A new Tree of Life (Evolution)

by xeno6696 @, Sonoran Desert, Wednesday, June 06, 2012, 14:27 (4313 days ago)

Biology makes sense only in the light of evolution...-and Biology only makes sense in the light of computation:- http://www.nytimes.com/2012/06/05/science/open-tree-of-life-project-draws-in-every-twig...

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\"Why is it, Master, that ascetics fight with ascetics?\"

\"It is, brahmin, because of attachment to views, adherence to views, fixation on views, addiction to views, obsession with views, holding firmly to views that ascetics fight with ascetics.\"

A new Tree of Life; also a competitive tree

by David Turell @, Wednesday, June 06, 2012, 15:54 (4313 days ago) @ xeno6696

Biology makes sense only in the light of evolution...
> 
> and Biology only makes sense in the light of computation:
> 
> http://www.nytimes.com/2012/06/05/science/open-tree-of-life-project-draws-in-every-twig... different tree which touts convergence, which touts teleology:-http://www.mapoflife.org/browse/

A new Tree of Life; also a competitive tree

by xeno6696 @, Sonoran Desert, Thursday, June 07, 2012, 02:36 (4312 days ago) @ David Turell

I'm not sure why you think the two projects would be in competition... I'll put $100 that the cambridge tree is but a small data set that will be absorbed into the new tree...

--
\"Why is it, Master, that ascetics fight with ascetics?\"

\"It is, brahmin, because of attachment to views, adherence to views, fixation on views, addiction to views, obsession with views, holding firmly to views that ascetics fight with ascetics.\"

A new Tree of Life; also a competitive tree

by David Turell @, Thursday, June 07, 2012, 14:56 (4312 days ago) @ xeno6696

I'm not sure why you think the two projects would be in competition... I'll put $100 that the cambridge tree is but a small data set that will be absorbed into the new tree...-The Cambridge tree is a front for Simon Conway Morris, the theist world expert on Cambrian Explosion.

A new Tree of Life; getting bushier

by David Turell @, Monday, June 15, 2015, 18:27 (3209 days ago) @ David Turell

New studies find more types of bacteria and Archaea:-http://phys.org/news/2015-06-newfound-groups-bacteria-tree-life.html-
"University of California, Berkeley, scientists have identified more than 35 new groups of bacteria, clarifying a mysterious branch of the tree of life that has been hazy because these microbes can't be reared and studied in the lab.
 
"The new groups make up more than 15 percent of all known groups or phyla of bacteria, the scientists say, and include the smallest life forms on Earth, microbes a mere 400 nanometers across. The number of new bacterial phyla is equal to all the known animal phyla on Earth.-"The scientists, who recently also identified nine new groups of microbes known as Archaea, see these new additions to life on Earth as a sign that the accepted tree of life - a division into the three domains of eukaryotes, which includes animals and plants, bacteria and Archaea - needs to be revised.-"All life is divided into three domains, though everything we see around us is from only one of them: the eukaryotes, or organisms that have nuclei in their cells. Within the eukaryotes there are about 35 animal phyla - the phylum Chordata includes humans and all other vertebrates - 12 plant phyla and a few fungi. The microscopic bacterial domain has been much fuzzier because some organisms detected widely in the environment fail to grow in culture like other bacteria.-"By some estimates there are 100 bacterial phyla, though only 29 have representatives that will grow in culture. The new discovery allowed the team not only to define about a third of all bacterial phyla but, thanks to the nearly complete genomes, to characterize their lifestyles.-"'People have seen these bacteria in surveys of many different environments all over the planet, so we've known that they are there, and that they are fairly ubiquitous," Brown said. "What we didn't know is what the organisms were and what they were capable of doing."-"About half of all the genes in these 35-plus phyla are new and unlike other known genes. The recognizable genes suggest that most of the bacteria use a simple process of fermentation to make the energy they need, instead of using aerobic or anaerobic respiration like many other bacteria. They also have unusual ribosomes, the multi-protein machines that translate genetic instructions into proteins. In fact, routine genomic scans would not detect them because of their distinctive 16S ribosomal RNA genes. The UC Berkeley team found that some of the bacteria have very rare inserts, called introns, in genes coding for 16S ribosomal RNA, which make them invisible to current detection techniques.-"'We found that all of these have at least a couple of unusual ribosomal features, and many are missing ribosomal proteins that are thought to be either universal across the tree of life or in all of bacteria," Banfield said.-"'The unusual ribosomes, the small genomes - between 600 and 1,100 genes - the inability to synthesize amino acids and nucleotides, and a consistent metabolic story really connects these bacteria together in a pretty surprising way," Brown said."

