Cell biology Origin Of Life

At Science Daily: New research on the emergence of the first complex cells challenges orthodoxy

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In the beginning, there was boredom. Following the emergence of cellular life on earth, some 3.5 billion years ago, simple cells lacking a nucleus and other detailed internal structure dominated the planet. Matters would remain largely unchanged in terms of evolutionary development in these so-called prokaryotic cells — the bacteria and archaea — for another billion and a half years.

Then, something remarkable and unprecedented took place. A new type of cell, known as a eukaryote, emerged. The eukaryotes would evolve many complex internal modules or organelles, including the endoplasmic reticulum, the Golgi apparatus and the mitochondria, forming wildly diverse cell types — precursors to all subsequent plant and animal life on earth. Prokaryotic cells, which include bacteria and archaea, are structurally simple organisms, lacking the complex internal structure found in eukaryotes. All living plant and animal species today have their origins in the Last Eukaryotic Common Ancestor or LECA. The transition from prokaryote to eukaryote has remained a central mystery biologists are still trying to untangle.

How this crucial transition came to be remains a central mystery in biology.

The researchers explore in detail, the energy requirements of eukaryotic cells, which are on average, larger and more complex compared with prokaryotes. Their quantitative results stand in opposition to a reigning dogma, first put forward by biologists Nick Lane and Bill Martin.

Genesis to Revelation

The basic idea of Lane and Martin is that a cell’s developmental fate is governed by its supply of energy. Simple prokaryotes are mostly small and consist of single cells or small colonies and can subsist on more limited stores of energy to power their activities. But once a cell achieves sufficient size and complexity, it eventually reaches a barrier, beyond which such prokaryotes can not pass. Or so the theory has it.

According to this idea, a singular event in Earth’s history gave sudden rise to the eukaryotes, which then grew and diversified to occupy every ecological niche on the planet, from undersea vents to arctic tundra. This vast diversification occurred when a free-living prokaryotic cell acquired another tiny organism within the confines of its interior.

Through a process known as endosymbiosis, the new cell resident is taken up by this proto-eukaryote, supplying it with additional energy and enabling its transformation. The endosymbiont it has acquired would eventually develop into mitochondria — cellular powerhouses found only in eukaryotic cells.

Because all complex life today can be traced to a single eukaryotic branch of the evolutionary tree, it has been assumed that this chance endosymbiotic event, the acquisition of mitochondria, occurred once and only once during the entire history of life on Earth. This accident of nature is why we’re all here. Without mitochondria, the larger volume and complexity of eukaryotes would not be energetically viable.

Not so fast, the authors of the new study claim.

Crossing the borderlands

Schavemaker notes that while the distinction between prokaryotes and eukaryotes among organisms living today is obvious, things were murkier during the transition phase. Eventually, all the common traits of extant eukaryotes would be acquired, yielding an organism researchers refer to as LECA or the Last Eukaryotic Common Ancestor.

The new study explores the advent of the first eukaryotes and notes that instead of a hard boundary line separating them from their prokaryotic ancestors, the true picture is messier. Rather than an unbridgeable gulf between prokaryotes and eukaryotes in terms of cell volume internal complexity and number of genes, the two cell forms enjoyed considerable overlap.

The researchers investigate a range of prokaryotic and eukaryotic cell types to determine a) how cell volume in prokaryotes can eventually act to constrain a cell’s membrane surface area required for respiration, b) how much energy a cell must direct to DNA activities based on the arrangement of its genome and c) the costs and benefits of endosymbionts for cells of various volume.

It turns out that cells can grow to considerable volume and acquire at least some of the characteristics of complex cells while remaining primarily prokaryotic in character and without the presence of mitochondria.

LECA revisited

The new picture of early eukaryote evolution provides a plausible alternative to the mitochondria-first paradigm. Rather than evolution ushering in the age of eukaryotes with one grand gesture — the chance acquisition of a mitochondrial prototype, a series of tentative, gradual, step-wise changes over vast timespans ultimately produced complex cells packed with sophisticated internal structures and capable of explosive diversification.

Earlier research by Lynch and Marinov cited in the new study takes a somewhat more radical view, implying that mitochondria offered few if any benefits to early eukaryotes. The new study stakes out a more moderate position, suggesting that beyond a critical cell volume, mitochondria and perhaps other features of modern eukaryotic cells would have been necessary to satisfy the energy needs of large cells, but a range of smaller proto-eukaryotes may have done just fine without these innovations.

Hence, the transition to the mysterious LECA event may have been preceded by a series of organisms, which may have initially been mitochondria-free.

The new research also throws into question the timing of eukaryotic transition events. Perhaps the great transition began with the development of a eukaryotic cytoskeleton or other advanced structure. 

