Monday, August 17, 2015
There were many jewels in Hawai`i’s natural treasure chest, and today, the rarest of these are the land snails.
The Hawaiian archipelago's natural legacy was a splendid array—forest birds in all the colors of the rainbow, flashing reef fishes found nowhere else on the planet, and the stunning silver and crimson, gold and purple hues of the flowers.
In that array, the land snails may not stand out, although there were once hundreds of species. Today, they are recognized for their singular rarity.
(Image: One of the last remaining amastrid land snail species on O'ahu, Laminella sanguinea, in the Waianae Mountains. Credit: Kenneth A. Hayes, University of Hawai’i)
There were once 325 species of Amastridae that were unique to these islands. Today, only 15 can be found.. An extinction rate of more than 95 percent.
This tally was published in the journal "Conservation Biology" by researchers from the University of Hawai`i’s Pacific Biosciences Research Center, Bishop Museum, and national and international teams. It is entitled “Extinction in a hyperdiverse endemic Hawaiian land snail family and implications for the underestimation of invertebrate extinction."
Of the 325, only 33 are officially listed as extinct on the International Union for Conservation of Nature (IUCN) Red List. But that’s because the paperwork can’t keep up with the rate of extinction.
“Of the 325 Amastridae species, 43 were originally described as fossil or subfossil and were assumed to be extinct. Of the remaining 282, we evaluated 88 as extinct and 15 as extant and determined that 179 species had insufficient evidence of extinction (though most are probably extinct),” the authors wrote.
When scientists write about extinction crises, they’re often mostly talking about vertebrates—the birds and mammals, fishes and reptiles. But to miss the invertebrates is to miss a lot.
“Invertebrates have received much less attention despite their constituting as much as 99% of animal species richness,” the authors write.
To assess the status of Amastridae, the researchers studied collections in the Bishop Museum and then went into the field, looking t 481 potential snail habitats throughout the Islands.
“At many sites, we collected leaf litter and soil, which we searched under a microscope for especially small snails. This is the most comprehensive and temporally focused land snail survey effort ever undertaken in the Islands,” they wrote.
They found just the 15. If you’re interested in the list, here it is.
“These 15 species were recorded during recent field work, including our field work specifically targeting amastrids in the Waianae Mountains of Oahu (Amastra cylindrica , Amastra micans , Amastra spirizona , Laminella sanguinea , Leptachatina cerealis , Leptachatina crystallina , Leptachatina gracilis , Leptachatina gummea , Leptachatina persubtilis, Leptachatina popouwelensis ), on Kauai (Leptachatina cuneata , Leptachatina cylindrata), on Maui (Laminella aspera , Leptachatina nitida), and on the island of Hawaii ( Leptachatina lepida),"
What could have caused this extinction catastrophe? Not just one cause. The authors make a list.
Humans (early Hawaiians) arrived and launched habitat destruction. They also brought Polynesian rats, which ate some snails but weren’t as big an issue as later introductions.
Then came Europeans with the next big wave of extinctions, caused by pigs, goats, and other species. Polynesian rats and black rats arrived and were big predators of snails.
Massive land clearing for ranching and plantation agriculture added to the toll, along with introduced predatory snails, and ants, and competition from introduced non-predatory snails.
Some of the same authors also participated in another paper that looked at extinction of poorly known life forms globally. Again, it suggests the extinction rate in modern times is far higher than we’ve believed.
Among its points: “Mammals and birds provide the most robust data, because the status of almost all has been assessed. Invertebrates constitute over 99% of species diversity, but the status of only a tiny fraction has been assessed, thereby dramatically underestimating overall levels of extinction. Using data on terrestrial invertebrates, this study estimates that we may already have lost 7% of the species on Earth and that the biodiversity crisis is real.”
© Jan TenBruggencate 2015
Tuesday, August 11, 2015
When it comes to food, we’re touchy.
We’re prone to believe all kinds of strange stuff--some things that just aren’t true at all, and a lot of things that are only marginally true, and a fair amount of things that are just weird.
