breathers!

for the energy turbo-boost free oxygen provides, i would presume?

Jul 01, 2019
Perhaps the higher levels of carbon dioxide in the atmosphere and ocean, allowed these organisms to flourish and help reduce the available carbon from the ecosystem. Ironically if they became too successful they would decrease the concentrations enough to cause global cooling, killing off life that couldn't deal with the change.

Jul 01, 2019
@Zoot
No it isn''t. Evolution followed the CREATION of the first single-celled organisms in the seas. The organisms EVOLVED while consuming the available materials such as aragonite and calcite, otherwise there would not have been other multicellular life forms that followed them and thrived also. Any religion that tells you that Evolution didn't and doesn't happen is a false religion. Evolution is/was a part of the PROGRAM that was set in motion by the Creator God over 500 million Earth years ago.
Before that Creation, there was only the atoms of the elements and molecules of minerals in the seas. Those minerals could not bring forth Life on their own.

Jul 02, 2019
And I challenge anyone to provide the evidence that minerals and any other form of Matter is able to bring forth a single-celled or multi celled life form that didn't already have a living or dead ancestor from whence it was descended. In other words, show me how life could possibly emanate from any of the elements in the Periodic Table, or any combination thereof, without outside help such as from a Creator.
I understand that it has been attempted several times, without success.

Jul 02, 2019
And I challenge anyone to provide the evidence that minerals and any other form of Matter is able to bring forth a single-celled or multi celled life form that didn't already have a living or dead ancestor from whence it was descended. In other words, show me how life could possibly emanate from any of the elements in the Periodic Table, or any combination thereof, without outside help such as from a Creator.
I understand that it has been attempted several times, without success.


fact is... THEY CAN'T AND never will... It would be MUCH MORE simple to claim that an F18 hornet self-assemble. ....Pfff

Jul 02, 2019
I challenge all of the scientists on this forum to take 1 hour of your time and look at the video posted above. It makes a LOT more logical sense than this article. Listen with an open mind. Then have an open discussion about it where people refrain from name-calling and belittling.

Jul 02, 2019
is this site really intended as a forum for stuporstitious lunacy?

cause if so?
i want to pass around a collection plate!

those drunken hooligan deities responsible for the stochastic mess we find ourselves?

have run up quite a bar bill!

& my Patroness
Coyote Trickster Goddess
only drinks the finest of French Champagnes.
none of that yank fizzypiss
or aussie bilgeswill!

ohh, & a truism for you american-taliban to offer
your minister:

"...The only contention
between the Wolf
& the Shepherd
is:
Which one of them
gets to eat the Lamb?"


Jul 02, 2019
So here we have scientists that has worked hard to uncover new facts that bear on the immediate and long term future of our planet. But comments are dominated by egotistical trolls of science, who are not concerned with what is and what can be. Just to underscore their meaninglessness trolling:

just a myth


Just a well known fact that is easily found when searched: https://en.wikipe...volution .

FYI, I work with it. Even if I start from scratch, it takes me a few minutes to observe the process by freely available software and data (from say NCBI). But of course a troll does not care for reality.

And I challenge anyone to provide the evidence that minerals and any other form of Matter is able to bring forth a single-celled or multi celled life form that didn't already have a living or dead ancestor from whence it was descended.


Superstitious (creationist) troll argument, which has nothing to do with observing and testing the fact. See above.

Jul 02, 2019
[And let me remind that the superstitious trolling is akin to astrology as of this century, since we now know it is equal (self)delusion. I am not going to repeat the evidence, but it is out there.

More relevant, we *also* managed to evidence years ago what these deluded people - irrelevantly, as per above - asked for, how live cells evolved over half alive cells from geological systems. Turns out we likely split from a geological sister system (not lineage, obviously) of alkaline hydrothermal vents: https://www.natur...l2016116 .

So, these trolls are even more rubbish than the ordinary anonymous trolls that pretend they aren't superstitious and don't ask questions we already answered, but just spout the argument of the five year's old: "nu-uh".]

Jul 02, 2019
torbjorn
we here at the Pro-Science Trolls & Human Progress Center
Wish to extend to you our thanks & admiration for your efforts at extolling the Real Sciences & protecting the Real Scientists

from the vicious attacks on reality by the deceitful stuporstitious fakirs of sanguinary primitive beliefs
& the plagiarist woomongers for fraudulent anti-science propaganda.

& before you accuse me of hyperbole?
{oh, go ahead,
you know you want to!}

just consider, that these agitprop campaigns come from the same Dark Web sites as the anti-vaxxers & climate-change deniers.

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