"Bones" as Ballast in Bacteria (!)

[wet]

One of the premises of the Aquatic Ape scenario is that many coastal archaic human (H. erectus) fossil bones are unusually dense and robust 9compared to both modern humans and apes), and may have acted as ballast for slow dive foraging similar to walruses and manatees (and many other extinct divers). Sometimes the dense bones function both as ballast and armor (turtles, dugongs), and sometimes as mineral stores that can later be redistributed via osteoblasts/osteoclasts & bloodstream for later use.
So with that in mind, I found this interesting. [Cyanobacteria are blue-green algae, they don't need to breath-hold, since they are photosynthetic.]
===

Bony Bacteria - Science News
Bony bacteria: New species builds hard structures inside cells
Rachel Ehrenberg 26.4.12

Scientists have discovered a cyanobacterium that makes tiny calcified
structures inside its cells.
Related microbes calcify on the outside.

Karim Benzerara & Stephan Borensztajn (Science) have discovered skeletons
in the cyanobacterial closet.
A never-before-seen species of cyanobacterium loads its cells with little
bone-like lumps that may act as ballast, helping to anchor the beastie in
its home waters of a Mexican lake.
The discovery is the first report of such a microbe creating calcified
structures inside its cells, rather than externally.
Scientists aren¹t sure what to make of the discovery.
Related cyanobacteria play a major role in the planet's geochemical
cycles.
Robert Riding wrote a comment in Science:
"It's interesting and opens up possibilities we hadn't thought about
before."
Because the microbe is the first of its kind, and so far, has been found
in only one place, "it's difficult to know where it will lead."
Geobiologist Karim Benzerara cs were investigating Lake Alchichica's
stromatolites, knobby pillars of sediment & microbes that can form in
shallow waters.

[Unrelated topic: "brinicles" are salt brine 'icecicles' or stalactites that form under stagnant ice floes, sometimes connected to the shallow antarctic ocean floor] ​

They cultivated slimy films of the microbes in a lab aquarium.
Looking at the slime under a microscope, they saw that some cells looked
like they were filled with little pearl-like granules.
The granules are an unusual mixture of calcium, strontium, barium,
magnesium & carbonate.
Because the ratios of these ingredients aren't the same in the granules as
in the surrounding water, the researchers suspect that the cyanobacteria
have some control over formation of the lumps, and are actively
transporting some of the ingredients into their cells.
The lumps (occupy c 6 % of a cell) change the microbe's density,
increasing it by 12 %.
This might help the microbes move from the water column to the surface of
an underwater rock or stromatolite, the researchers speculate.

Even more intriguing is what the microbes might have been doing during
Earth's history, says geo-microbiologist Clara Chan.
The new species is a type of cyanobacteria (blue-green algae) known for
making Earth's atmosphere more breathable:
"Cyanobacteria are really the movers & shakers of the Earth.
They were a major source of oxygen."
Long before land plants were around, ocean-dwelling cyanobacteria were
oxygenating the atmosphere.
And when ocean chemistry favored the precipitation of minerals out of
solution, calcified crystals formed on the outside of the cells of many of
these cyanobacteria as a byproduct of photosynthesis. There's good
evidence of these calcified structures in the fossil record from c 1200 to
100 Ma.
Beyond 1200 ma, the record is much spottier, even though cyanobacteria are
thought to have existed for the past 2700 ma.
The new species Candidatus Gloeomargarita lithophora may help explain the
gaps in the record.
A genetic analysis by Benzerara cs suggests that it is part of an ancient
lineage of cyanobacteria, the Gloeobacterales.
If back in the day, related species created internal granules, rather than
external shell-like structures, perhaps the granules wouldn't show up in
the fossil record.
The researchers don't yet know whether the granules dissolve or leave a
trace after the cyanobacterium dies.

 

[efattah]

This is interesting, because it appears that my bones have gotten denser and denser and denser after 14 years of freediving. I never understood why.

 

[shrugs]

Would denser bones mean stronger bones? Just a thought.


Sent from my iPhone using Tapatalk

 

[wet]

This is interesting, because it appears that my bones have gotten denser and denser and denser after 14 years of freediving. I never understood why.

