Tiny Microbes and the Tree of Life, Big Aliens

Small critters: The University of California, Berkeley, press release calls them "bacteria," but scientists may decide that they should get another label. These tiny microorganisms aren't quite like anything else that's had its DNA analyzed before, so textbooks may need to be rewritten in a few years.

Big aliens: Ever since reporters garbled a 1950s UFO sighting, "little green men" has meant "space alien." We still don't know whether there's life, intelligent or otherwise, elsewhere: but a scientist says that if we've got neighbors, they're probably bigger than we are.

1. Rearranging the Tree of Life
   • Previously-Unknown Genes
2. Earth, Space Aliens, and Perspective
   • Size, Brains, and Speculation

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It's a Big Universe

I think that we definitely are alone in the universe: or have neighbors. Right now, we don't know. (November 7, 2014; June 27, 2014)

If we do have neighbors, I'd be astounded if the usual SETI (Search for ExtraTerrestrial Intelligence) assumptions are valid: that our neighbors use modulated electromagnetic transmissions for long-distance communications; and are as incorrigibly chatty as we are. (June 27, 2014)

It's been a while since I went over this, so —

The universe started about 13,798,000,000 years back. Earth formed 4,540,000,000 years ago: give or take about 4,540,000. So far, the oldest traces of life are 3,500,000,000 to 3,700,000,000 years old.

We've been making stone tools for about 2,600,000 years, maybe longer.

We discovered radio waves about 150 years back, and began using them for communications a few decades after that.

Blink, and You'll Miss It

Let's compare how many years before today a few key things happened:

• 13,798,000,000 - universe starts
• 4,540,000,000 - Earth forms
• 3,500,000,000 - life starts
• 2,600,000 - Oldowan stone tools
• 151 - Maxwell's radio equations
• 119 - Marconi's wireless telegraphy

On this scale, 151 years is a 'blink and you'll miss it' sort of interval.

If our neighbors started only a million years before or after we did, they'd be almost exactly our age, in a way: 1/13,798^th the age of the universe, or 1/4,540^th Earth's age.

If they started making stone tools 1,600,000 years ago, and develop new tech about as fast as we do: their current cutting-edge tech includes almond-shaped stone hand axes. They'll find out about radio waves in another 999,885 years - call it 1,000,000.

On the other hand, maybe they started making stone tools 3,600,000 years back, learned about radio waves while we were learning how to use fire, and are currently doing whatever we'll be doing 1,000,000 years from now.

I don't know what tech we'll have by then: but I'd be surprised and disappointed if talking drums, slit gongs, and the Inmarsat network are the ultimate communication technologies. Another set of surprises may be brewing, and I've discussed quantum entanglement before. (May 3, 2013)

Maybe talking about people being around a million years from now seems odd. Around the time I graduated from high school, the silly notion that science and technology will solve all our problems was being replaced by the equally-silly fear that humanity is doomed.

There's the perennial 'end times Bible prophecy,' too, and that's another topic. (April 19, 2015; January 25, 2015)

My guess is that we'll prove to be at least as durable as rats and scorpions. We're certainly smarter. (January 30, 2015; November 29, 2013)

Accepting Reality

Humility, Catholic style, is accepting reality¹ — including scientific discoveries, those invitations to "even greater admiration for the greatness of the Creator." It's also about remembering that God's God and we're not. (Catechism of the Catholic Church, 283, 2540, 2559)

Taking care of this world is part of our job. (Catechism, 373, 2415, 2456)

We need tech to get just about anything done, so it's good that studying this world and developing new tools is part of being human. (Catechism, 2292-2296)

Created in the image of God, we're rational creatures "little less than a god:" with the power and frightening responsibilities that come with our nature. (Genesis 1:26-27, 2:7; Psalms 8:6; Catechism, 355-373, 2402, 2415-2418, 2456)

Forgetting that "little less than a god" isn't "God" gets us in trouble. I've been over that before. (March 29, 2015; December 12, 2014)

But, as I keep saying, Thinking is not a sin. (Wisdom 7:17; Catechism, 35, 159, 1730-1738)

One more thing, about Sacred Scripture — As a Catholic I'm "forcefully and specifically" urged to read the Bible, often. (Catechism, 101-133)

That's not the same as assuming that the Bible was written by a literal-minded American (July 13, 2014)

"Little" Green Men?

Getting back to space aliens, I'm not sure why little green men caught on so quickly. Hauling a net through my memory, I dredged up recollections of silver lamé spandex, tacky sets, and Kronos.