A new Tree of Life; getting bushier and more complex

by David Turell @, Tuesday, June 23, 2015, 15:27 (3201 days ago) @ David Turell

More information on a new group of bacteria, unknown until recently, which can metabolize uranium:-http://phys.org/news/2015-06-subsurface-discovery-tree-life.html-"Last week a study published in Nature pulled the veil on a branch of the bacterial tree of life that has evaded detection for nearly a century and a half. The study, led by Christopher Brown, who is a PhD candidate in microbial biology at the University of California in Berkeley, used cutting edge genome sequencing and savvy bioinformatics techniques to make this remarkable discovery.-"It all started at an abandoned uranium milling site on the banks of the Colorado River in a town called Rifle. This location, contaminated with toxic byproducts of uranium milling, has been a test ground for researchers experimenting on how microbes can be harnessed to bioremediate or clean the environment.-"Previously, researchers found that when naturally occurring microbes were supplied with a food source—the simple carbon compound acetate—a fortuitous biochemical reaction ensued. When stimulated to grow, a certain group of bacteria utilized the soluble uranium present in the soil and converted it to an insoluble form. Once insoluble, the uranium would be less apt to flow through groundwater and into the adjacent Colorado River.-"These bacteria cannot be grown in lab cultures. To further complicate things, it is predicted that between 50-100 percent of bacteria in some of the groups they discovered would be completely missed using the standard molecular techniques.-"Currently the tree of life is divided into three kingdoms. Bacteria and Archaea are two branches, each composed solely of unicellular organisms. The third kingdom is Eukarya, which encompasses all multicellular life forms and some unicellular microbes as well.-"The finding of this paper "represents a substantial modification of the tree of life," corresponding author Jill Banfield said in a statement. "These new major features on the tree of life mean that it probably won't be the simple three-domain view we have now," Banfield said."

A new Tree of Life; getting bushier and more complex

by David Turell @, Wednesday, July 29, 2015, 15:54 (3165 days ago) @ David Turell

Another article on the findings at Rifle, Colorado. 28 more phyla of tiny bacteria:-https://www.quantamagazine.org/20150728-at-tiny-scales-a-giant-burst-on-tree-of-life/-"The discovery of new organisms is fairly cut and dried: Either you've found one or you haven't. Cataloging organisms, fitting them into the tree of life, involves more judgment calls.-"The researchers divided the 789 organisms into 35 phyla — 28 of which were newly discovered — within the domain bacteria. They based the sorting on the organisms' evolutionary history and on similarities in the code on the organisms' 16S rRNA genes — those with at least 75 percent of their code in common went into the same phylum.-"With these new additions, there are now roughly 90 identified bacterial phyla. This is a lot more than there were a year ago, but also far fewer than the 1,300 to 1,500 phyla that microbiologists estimate we'll have once a complete accounting is finished. Recent advances in genetic sequencing and genome binning make Brown and Banfield optimistic, though, that it won't be long before we've mapped them all."