We’re likely to be convinced that certain foods are literal life-savers.
That, for example, you’ll be eternally protected if you eat enough blueberries, or noni, or whole grain bread, or tree nuts, or seaweeds, or salba seed, or honey, or bee pollen, or coconut oil, or cruciferous vegetables, or chia seeds, or salmon, or chicken rather than beef, or fish rather than pork—this list goes on forever.
Just Google ‘miracle foods.’
And we believe bad things about certain foods.
The tomato, today a key ingredient in salads and Italian cooking, 200 years ago in the United States was believed poisonous. Today, it is sometimes listed among the miracle foods. How things change.
The tomato is an American plant that was happily and safely eaten by Central Americans. But for strange reasons, some of them religious, it was deemed toxic in North America a couple of hundred years ago. It wasn’t until the tomato had been exported to Europe, turned into a key part of that cuisine, and brought back to America by immigrants, that tomatoes were trusted again.
Folks used to believe eggplants would cause insanity.
And a lot of people today believe that meat is bad for you, despite this intriguing statistic: almost all of the longest-lived peoples in the world eat meat. The key: They seem to eat it infrequently and then sparingly.
Folks in Sardinia, Italy, where they eat a lot of milk and cheese, live on average a very long time—they are among the longest living group of people in the world. You’ve been told those dairy products are bad for you, right?
Oh, and you’ve been told alcohol is bad for you. Sardinians drink wine, too.
Noted Hawai`i physician nutritionist Dr. Terry Shintani recommends eating unprocessed foods. His diet suggestions include a lot of fresh stuff, mostly vegetarian, and a lot of it local. That is one interesting feature of the diets of almost all of the longest-living people—they eat stuff that comes from their immediate environment.
They eat the milk and meat of animals they knew, vegetables from gardens they tended or their friends did.
Some folks will argue that you’re likely to get much better nutrition and be much healthier if you eat an organic diet. Is there any actual support for that position? Not according to a paper in the Annals of Internal Medicine.
“The published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods,” the study says.
So what is reasonable advice? Some seems to come from the U.S. Department of Health and Human Services’ Dietary Guidelines for Americans 2010. It says stay active, eat fewer calories and be mindful of what you’re eating.
“A healthy eating pattern limits intake of sodium, solid fats, added sugars, and refined grains and emphasizes nutrient-dense foods and beverages—vegetables, fruits, whole grains, fat-free or low-fat milk and milk products, seafood, lean meats and poultry, eggs, beans and peas, and nuts and seeds,” it says.
Not as interesting, perhaps, as blueberries and chia seeds on kale leaves, but there you go.
Looking at another standard, there seem to be three hallmarks of virtually every one of the most long-living communities in the world: They are active lifelong, and they don’t eat a lot, and they eat local produce.
Some of them drink alcohol, some not. Almost all eat meat and dairy products, although almost all eat meat only sparingly. A lot eat a lot of fresh fruit, nuts and vegetables.
That suggests this recipe for a long, healthy life. Finish your salad, push the main course away after only a bite or two, and then get up take a long walk.
© Jan TenBruggencate 2015
Monday, August 10, 2015
On Earth, researchers use fine differences in light and color to identify specific plant species in aerial photos, and even to distinguish diseased or stressed plants from healthy ones.
What if we could use a similar technique to identify life on other planets?
A team of University of Hawai`i scientists is proposing just that, and is targeting our nearest solar neighbor, Alpha Centauri—a binary star that is the third brightest star in the night sky. Its alternative names are Rigil Kent and Toliman.
The team is led by Dr. Svetlana Berdyugina, a visiting scientist at the University of Hawai`i’s NASA Astrobiology Institute, working with Hawai`i astronomers Jeff Kuhn, David Harrington and John Messersmith.
They propose to use existing telescopes that are outfitted with special polarization equipment, and to compare the light from space with the colors from Earth-based photosynthetic pigments. Reflected polarized light from a planet can be picked up even when a nearby star is overwhelmingly brighter.