Okay, not all space aliens were runts — although Kronos was a giant robot, not a live alien; the movie was really 'relevant;' and that's yet another topic.

I'll be talking about Fergus Simpson's speculations on how big our non-human neighbors might be, and what sort of planet they'd be from, later.

Before discussing tiny bacteria-like things and big hypothetical space aliens, I'll ramble on about how big humans are.

Shrews, Blue Whales, and Us

Size isn't everything, but it's impressive.² Maybe that's why lots of folks go to see a zoo's elephant, but not many line up to watch the German cockroach. Then again, not many folks find elephants in their pantry.

Elephants are big, but they're not the biggest animal around. That's the blue whale. Gravity limits how big a land animal can be: which is something Fergus Simpson discusses, but I probably won't. Not this time around.

Some dinosaurs were lots bigger than elephants, but they're not around any more. The big ones avoided equatorial areas for a long time, for reasons that may or may not be what some scientists suggest. Yet again more topics.³

I'll take a quick, not terribly scientific, look at some of today's mammals: mostly how much they weigh, in grams. These numbers are approximate:

• 170,000,000 - blue whale
• 5,000,000 - African elephant (male)
• 2,500,000 - African elephant (female)
• 500,000 - Kodiak bear (male)
• 270,000 - Kodiak bear (female)
• 80,000 - human (male)
• 60,000 - human (female)
• 4,500 - domestic cat
• 2 grams - Etruscan shrew

It looks like we're really small: but this list leaves out a lot of animals. The smallest insect, for example, is probably the Dicopomorpha echmepterygis, measuring 139 micrometers long. A single-celled Paramecium is 50 to 330 micrometers long, depending on species.

Besides, although we're about 169,950,000 grams lighter than a blue whale, we're 1/3,400^th as massive. That's still pretty small.

On the other hand, an Etruscan shrew is 1/25,000^th as massive as an average human — so we're way bigger than a shrew than we're smaller than a whale: on a logarithmic scale.

That might be more important, subjectively, since I suspect that most folks find it easier to think of quantities in terms of fractions.

Think about it: picking up a six-pound object and a three-pound object, is someone more likely to think 'ah! this is 1.36 kilograms heavier than the other?' Or 'this one's twice as heavy as the other?'

My guess it's the 'twice as heavy' option.

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1. Rearranging the Tree of Life

(From Banfield group, via Phys.org, used w/o permission.)
("The new groups of bacteria (CPR) greatly expand the known and characterized phyla (top). These and previously reported new groups of Archaea (DSPANN) show that the Tree of Life is oversimplified."
(Phys.org))

"Newfound groups of bacteria are mixing up the tree of life"
Robert Sanders, Media Relations, Berkeley (June 15, 2015)

"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.

" 'This is a new view of the tree of life,' said lead author Jill Banfield, a professor of earth and planetary science and of environmental science, policy and management. 'These new groups of bacteria and Archaea are changing our understanding of the number and arrangement of branches on the tree of life.'..."

A tip of the hat to Vittoria Patti, on Google Plus, for the heads-up on this news.

When I was in high school, I learned that there were plants and animals, that fungi were either non-photosynthetic plants or something else, and that bacteria didn't quite fit into any of those categories. There were viruses, too.

Folks teaching science and writing textbooks weren't trying to confuse us. Scientists were learning that differences between prokaryotes, organisms without cell nuclei, and eukaryotes, organisms with nuclei, were important.

The old Aristotelian/Theophrastotelian classification of living things into plants and animals has been reviewed and revised a lot since Ernst Haeckel suggested calling some critters that weren't much like plants or animals protista.

Obviously, we didn't have all the answers then. We still don't, but we've learned a bit more.

Carl Woese defined Archaea as a third domain or kingdom for life in 1977: introducing the three-domain system we have now. It's a classification system that divides cellular life into archaea, bacteria, and eukaryote domains.

Archaea and bacteria don't have a cell nucleus. Archaea don't have organelles, either: specialized little sacks inside a cell. Neither do bacteria, for the most part.

Archaea and bacteria look alike, sort of, but archaea are more like eukaryotes, genetically, and have some of the same metabolic pathways we do.

Eukaryotes are organisms with a nucleus and other organells in each cell. Well, most cells.

Erythrocytes, red blood cells, in mammals don't have nuclei or other organelles. The same goes for Batrachoseps salamanders and Maurolicus fish, and that's still another topic.

Plants, animals, and fungi are eukaryotes. We don't know much about the evolution of fungi, since they're easily recycled. The earliest fossil that looks like it might be a fungus is about 1,430,000,000 years old. The earliest fossil fungi that are definitely fungi are in the Rhynie chert, a fossil bed formed some 410,000,000 years ago.