Much more research will be required to confidently place the series of events leading to fully-fledged eukaryotes in their proper sequence.

Full article at Science Daily

From the 2nd paragraph: “The eukaryotes would evolve many complex internal modules or organelles, including the endoplasmic reticulum, the Golgi apparatus and the mitochondria, forming wildly diverse cell types — precursors to all subsequent plant and animal life on earth. Prokaryotic cells, which include bacteria and archaea, are structurally simple organisms, lacking the complex internal structure found in eukaryotes.” To acknowledge the vast increase in specific, functional biochemical complexity accompanying the origin of eukaryotes and to not even mention the constraints on information gain by any natural processes (step-wise or otherwise) is to simply be whistling Dixie in the dark.

8 Replies to “At Science Daily: New research on the emergence of the first complex cells challenges orthodoxy

  1. 1
    martin_r says:

    In the beginning, there was boredom. Following the emergence of cellular life on earth, some 3.5 billion years ago, simple cells lacking a nucleus and other detailed internal structure dominated the planet.
    … Then, something remarkable and unprecedented took place. A new type of cell, known as a eukaryote, emerged.

    A classic Darwinian fairy tale … i like the wording … it sounds so dramatic and mysterious … Darwinists always were very talented story-tellers …

  2. 2
    bornagain77 says:

    As to: “some 3.5 billion years ago, simple cells lacking a nucleus and other detailed internal structure dominated the planet. Matters would remain largely unchanged in terms of evolutionary development in these so-called prokaryotic cells — the bacteria and archaea — for another billion and a half years.,,,”

    Although such a long period of stasis, i.e. a ‘billion and a half years’ contradicts their theory, Darwinists don’t seem to be overly concerned by this extremely long period of stasis for bacteria.

    But as Stephen Jay Gould stated when he put forth his ‘feather-ruffling’ theory of punctuated equilibrium, “stasis is data”. And ‘stasis’ is certainly the rule, not the exception, as far as bacteria are concerned.

    The Paradox of the “Ancient” (250 Million Year Old) Bacterium Which Contains “Modern” Protein-Coding Genes: Heather Maughan*, C. William Birky Jr., Wayne L. Nicholson, William D. Rosenzweig§ and Russell H. Vreeland ; – 2002
    “Almost without exception, bacteria isolated from ancient material have proven to closely resemble modern bacteria at both morphological and molecular levels.”
    http://mbe.oxfordjournals.org/...../19/9/1637

    Static evolution: is pond scum the same now as billions of years ago
    Excerpt: But what intrigues (paleo-biologist) J. William Schopf most is lack of change. Schopf was struck 30 years ago by the apparent similarities between some 1-billion-year-old fossils of blue-green bacteria and their modern microbial counterparts. “They surprisingly looked exactly like modern species,” Schopf recalls. Now, after comparing data from throughout the world, Schopf and others have concluded that modern pond scum differs little from the ancient blue-greens. “This similarity in morphology is widespread among fossils of [varying] times,” says Schopf. As evidence, he cites the 3,000 such fossils found;
    http://www.thefreelibrary.com/.....a014909330

    AMBER: THE LOOKING GLASS INTO THE PAST:
    Excerpt: These (fossilized bacteria) cells are actually very similar to present day cyanobacteria. This is not only true for an isolated case but many living genera of cyanobacteria can be linked to fossil cyanobacteria. The detail noted in the fossils of this group gives indication of extreme conservation of morphology, more extreme than in other organisms.
    http://bcb705.blogspot.com/200.....st_23.html

    Scientists discover organism that hasn’t evolved in more than 2 billion years – February 3, 2015
    Excerpt: Using cutting-edge technology, they found that the bacteria look the same as bacteria of the same region from 2.3 billion years ago — and that both sets of ancient bacteria are indistinguishable from modern sulfur bacteria found in mud off of the coast of Chile.
    http://www.sciencedaily.com/re.....104131.htm

    Researchers: Microbes Have Been “At An Evolutionary Standstill” For 175 Million Years – April 9, 2021
    Excerpt: Using advanced tools that allow scientists to read the genetic blueprints of individual cells, the researchers examined the genomes of 126 microbes obtained from three continents. Surprisingly, they all turned out to be almost identical.
    “It was shocking,” Stepanauskas said. “They had the same makeup, and so we started scratching our heads.”
    Scientists found no evidence that the microbes can travel long distances, survive on the surface, or live long in the presence of oxygen. So, once researchers determined that there was no possibility the samples were cross-contaminated during research, plausible explanations dwindled.
    “The best explanation we have at the moment is that these microbes did not change much since their physical locations separated during the breakup of supercontinent Pangaea, about 175 million years ago,” Stepanauskas said. “They appear to be living fossils from those days. That sounds quite crazy and goes against the contemporary understanding of microbial evolution.”
    https://uncommondescent.com/intelligent-design/researchers-microbes-have-been-at-an-evolutionary-standstill-for-175-million-years/