A new Tree of Life; getting bushier with moe bacteria

by David Turell @, Monday, April 11, 2016, 18:48 (2908 days ago) @ David Turell

Using DNA in organisms not able to be grown in the lab has widely expanded the groups of bacteria:-https://www.sciencedaily.com/releases/2016/04/160411124716.htm-"Researchers at the University of California, Berkeley, who have discovered more than 1,000 new types of bacteria and Archaea over the past 15 years lurking in Earth's nooks and crannies, have dramatically rejiggered the tree to account for these microscopic new life forms.-***-"The tree of life is one of the most important organizing principles in biology," said Jill Banfield, a UC Berkeley professor of earth and planetary science and environmental science, policy and management. "The new depiction will be of use not only to biologists who study microbial ecology, but also biochemists searching for novel genes and researchers studying evolution and earth history."-"Much of this microbial diversity remained hidden until the genome revolution allowed researchers like Banfield to search directly for their genomes in the environment, rather than trying to culture them in a lab dish. Many of the microbes cannot be isolated and cultured because they cannot live on their own: they must beg, borrow or steal stuff from other animals or microbes, either as parasites, symbiotic organisms or scavengers.-"The new tree, to be published online April 11 in the new journal Nature Microbiology, reinforces once again that the life we see around us -- plants, animals, humans and other so-called eukaryotes -- represent a tiny percentage of the world's biodiversity.-***-"'What became really apparent on the tree is that so much of the diversity is coming from lineages for which we really only have genome sequences," she said. "We don't have laboratory access to them, we have only their blueprints and their metabolic potential from their genome sequences. This is telling, in terms of how we think about the diversity of life on Earth, and what we think we know about microbiology."-"One striking aspect of the new tree of life is that a group of bacteria described as the "candidate phyla radiation" forms a very major branch. Only recognized recently, and seemingly comprised only of bacteria with symbiotic lifestyles, the candidate phyla radiation now appears to contain around half of all bacterial evolutionary diversity.-***-"Archaea were first added in 1977 after work showing that they are distinctly different from bacteria, though they are single-celled like bacteria. A tree published in 1990 by microbiologist Carl Woese was "a transformative visualization of the tree," Banfield said. With its three domains, it remains the most recognizable today.-***-"She and her team constructed a tree based on 16 separate genes that code for proteins in the cellular machine called a ribosome, which translates RNA into proteins. They included a total of 3,083 organisms, one from each genus for which fully or almost fully sequenced genomes were available.-"The analysis, representing the total diversity among all sequenced genomes, produced a tree with branches dominated by bacteria, especially by uncultivated bacteria. A second view of the tree grouped organisms by their evolutionary distance from one another rather than current taxonomic definitions, making clear that about one-third of all biodiversity comes from bacteria, one-third from uncultivable bacteria and a bit less than one-third from Archaea and eukaryotes."-Comment: With this diversity, planning for a guided evolution could e hidden in all this differing DNA.

A new Tree of Life; getting bushier with more bacteria

by David Turell @, Tuesday, April 12, 2016, 15:42 (2907 days ago) @ David Turell

Another article pointing out other areas where undiscovered life may be hiding:-http://www.nytimes.com/2016/04/12/science/scientists-unveil-new-tree-of-life.html?emc=edit_th_20160412&nl=todaysheadlines&nlid=60788861&_r=0-"It's a humbling thing to behold. All the eukaryotes, from humans to flowers to amoebae, fit on a slender twig. The new study supported previous findings that eukaryotes and archaea are closely related. But overshadowing those lineages is a sprawling menagerie of bacteria.-"Remarkably, the scientists didn't have to go to extreme places to find many of their new lineages. “Meadow soil is one of the most microbially complex environments on the planet,” Dr. Hug said.-"Another new feature of the tree is a single, large branch that splits off near the base. The bacteria in this group tend to be small in size and have a simple metabolism.-"Dr. Banfield speculated that they got their start as simple life-forms in the first chapters in the history of life. They have stuck with that winning formula ever since. (my bold)-"Brian P. Hedlund, a microbiologist at the University of Nevada, Las Vegas who was not involved in the new study, said that one of the most striking results of the study was that the tree of life was dominated by species that scientists have never been able to see or grow in their labs. “Most of life is hiding under our noses,” he said.-"Dr. Banfield predicted that the bacterial branches of the tree of life may not change much in years to come. “We're starting to see the same things over and over again,” she said.-"Instead, Dr. Banfield said she expected new branches to be discovered for eukaryotes, especially for tiny species such as microscopic fungi. “That's where I think the next big advance might be found,” Dr. Banfield said.-"Dr. Hug disagreed that scientists were done with bacteria. “I'm less convinced we're hitting a plateau,” she said. “There are a lot of environments still to survey.'”-Comment: These simplistic organisms may help explain the origin of life (note the bold statement)