(From Ron Blakey, Paleogeography Library, Colorado Geosystems, Inc., used w/o permission.)
(Earth, about 400,000,000 years back.)

Another thing — the "tree of life" mentioned in the article isn't Yggdrasil, the immense tree in Norse cosmology. Its a metaphor biologists use when discussing how organisms relate to each other. Saying "tree of life" is probably easier than something like "hierarchical affinity diagram."

Previously-Unknown Genes

(From Berkeley Labs, used w/o permission.)
(A cryo-electron tomography image from Berkeley Labs, showing the internal structure of an ultra-small bacteria cell. The scale bar is 100 nanometers.
(Berkeley Labs))

"...'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,' [Berkeley graduate student Christopher] 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.

" '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...."
(Robert Sanders, Media Relations, Berkeley)

Before the 20th century, when we developed molecular genetics as a tool for studying organisms, scientists studied critters by observing how they look and act. For the most part.

Now that we can study genetic code, too, we're learning a lot more about life's long story. For one thing, life is very modular on the sub-cellular level. (February 20, 2015; January 9, 2015)

That's one reason that these newly-analyzed microcritters are so exciting. About half the genes in the 35-plus phyla studied are new, and not like other known genes. What that means, and how these critters fit into the rest of Earth's life — is something we'll be discovering.

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2. Earth, Space Aliens, and Perspective

(From Metro, used w/o permission.)
("Alien not to scale"
(Metro))

"If aliens exist then they’re absolutely massive, scientist claims"
Ollie McAteer, Metro.co.uk (April 7, 2015)

"The alien of today would leave Marvin the Martian quaking in his tiny space boots.

"That’s because, according to new research, they’re absolutely massive.

"A study by cosmologist Fergus Simpson, a scientist at the University of Barcelona, concludes that extraterrestrials could weigh up to 300kg (nearly 50 stone), if they exist.

"The theory behind it was spawned through observations of our own planet.

"Here on Earth, larger animals need more resources and are therefore less abundant. Earth is considered a planet dominated by smaller lifeforms – including humans...."

The tone of this Metro, UK, article is thoroughly tongue-in-cheek; and its facts not entirely accurate; but Fergus Simpson's research is real.

"Huge" may be a tad misleading, though — 300 kilograms is about 661 pounds, more than a human: but far from the largest critters on Earth. Simpson didn't say "up to" either, and I'll get back to that.

An American bison, for example, weighs between 318 and 1,000 kilograms; a large Gemsbok weighs 300 kilograms; and so does a six-year-old polar bear. Adult polar bears weigh up to 600 kilograms.

My hat's off to Fergus Simpson, the scientist whose paper sparked that news item, for starting his paper with this insight:

"Earth-like planets are expected to provide the greatest opportunity for the detection of life beyond the Solar System. This notion stems from an assumption that the Earth constitutes a simple random sample amongst inhabited planets...."
("The Nature of Inhabited Planets and their Inhabitants," Fergus Simpson, University of Barcelona (March 27, 2015))

Later, he makes the perhaps-obvious point that there's a big difference between the mass of an entire species, and that of an individual.

An individual ant, for example, is much smaller than a human, but the world's living ants as a whole weigh something like 30 to 300 million tonnes. That's close to 350 million tonnes for humans, but a whole lot less than the 1,000 million tonnes of cyanobacteria. (Biomass (ecology), Global biomass, Wikipedia)

He also mentioned Kleiber's law, a rule-of-thumb relationship between an animal's size and its metabolism.

I'm not sure how either relates to how big people with our sort of intelligence might be, although it's important in figuring out how many individuals of various sizes a given habitat is likely to support.

Finally, although the article said Simpson figured space aliens would be "up to" 300 kilograms — Simpson wrote:

"...The median per-individual body mass is calibrated to 70kg, representing the human species ... which implies a typical advanced species of around 314kg...."
("The Nature of Inhabited Planets and their Inhabitants," Fergus Simpson)

In this context, median means the number halfway between the highest and lowest value: pretty much. So what Simpson was saying was that your typical space alien might be around 314 kilograms — about half bigger, another half smaller. That's pretty close to 300, though.

More:

• "The Nature of Inhabited Planets and their Inhabitants"
  Fergus Simpson, University of Barcelona (Submitted March 15, 2015; published March 27, 2015)
  (From arxiv.org/abs/1503.07804v1 (June 15, 2015))

Size, Brains, and Speculation

Fergus Simpson carefully points out Earth is the only planet we know about that supports life, intelligent and otherwise.