It depends on many factors (genetics, diet, general exercize) but I'd expect that over a long period, habitual consistent full-lung diving (with not-too-heavy weight belt) would produce some incremental compact bone increase.

Empty-lung diving would have much less effect, as would over-weighted diving.

Dugongs have both large long lungs and dense bones, dolphins have relatively small lungs and lower density bones (their ancient ancestors had dugong-like anatomy, but refinements in oxygen storage capacity in muscle allowed dispensing with the dense bones and large lungs.)

 

[wet]

Would denser bones mean stronger bones? Just a thought.

No. Denser = ballast = compact (stone-like) bone with reduced sponge-like cancellous (which allows bending strength) internal bone. Dugongs lack internal spongey bone, so their bones are very brittle, hard but not strong. Dolphin bones are porous & oily, are strong but not very hard. (Octupi have strong but not hard tentacles.)

stone vs air storage in lungs

 

[wet]

OT to diving, but NY times story on major extinction 252ma killed massive marine life. Possibly linked to bluegreen algae "bone" formation:

http://www.nytimes.com/2012/05/01/s...extinction-shed-light-on-the-great-dying.html

marine "animals died from a lack of dissolved oxygen in the water, an excess of carbon dioxide, a reduced ability to make shells from calcium carbonate, altered ocean acidity and higher water temperatures"

"So what happened 252 million years ago to cause those physiological stresses in marine animals? Additional clues from carbon, calcium and nitrogen isotopes of the period, as well as from organic geochemistry, suggest a “perturbation of the global carbon cycle,” the scientists’ second paper concluded — a huge infusion of carbon into the atmosphere and the ocean.

But neither an asteroid strike nor an upwelling of oxygen-deprived deep-ocean water would explain the selective pattern of death.

[That's FALSE in my opinion; giant Asteroid hit earth which caused mass vulcanism at antipode activating changed atmosphere (high CO2 from volcanoes), in both 250ma Permian/Siberian traps and 65ma KT/Dekkan traps, only difference was that Permian asteroid impacted deep-ocean while KT asteroid impacted mostly dry land. DD]


Instead, the scientists suspect that the answer lies in the biggest volcanic event of the past 500 million years — the eruptions that formed the Siberian Traps, the stairlike hilly region in northern Russia. The eruptions sent catastrophic amounts of carbon gas into the atmosphere and, ultimately, the oceans; that led to long-term ocean acidification, ocean warming and vast areas of oxygen-poor ocean water.

 

[wet]

Bone density in marine "dinosaurs"

Osteo-histology of Mesozoic marine tetrapods
* implications for longevity, growth strategies and growth rates
Johan Gren 2010
Bachelor Thesis, Dept Earth & Ecosystem Sciences, Lund Univ
...

This study deals with the histology of fossilized bone from 3 groups of
tetrapods, secondarily adapted to marine life, but with different bone
micro-structures:
1) Ichthyosaur bone is light (extensive vascularization, ie, osteoporosis),:
increased manoeuvrability in open waters cf most extant whales & dolphins?
2) Plesiosaur bone is very dense & heavy (POS): for ballasting in a
near-shore shallow marine environment cf modern Sirenia?
3) Sea turtles display a lamellar moderately-vascularized bone pattern cf
most recent turtles & crocodiles = rel.slower growth rates than in
ichthyosaurs?

The maturity of the animals at hand has also been investigated:
1) the ichthyosaur is a young adult or late juvenile,
2) the plesiosaur is immature,
3) the sea turtle is adult, displaying at least 17 annual growth rings.

...

The bone of vertebrates is always more or less vascularized.
The vascular canals commonly contain lipids, and an increased presence of
such bio-molecules makes the skeleton lighter.
In marine animals, this bone modification has effects on swimming speeds,
manoeuvrability & lifestyle.
The 3 animal groups studied have all rather different levels of
vascularization & histological organizations.