A new Tree of Life; are there alien life here?

by David Turell @, Wednesday, April 13, 2016, 14:16 (2906 days ago) @ David Turell

An interesting article which says we need to look differently than for standard DNA:-https://aeon.co/essays/does-earth-have-a-shadow-biosphere?utm_source=Aeon+Newsletter&utm_campaign=60912bfe67-Daily_Newsletter_13_April_20164_13_2016&utm_medium=email&utm_term=0_411a82e59d-60912bfe67-68942561-"If multiple lines of life bubbled up on Earth and evolved separately from our ancient ancestors, we could discover alien biology without leaving this planet.-"The modern-day descendants of these ‘aliens' might still be here, squirming around with van Leeuwenhoek's microbes. Scientists call these hypothetical hangers-on the ‘shadow biosphere'. If a shadow biosphere were ever found, it would provide evidence that life isn't a once-in-a-universe statistical accident. If biology can happen twice on one planet, it must have happened countless times on countless other planets. But most of our scientific methods are ill-equipped to discover a shadow biosphere. And that's a problem, says Carol Cleland, the originator of the term and its biggest proponent.-***-"If you have a sample of soil,' she asked them, ‘how will you recognise what's in it?' The scientists rattled off the usual answers: slide it under a microscope, put it in a Petri dish, make millions of DNA copies, catalogue the genes. But that party line disturbed Cleland. ‘You couldn't detect anything that wasn't almost identical to familiar Earth life,' she said. Their methods assumed that all microbes have genetic material that works like ours. Isn't it possible, Cleland wondered, that life arose more than once here? If so, organisms from a second (or third) genesis would never turn up in our tests, because our tests are only meant to turn up familiar life. ‘But these organisms, if they exist, would leave traces in the environment,' Cleland says.-***-"Telling scientists to find a shadow biosphere is like asking a chimpanzee to add oil to a car: they don't know what they're looking for or what tools to use. Nevertheless, Cleland has some suggestions. First, look at life in places where life ‘shouldn't' be. Even the most sauna-happy microbes, called hyperthermophiles, wilt above 122° C. If we find anything living at 150° C, then there's a good chance they're not of our ilk. Send balloons into the upper atmosphere; scramble up to high plateaus; snowmobile to the South Pole; drive Land Rovers into the Atacama Desert; don end-of-world suits and venture into uranium mines. Remain alert for phenomena that make us say not ‘Eureka!' but ‘Huh, that's weird.' And then consider that their explanation might, in fact, be very, very weird.-***-"The discovery of life as we don't know it would hint that biology is a universal law, like physics and chemistry. .....A shadow biosphere - evidence that biology emerged more than once on Earth - suggests that biology emerges as a normal consequence of Goldilocks or just?right conditions, rather than being a mysterious lottery-ticket phenomenon.-***-"Today, if asked whether life concocts itself given the right conditions, many people would respond affirmatively. It's not a new idea. But concrete, complex proof that we are the predictable result of a predictable law would tip over our throne, once and for all."-Comment: On the other hand it might just support God's throne, as the final step in fine-tuning.

