Category Archive 'Biology'

12 Apr 2018

No Wonder There Are So Many Democrats!


The BBC reports that the human part of humanity is outnumbered.

More than half of your body is not human, say scientists.

Human cells make up only 43% of the body’s total cell count. The rest are microscopic colonists.

Understanding this hidden half of ourselves – our microbiome – is rapidly transforming understanding of diseases from allergy to Parkinson’s.

The field is even asking questions of what it means to be “human” and is leading to new innovative treatments as a result.

“They are essential to your health,” says Prof Ruth Ley, the director of the department of microbiome science at the Max Planck Institute, “your body isn’t just you”.

No matter how well you wash, nearly every nook and cranny of your body is covered in microscopic creatures.

This includes bacteria, viruses, fungi and archaea (organisms originally misclassified as bacteria). The greatest concentration of this microscopic life is in the dark murky depths of our oxygen-deprived bowels.

Prof Rob Knight, from University of California San Diego, told the BBC: “You’re more microbe than you are human.”

Originally it was thought our cells were outnumbered 10 to one.

“That’s been refined much closer to one-to-one, so the current estimate is you’re about 43% human if you’re counting up all the cells,” he says.

But genetically we’re even more outgunned.

The human genome – the full set of genetic instructions for a human being – is made up of 20,000 instructions called genes.

But add all the genes in our microbiome together and the figure comes out between two and 20 million microbial genes.


03 Jan 2018

Human Eye Colors Explained

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Paul Van Slembrouck:

Did you think that blue eyes are blue because they contain blue pigmented cells? Did you think that green eyes are green for the same reason?

Think again.

That colorful circle around your pupil is the iris. The iris is made up of two layers of cells: the front layer is known as the stroma, and the back layer is known as the epithelium.

The epithelium is a layer with a thickness of two cells and containing dark black-brown pigments. The little specks and strings of black you see in the iris? — that’s the epithelium.

The stroma is made up of colorless collagen fibers. The stroma only occasionally contains brown melanin pigmentation. Sometimes the stroma is totally clear, containing no melanin. …

To everyone curious about Elizabeth Taylor’s mythical violet eyes, the short answer is that — as far as I know — she had grey-blue eyes that could be coaxed into appearing violet with the appropriate lighting or makeup and attire.


07 Jul 2015

“Unequivocal Evidence” of Extraterrestrial Life on Comet

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Sky News:

Evidence of alien life is “unequivocal” on the comet carrying the Philae probe through space, two leading astronomers have said.

The experts say the most likely explanation for certain features of the 67P/Churyumov-Gerasimenko comet, such as its organic-rich black crust, is the presence of living organisms beneath an icy surface.

Rosetta, the European spacecraft orbiting the comet, is also said to have picked up strange “clusters” of organic material that resemble viral particles. …

“[D]ata coming from the comet seems to unequivocally, in my opinion, point to micro-organisms being involved in the formation of the icy structures, the preponderance of aromatic hydrocarbons, and the very dark surface.

“These are not easily explained in terms of pre-biotic chemistry.

“The dark material is being constantly replenished as it is boiled off by heat from the Sun. Something must be doing that at a fairly prolific rate.”

19 Nov 2013

Gut Bacteria Å°ber Alles

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Not only do gut bacteria regulate our metabolism, NPR tells us, some scientists now think that the same bacteria may influence moods, emotions, and may even behind some mental disorders like bipolarity and autism.

31 Jul 2013

Gone, But Not Forgotten

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Isabella Kirkland, Gone

Still weeping into your handkerchief over missing Carolina parakeets, Heath Hens, and Passenger pigeons? Studio 360 tells us that modern science is working on bringing extinct species back.

Bringing extinct animals back has usually been left to the world of science fiction. But a group of biologists is attempting it in the real world. The organization Revive & Restore, a project of the Long Now Foundation, held a day-long TEDx conference on de-extinction a few months ago at the National Geographic Society. This is not quack science; some of the research involves Harvard University, UC Santa Cruz, and Wake Forest University, among other institutions.

Painter Isabella Kirkland, who is also a research associate at the California Academy of Sciences, opened the event with an image of her painting Gone. It looks like a Dutch master’s oil painting, depicting 63 extinct New World species arrayed on a table elegantly: the Carolina parakeet, the golden toad, and in the central place of honor, Martha, the last passenger pigeon, who died in 1914.

The passenger pigeon is the preoccupation of Revive & Restore’s Ben Novak, a genetic biologist. “It’s my job to bring the bird back to life.” Novak began thinking about resurrecting animals in junior high school, when he did a science fair project on the dodo bird. “It’s the icon of extinction — ‘dead as a dodo,’ as they say — and I learned that the dodo is actually a giant extinct pigeon. It gave me the pigeon bug.” The techniques are complicated and untried, but de-extinction is simple in concept: take DNA from a dead sample in a natural history museum somewhere, and plant it in the egg of a living relative — in this case, the band-tailed pigeon. If it works, the living bird will hatch an egg out of which will come the clone of a long-dead bird.