1) The ichthyosaur bone structure is very similar to the leatherback turtle
Dermochelys coriacea, comparable to what is commonly seen in whales &
dolphins (adapted for sustained swimming, often over large distances)
As the ichthyosaurs were active predators, the increase in speed &
manoeuvrability that a lighter skeleton provides would have aided in the
pursuit of prey.

2) As for the plesiosaur, sustained pursuit of prey would be harder. Massare
(1988) refers to plesiosaurs as "ambush predators", capable of quick bursts
of speed to capture a passing prey, but not capable of high sustained
cruising speeds.
Wiffen cs (1995) suggested changes from POS to an osteoporotic-like state
during ontogeny:
- Juvenile plesiosaurs preferred more shallow water environments cf Sirenia?
Fed upon fixed organisms or non-elusive prey?
- Adults lived in more open marine environments?
The plesiosaurian osteo-histological pattern, if an ontogenetic change in
bone re-organization indeed did occur, differs from that of any known extant
animal group.

3) The observed histological features of the sea-turtle are consistent with
Peabody's & Rhodin's descriptions of the general bone micro-structures in
modern chelonians (excluding D.coriacea).
As their main prey items are plankton, sea grass & algae, swimming-speed is
of less importance for modern sea turtles when foraging.
The chelonian bone is more cancellous than that of the plesiosaur, making it
easier for it to move across larger distances, as less amounts of energy are
needed with a lighter skeleton.

Comparisons can also be made between these 3 marine tetrapod groups & the
dinosaurs.
A lot of research has been conducted on the osteo-histology of other
Mesozoic reptiles, eg, terrestrial dinosaurs, to help formulating theories
on
- dinosaur growth rates,
- thermoregulation,
- ontogenetic patterns &
- insular dwarfism.
Studies on dinosaurian growth show that this group did not grow as other
reptiles.
Most other reptiles
- deposit woven-fibred bone only during their first few growth cycles &
- then start producing lamellar bone.
Dinosaurs never underwent this change in bone structure, but continued to
produce woven-fibred bone all the way though adulthood.
Parallels can thus be drawn to ichthyosaur bone, which also lacks lamellar
bone typical of many reptiles incl.chelonians.
The deposition of woven-fibred bone throughout ontogeny is somewhat similar
to most extant birds & mammals, to suggest a steep sigmoidal growth curve,
reaching a plateau rather early in adulthood (in most reptiles, the growth
curve is more linear).

Sea turtles display lamellar slow-growing bone, present in many recent
reptiles.
This bone organization indicates a continuous bone growth throughout
adulthood, and the LAGs present in the sample at hand indicate the femur
originates from an adult animal.
The vascularized limb bones presumably provided manoeuvrability in open
waters, although sea turtles lack the osteoporotic adaptations found in e.g.
ichthyosaurs.

The ichthyosaur skeleton is made up by osteoporotic bone, presumably as an
adaptation for increased speed & manoeuvrability.
The bone is primarily of woven-fibred type, indicating a fast growth to
adult size.

In the plesiosaur bone, a POS pattern is observed.
This pattern increased the skeletal weight due to increased density, and was
probably used as ballast in a shallow water environment.

 

[wet]

http://www.nytimes.com/2013/06/11/health/new-rapid-malaria-test-uses-magnets-and-a-laser.html?_r=0

A student-professor team at Case Western Reserve University has invented a hand-held malaria detector that works on an unusual principle: Malaria parasites are stuffed with iron [~ "bone" store], so their innards can be magnetized.

The team, which has incorporated itself as the Disease Diagnostic Group, is seeking investors to pay for field tests to prove that its device works as well on the African front lines as it does in a Cleveland lab. Its pitch is that its battery-powered box, which costs $250 to make, can undercut the price of current chemical-based rapid test kits by at least 50 cents per test and pay for itself quickly. The company claims its test is far more accurate than the kits at detecting low-level infections.

It has long been known that malaria parasites eat the hemoglobin in red blood cells but cannot digest its iron nor excrete it. Each parasite has a holding tank called a food vacuole filled with iron-rich crystallized hemozoin. [equivalent to mineralized bones in mammals, which then evolved to function as ballast, structure, etc.]

=

excellent gadget, waiting for the cell phone app version...