A new Tree of Life; another comprehensive article

by David Turell @, Saturday, April 16, 2016, 15:40 (2903 days ago) @ David Turell

This article has a great diagram of the new 'tree' which is not a tree at all:-http://www.theatlantic.com/science/archive/2016/04/the-tree-of-life-just-got-a-lot-weirder/477729/-"We visible organisms should be the small wedge. We're latecomers to Earth's story, and represent the smallest sliver of life's diversity. Bacteria are the true lords of the world. They've been on the planet for billions of years and have irrevocably changed it, while diversifying into endless forms most wonderful and most beautiful. Many of these forms have never been seen, but we know they exist because of their genes. Using techniques that can extract DNA from environmental samples—scoops of mud or swabs of saliva—scientists have been able to piece together the full genomes of organisms whose existence is otherwise a mystery.-"Using 1,011 of these genomes, Laura Hug, now at the University of Waterloo, and Jillian Banfield at the University of California, Berkeley have sketched out a radically different tree of life. All the creatures we're familiar with—the animals, plants, and fungi—are crowded on one thin branch. The rest are largely filled with bacteria.-***-“'This is humbling,” says Jonathan Eisen from the University of California, Davis, “because holy **#$@#!, we know virtually nothing right now about the biology of most of the tree of life.”-***-"From every organism in these samples, the team analyzed sixteen proteins that form part of the ribosome—a universal machine that's found in all living things and that makes other proteins. Every organism has its own version of these proteins, and as new species diverge from each other, their versions become increasingly different. So by comparing these sixteen proteins, Hug and Banfield could work out how closely related their various microbes were, and draw their tree of life.-***-"It has two main trunks—one full of bacteria and another comprised of archaea, a dynasty of single-celled microbes that look superficially similar but run on very different biochemistry. The eukaryotes—the domain that includes all animals and plants—are but a thin branch coming off the archaeal trunk. (This hints at a much broader debate about the origin of eukaryotes.-***-"There's also a grander answer: we are the first and only organisms in Earth's history with the capacity to find and understand the others. We've done a reasonable job with the tools we have, but it's clear that our understanding of life is so unfinished that it makes iceberg tips look complete. If we care about knowing our world, and our place in it, then our work is just starting."-Comment: Looking at purpose, one must understand how soil comes from lava. It is broken down by erosion, rain, lichens and bacteria, as simplistic geologic view. We eukaryotes live because of soil. A rocky Earth had to be prepared to be fertile Earth to give us plants as a major source of energy. This 3+ billion years of preparation for the multicellular seems like a good plan for me. God, after all, has all the time He wants.

A new Tree of Life; another comprehensive article

by David Turell @, Saturday, April 16, 2016, 19:14 (2903 days ago) @ David Turell

David: Comment: Looking at purpose, one must understand how soil comes from lava. It is broken down by erosion, rain, lichens and bacteria, as simplistic geologic view. We eukaryotes live because of soil. A rocky Earth had to be prepared to be fertile Earth to give us plants as a major source of energy. This 3+ billion years of preparation for the multicellular seems like a good plan for me. God, after all, has all the time He wants.-This paper shows further how bacteria prepared Earth for life by breaking down iron:-https://www.sciencedaily.com/releases/2016/04/160415125954.htm
 