I would vote for bringing back Pleistocene megafauna, which would provide some excellent hunting trophies. Bringing back the Passenger pigeon seems like a bad idea to me. We already have plenty of Mourning Doves which fill the Passenger pigeon’s ecological niche pretty satisfactorily. Besides, it seems possible, speaking historically, that Passenger pigeons (and Carolina parakeets) were, at least in part, intentionally eradicated because they were voracious flock feeders on crops.

Hat tip to Daniela Imre.

15 Jul 2013


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Garfunkel & Oates perform a comedy song highlighting the differences in female perspective that can occur in only two short years between the ages of 29 and 31. I thought it was pretty funny.

15 Jul 2013

Scientists Identify Feminine Odors Which Make Sperm Wag Their Tails



Sperm are the cheetahs of the microscopic world: Made of little more than molecular muscle and batteries, tipped with a payload of genetic information, they are optimized for speed. But to orient themselves before their epic, seven-inch sprint (it’s more impressive if you’re less than one three-thousandth that size), they first need to sniff out the location of the egg—and, it turns out, the analogy to the sense of smell may be particularly apt.

We’ve known for years that something in the secretions of the female reproductive tract attracts sperm: Any biologist with easy access to said secretions, semen, and a Petri dish can see that. Making the connection between the soup of candidate molecules floating around in there and the sperm’s journey to the egg is a bit trickier, but lately, scientists have discovered that sperm are equipped with odor receptors usually found in the nose. In a study published last week, researchers identified two odor molecules present in the fluids near the egg and in the vagina in general. And those chemicals trigger some of the receptors in sperm, causing a chemical reaction of the sort that gets sperm cells’ motors humming.

The researchers first identified 40 scent molecules present in the fluids of 17 women—molecules that, if you were to sniff them (i.e., let them activate the odor receptors in your nose), would range in smell from vanilla-like to bell peppery to sulfurish. They then dabbed them one by one on lab-grown cells engineered to carry the receptors. They found that two (a urine-y scent and a caramel-like one) caused the cells to release calcium, which makes sperm whip their tails. They then applied the molecules to live sperm, and found that while the intact fluids got the sperm wiggling much more reliably, the odors got a large fraction of them swimming as well. The researchers say that this is a sign that the molecules may be involved in attracting sperm egg-wards.

Via Vanderleun.

29 Feb 2012

Two New Blood Types Added

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Science Daily reports that the count of blood group proteins has been increased for the first time in more than a decade by two more, raising the count from 30 to 32.

You probably know your blood type: A, B, AB or O. You may even know if you’re Rhesus positive or negative. But how about the Langereis blood type? Or the Junior blood type? Positive or negative? Most people have never even heard of these.

Yet this knowledge could be “a matter of life and death,” says University of Vermont biologist Bryan Ballif.

While blood transfusion problems due to Langereis and Junior blood types are rare worldwide, several ethnic populations are at risk, Ballif notes. “More than 50,000 Japanese are thought to be Junior negative and may encounter blood transfusion problems or mother-fetus incompatibility,” he writes.

But the molecular basis of these two blood types has remained a mystery — until now.

In the February issue of Nature Genetics, Ballif and his colleagues report on their discovery of two proteins on red blood cells responsible for these lesser-known blood types.

Ballif identified the two molecules as specialized transport proteins named ABCB6 and ABCG2.

“Only 30 proteins have previously been identified as responsible for a basic blood type,” Ballif notes, “but the count now reaches 32.”

The last new blood group proteins to be discovered were nearly a decade ago, Ballif says, “so it’s pretty remarkable to have two identified this year.”

26 Feb 2008

Encyclopedia of Life


The New York Times reports that a group of scientists is starting an on-line biological encyclopedia of species, to be developed and completed over time by Wikipedia-style volunteer contributors.

Imagine the Book of All Species: a single volume made up of one-page descriptions of every species known to science. On one page is the blue-footed booby. On another, the Douglas fir. Another, the oyster mushroom. If you owned the Book of All Species, you would need quite a bookshelf to hold it. Just to cover the 1.8 million known species, the book would have to be more than 300 feet long. And you’d have to be ready to expand the bookshelf strikingly, because scientists estimate there are 10 times more species waiting to be discovered.

An Online Catalog of Biodiversity It sounds surreal, and yet scientists are writing the Book of All Species. Or to be more precise, they are building a Web site called the Encyclopedia of Life ( On Thursday its authors, an international team of scientists, will introduce the first 30,000 pages, and within a decade, they predict, they will have the other 1.77 million.

While many of those pages may be sparse at first, the authors hope that the world’s scientific community will pool all of its knowledge on the pages.

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