That's a really small sample for speculation about life's limits and what our neighbors might be like: if we have neighbors.

Getting back to ants, size, intelligence, and speculation, recently-published research found that mushroom bodies in some social wasps are smaller than those structures in solitary wasps.

These mushroom bodies are structures in the brains of insects, other arthropods, and some annelid worms. They're important for olfactory memory and learning in most insects: including, presumably, wasps.

Social mammals generally have bigger brains than solitary ones, these researchers say. The working assumption is that cooperating with others takes more brainpower than working alone.

Oddly enough, social wasps have smaller mushroom bodies than their solitary counterparts. The scientists speculated that social wasps might use "distributed cognition:" pooling their brainpower:

• "Distributed cognition and social brains: reductions in mushroom body investment accompanied the origins of sociality in wasps (Hymenoptera: Vespidae)"
  Sean O'Donnell, Susan J. Bulova, Sara DeLeon, Paulina Khodak, Skye Miller, Elisabeth Sulger, Proceedings B, Royal Society (Received April 7, 2015; accepted May 21, 2015; published June 17, 2015)

That doesn't mean that wasps are people, but I think it hints that if we do have neighbors in the universe — they may not be human. Not even close.

My views about:

• "Humility, Science, and Accepting Reality"
  (March 29, 2015)
  Particularly
  
  • Scientists, Ethics, and Horrors: Imagined and Real
  • Order, Beauty, and Using our Brains
  • Science and Humility
• "Dawn's Arrival at Ceres; Sims and 'Chaos' "
  (March 13, 2015)
  Particularly
  • Earth: 'the Perfect Place for Life....' — or Maybe Not
• " 'Organic," "Wow!' — and Double Planets"
  (November 28, 2014)
  Particularly
  
  • Life in the Universe and Using Our Brains
  • Philae: Rich Data from a Bouncing Lander
• "Harpooning the 'Rubber Duck' Comet; Public Safety — and Space Aliens"
  (November 7, 2014)
  Particularly
  
  • Faith, Philosophy, and Space Aliens
    • Assumptions and Knowledge
    • Fear and Hope
    • "...It's a Mighty Sobering Thought"
    • Speculation and Mr. Chuckles
• "Life in the Universe, and Titan's Disappearing 'Island' "
  (June 27, 2014)
  Particularly
  
  • Star Trek, Scientists, and Catalogs of Known Worlds
  • Alone in the Universe: Or Not
  • Klaatu, Angels, and Getting a Grip
  • Eldritch Horrors and SETI
  • Living with Reality, Finding "Wonderful Things"

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¹ About humility, and thinking:

"CONSCIENCE: The interior voice of a human being, within whose heart the inner law of God is inscribed. Moral conscience is a judgment of practical reason about the moral quality of a human action. It moves a person at the appropriate moment to do good and to avoid evil (1777–1778). An examination of conscience is recommended as a preparation for the reception of the Sacrament of Penance (1454)."
(Catechism of the Catholic Church, Glossary, C)

"HUMILITY: The virtue by which a Christian acknowledges that God is the author of all good. Humility avoids inordinate ambition or pride, and provides the foundation for turning to God in prayer (2559). Voluntary humility can be described as 'poverty of spirit' (2546)."
(Catechism of the Catholic Church, Glossary, H)

"SIN: An offense against God as well as a fault against reason, truth, and right conscience. Sin is a deliberate thought, word, deed, or omission contrary to the eternal law of God. In judging the gravity of sin, it is customary to distinguish between mortal and venial sins (1849, 1853, 1854)."
(Catechism of the Catholic Church, Glossary, S)

² The idea of comparing critters based on fractional or logarithmic differences comes from Isaac Asimov's essay, "That's About the Size of It" in:

• "View From a Height"
  Isaac Asimov (1963)

³ More about Earth's equatorial climate and big dinosaurs during the Late Triassic:

• "Extreme ecosystem instability suppressed tropical dinosaur dominance for 30 million years"
  Jessica H. Whiteside, Sofie Lindström, Randall B. Irmis, Ian J. Glasspool, Morgan F. Schaller, Maria Dunlavey, Sterling J. Nesbitti, Nathan D. Smith, Alan H. Turnerk (May 15, 2015)
• "Climatically driven biogeographic provinces of Late Triassic tropical Pangea"
  Jessica H. Whiteside, Danielle S. Grogan, Paul E. Olsen, Dennis V. Kent; (March 3, 2011)