"A pair of papers from a UW-Madison geoscience lab shed light on a curious group of bacteria that use iron in much the same way that animals use oxygen: to soak up electrons during biochemical reactions. When organisms -- whether bacteria or animal -- oxidize carbohydrates, electrons must go somewhere.-"Iron is the fourth-most abundant element on the planet, and because free oxygen is scarce underwater and underground, bacteria have "thought up," or evolved, a different solution: moving electrons to iron while metabolizing organic matter.-"These bacteria "eat organic matter like we do," says Roden. "We pass electrons from organic matter to oxygen. Some of these bacteria use iron oxide as their electron acceptor. On the flip side, some other microbes receive electrons donated by other iron compounds. In both cases, the electron transfer is essential to their energy cycles."-"Iron-metabolizing bacteria have been known for a century, Roden says, and were actually discovered in Madison-area groundwater. "Geologists saw organisms that formed these unique structures that were visible under the light microscope. They formed stalks or sheaths, and it turned out they were used to move iron."-"Roden and He are geobiologists, interested in how microbes affect geology, but the significance of microbes in Earth's evolution is only now being fully appreciated, Roden says. "Eyebrows rose when we contacted the Biotech Center three or four year ago to discuss sequencing: 'Who are these people from geology, and what are they talking about?' But we stuck with it, and it's turned into a pretty cool collaboration that has allowed us to apply their excellent tools that are more typically applied to biomedical and related microbial issues."-"These are fundamental studies, but these chemical transformations are at the heart of all kinds of environmental systems, related to soil, sediment, groundwater and waste water," says Roden. "For example, the Department of Energy is interested in finding a way to derive energy from organic matter through the activity of iron-metabolizing bacteria." These bacteria are also critical to the life-giving process of weathering rocks into soil. (my bold)-"Some of the iron-metabolizing bacteria appear quite early on the tree of life, making the studies relevant to discovering the origins of life, but the findings also have implications in the search for life in space, Roden says. "Our support comes from NASA's astrobiology institute at UW-Madison. It's possible that on a rocky planet like Mars, life could rely on iron metabolism instead of oxygen."-Comment: Note the bold. Bacteria made the Earth inhabitable

A new Tree of Life; a new eukaryote found

by David Turell @, Wednesday, November 22, 2017, 20:32 (2318 days ago) @ David Turell

Early one-celled eukaryotes have a nucleus to distinguish them from bacteria. A new branch is found, suggesting multicellularity might have several starting points:

https://www.the-scientist.com/?articles.view/articleNo/50995/title/A-Newly-Identified-S...

"The tiny organism—named Ancoracysta twista—is not only its own species, says lead author of the study, Jan Janouškovec, but “it represents a whole new lineage in the eukaryotic tree of life.”

"A. twista is about 10 micrometers long and moves by using its whip-like flagellum. It is named after its distinguishing feature—the “ancoracyst,” a gun-like organelle that it uses to “shoot” at and immobilize its prey, usually other flagellate species. Janouškovec, a molecular biologist at University College London, along with an international team of scientists, discovered A. twista in a sample collected from the surface of a brain coral in a tropical aquarium.

"The researchers realized that Ancoracysta represents its own lineage when phylogenetic models could not reconcile its genetic material with that of any existing lineages. Ancoracysta is a protist, a group of unicellular, eukaryotic organisms that sit at the root of the eukaryotic tree of life. For researchers such as Janouškovec, they are an opportunity to study how ancestral eukaryotes first acquired their characterizing features including chloroplasts and mitochondria.

"Biologists often look at the mitochondrial genomes of these primitive creatures and see how many genes they contain, to get an idea of how old they are in evolutionary terms. This stems from the endosymbiotic theory, in which an energy-generating cell was engulfed by an ancestral eukaryotic cell, and eventually assumed the role of producing energy for its host, becoming modern-day chloroplasts and mitochondria.

"Throughout the course of evolution, the smaller cell lost much of its own genes to its host’s nucleus, retaining only those strictly necessary for energy production. In line with this theory is a long-standing assumption that some eukaryotes that have large mitochondrial genomes are probably closer to the eukaryotic root than others, explains Janouškovec.

"This is why an obscure eukaryotic group known as the jakobids—which have particularly “gene-rich” mitochondria—represent one of the earliest branches in the eukaryotic tree, and reflect an ancestral state. Their mitochondria have about 60 protein-coding genes, while humans have 13.