    Geobiologist Noffke Reports Signs of Life that Are 3.48 Billion Years Old – 11/11/13
    Excerpt: the mats woven of tiny microbes we see today covering tidal flats were also present as life was beginning on Earth. The mats, which are colonies of cyanobacteria, can cause unusual textures and formations in the sand beneath them. Noffke has identified 17 main groups of such textures caused by present-day microbial mats, and has found corresponding structures in geological formations dating back through the ages.
    http://www.odu.edu/about/odu-p...../topstory1

    Scientists find signs of life in Australia dating back 3.48 billion years – Thu November 14, 2013
    Excerpt: “We conclude that the MISS in the Dresser Formation record a complex microbial ecosystem, hitherto unknown, and represent one of the most ancient signs of life on Earth.”… “this MISS displays the same associations that are known from modern as well as fossil” finds. The MISS also shows microbes that act like “modern cyanobacteria,”
    http://www.cnn.com/2013/11/13/.....ient-life/

    This extremely long period of stasis observed for bacteria is simply completely antithetical to Darwin’s theory, Especially considering that, “Bacteria,,, are ideal for this kind of study (of Darwinian processes), with generation times of 20 to 30 minutes, and populations achieved after 18 hours.”

    Scant search for the Maker
    Excerpt: But where is the experimental evidence? None exists in the literature claiming that one species has been shown to evolve into another. Bacteria, the simplest form of independent life, are ideal for this kind of study, with generation times of 20 to 30 minutes, and populations achieved after 18 hours. But throughout 150 years of the science of bacteriology, there is no evidence that one species of bacteria has changed into another, in spite of the fact that populations have been exposed to potent chemical and physical mutagens and that, uniquely, bacteria possess extrachromosomal, transmissible plasmids. Since there is no evidence for species changes between the simplest forms of unicellular life, it is not surprising that there is no evidence for evolution from prokaryotic to eukaryotic cells, let alone throughout the whole array of higher multicellular organisms.
    – Alan H. Linton – emeritus professor of bacteriology, University of Bristol.
    http://www.timeshighereducatio.....ode=159282

    In other words, if anything should ever give us empirical evidence that Darwinian evolution is true, or even feasible, it should be bacteria. And yet bacteria provide us with some of our strongest empirical evidence against Darwinian evolution.

    1 Thessalonians 5:21
    Test all things; hold fast what is good.

  3. 3
    Lieutenant Commander Data says:

    Billions of years are not helpful for evolution. It’s about the evolution of all life systems inside of a few minutes (life span of imaginary first bug) . If not then there is not even a single day of life on Earth. 😆

  4. 4
    martin_r says:

    good for Darwinists, that all these “remarkable and unprecedented” events always happen in deep past …. :))))))

  5. 5
    relatd says:

    “In other words, if anything should ever give us empirical evidence that Darwinian evolution is true, or even feasible, it should be bacteria. And yet bacteria provide us with some of our strongest empirical evidence against Darwinian evolution.”

    The goal is to keep repeating what boils down to a story. A fake story. Evolution is not a fact. Godless evolution is not a fact.

  6. 6
    Red Reader says:

    Yep, just assume “the emergence of cellular life on earth” and THEN begin to speculate about “something remarkable and unprecedented…”.
    I saw no value in reading past the first three sentences.

  7. 7
    Querius says:

    I got stuck on some hypothesized “simple” cell that musta predated all complicated cells that have been evolving for 3.8 billion years.

    Currently, the simplest cell belongs to Mycoplasma genitalium, a sexually transmitted bacterium with only 525 genes (or 580 kbp) as compared with over 20,000 genes in humans.
    https://pubmed.ncbi.nlm.nih.gov/31329090/

    Since M. genitalium is the simplest natural cell, I’m sure that Darwinists here will agree that life musta evolved from these simplest of cells. After all, evolution can only go from simple to complex.

    Since M. genitalium is a human STD, it makes sense that after 3.8 billion years, M. genitalium actually evolved humans as their exoskeletons, since their reproductive rate is many orders of magnitude greater than that of humans and therefore can evolve biological features for their hosts far more quickly than humans can alone.

    It should then come as no surprise that the Darwinists here should consider themselves as STDs.

    Don’t get mad, I’m just following “the science.”

    -Q

  8. 8
    Querius says:

    Well, apparently no objections at all from the Darwinists here! Bunch of STDs on legs. (wink)

    -Q

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