"But Janouškovec’s discovery has thrown a spanner into the works, because A. twista’s mitochondria also have a large number of protein-coding genes, 47, but they’re not closely related to the jakobids at all. This suggests that the origin of eukaryotes might be a bit more complicated than previously thought. A. twista is “helping us get a bit closer to answering some of those questions,” Janouškovec tells The Scientist.

"Janouškovec’s study shows just how little we know about our own domain of life, in particular when it comes to protists. “When you think of microscopic algae, we understand them very well in general, but these [non-photosynthetic] flagellates we don’t understand at all, but they’re an important part of the whole ecosystem,” he says. "

Comment: Note these little guys have mitochondria. This is a next stage in development of cells that can become multicellular organisms. It seems we are finding a bush of them which fits God's pattern of evolving bushes of new forms as evolution advances.

A new Tree of Life; Archaea and Eukaryotes related?

by David Turell @, Tuesday, June 05, 2018, 15:29 (2123 days ago) @ David Turell

A new branch of Archaea has some genes that are Euykaryote genes:

https://www.the-scientist.com/?articles.view/articleNo/54649/title/Archaea-Family-Tree-...

“[Archaeal taxonomy is] kind of like the Wild West,” says Brett Baker, a microbial ecologist at the University of Texas at Austin. “There’s going to be a huge debate about how we define a phylum.”

The Asgard superphylum, described by Ettema, Baker, and their colleagues in 2017, is also generating some disagreement due to its implications for the evolution of eukaryotes. The research started out innocuously enough, as the scientists assembled the genomes of an archaeal group found in sediments near an Arctic deep-sea vent known as Loki’s Castle.5 But they saw something strange. “We started finding all these eukaryotic genes,” Ettema recalls, including genes that seemed to encode eukaryote-like cytoskeletal proteins, small GTPases, and the ESCRT machinery involved in membrane-based processes such as autophagy and lysosome-based protein degradation.6 These so-called “eukaryotic signature proteins” typically don’t have homologs in either bacteria or archaea, says Ettema. “I realized either this is something really interesting, or this is some freaky artifact.”

He and his colleagues tested the samples for evidence of true eukaryotes, such as their 18S rRNA, and came up empty-handed. Convinced that the microbes they identified were indeed archaea, the researchers reported their results in 2015, dubbing the new phylum Lokiarchaeota for the vent site.7 Since then, Ettema’s and Baker’s teams have found three sister phyla to Lokiarchaeota, all containing genes formerly thought to be specific to eukaryotes: the Thorarchaeota, found in the dark, tannic acid–stained White Oak River estuary of North Carolina;8 the Odinarchaeota, found in hot springs such as those in Yellowstone National Park;9 and the Heimdallarchaeota, discovered in marine sediments.9 The researchers grouped these together as the Asgard superphylum.

Based on their interrogations of the asgardians, Ettema, Baker, and colleagues concluded that these archaea fit neatly into the late Lynn Margulis’s longstanding hypothesis of endosymbiosis—the idea that eukaryotes arose when one microbe engulfed another. The Asgard archaea would seem to be descendants of the original host that swallowed a bacterium, and at that time already possessed some of the genes scientists would come to associate with eukaryotes. This contrasts with the older idea that archaea and eukaryotes sprang from a common ancestor and evolved as two distinct, parallel lineages. The Lokiarchaeota provided the turning point, says Ettema: “Suddenly we come up with this phylum that seems to turn everything around.” He notes that Lokiarchaeota’s name references not only the discovery site but also the Norse trickster god for that reason.

Eme, who works in Ettema’s lab, says she’s now analyzing about 60 new Asgard genomes, looking for more eukaryote-like features and trying to piece together how the group evolved. “Now that we have more representatives of each of the lineages . . . we are starting to be able to make more-confident claims,” she says. “There’s so much to understand from these archaea.”

Comment: If Archaea came first bacteria and Eukaryotes are their descendents

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