In their research, the team “found that each biopigment has its own colored footprint in such polarized light,” they said in a pressrelease.
They seem to admit that chances seem slim. A single planet was discovered last year around one of Alpha Centauri’s three stars, Alpha Centauri B. But this planet is far closer to its sun than even baked Mercury is to our sun, and so hot that water probably can’t exist at the surface.
But using the powerful polarized photosynthetic signatures might identify other planets in what astronomers call the habitable zone—that area where liquid water can exist on the surface. The team believes that within the star cluster, Alpha Centauri B holds the best chance of having planets in the habitable zone.
© Jan TenBruggencate 2015
Sunday, August 2, 2015
Our environment flows through us, literally.
And that’s a powerful ally of the politics of fear.
An East Coast inventor recently re-energized his career with a press release and a speaking tour. Shiva Ayyadurai said he had shown that genetically engineered soy has formaldehyde in it. Gasp! Formaldehyde is embalming fluid.
Yes, and it’s also a naturally occurring chemical that is found everywhere, including at low levels in normal human beings. It’s naturally found in non-GM soy, and in carrots, tomatoes, fish, red meat, rainwater, and even air.
Ayyadurai announced he’d done a study of GM versus non-GM soy “in silico.” That means he did it in a computer, not in a biology lab, which is to say, there’s no actual hands-on study that supports his assertion that formaldehyde is any different depending on the source of your soy.
A recent statewide anti-GM speaking tour also left audiences fearful, due to a blend of tantalizing fact and bold fictions.
One of the speakers, Dr. Stephanie Seneff, a computer scientist, insisted that new pesticides are not properly tested, and that they’re dangerous. She failed to note that a new pesticide goes through as many as 300 studies before receiving approval for use. Here’s some of what the EPA studies.
Seneff is famous for predicting that 80 percent of boys and 50 percent of all children will be autistic by 2025, and that this is caused by the herbicide Roundup (or vaccines, or both.) She cites as evidence a graph of Roundup sales that she says matches a graph of autism increase since the 80s. Coincidence?
There are lots of coincidental correlations. A graph of CO2 increase in the atmosphere since then matches pretty well, too. A graph of the nominal gross domestic product of the People’s Republic of China is a real close match.
Roundup is certainly found in our environment, but Seneff, in the talk I attended, never mentioned one of the standards of the science of toxicology: That the dose makes the poison. And at normal levels of exposure, regulatory agencies have found there’s no threat.
We are part of our environment, and the environment flows through us.
At the low amounts found throughout our environment, formaldehyde is normal and harmless. In high amounts, it causes numerous problems. The focus on dose is one of the reasons that regulatory agencies set tolerance levels for food, drinking water and so forth—they set the levels for all kinds of compounds, below which there is little or no danger—even if at high levels there may be serious impacts.
Ralph Nader’s career was built on the book, “Unsafe At Any Speed.” One of the mantras of the fear industry is that if something is dangerous at high levels, it’s dangerous at all levels.
Formaldehyde? The National Cancer Institute says that high levels of it from industrial sources are a problem, but it adds that “Formaldehyde also occurs naturally in the environment. It is produced in small amounts by most living organisms as part of normal metabolic processes.”
The environment flows through us.
Even if you don’t ingest coffee, tea or chocolate, there is probably caffeine in your body. One source is the groundwater, where some of the caffeine ends up that other people ingest. The small amounts don’t harm you.
There is arsenic, which in some forms is a potent poison, in your system. You generally get it from food sources, but also tobacco. It generally washes out of your system fairly quickly. Here’s a World Health Organization fact sheet on arsenic.
The deadly poison cyanide is in food, too. Here’s a Centers for Disease Control paper on it.
Yes, there are normal human levels of cyanide, most of which comes from food.
We have potent poisons in our systems--many of them. At low enough levels, they’re not an issue.
One of the instructive compounds is water. Just enough, and you’re fine. Not enough, and you suffer from dehydration, which can kill you. Too much, and you suffer from water intoxication or hyperhydration, which can lead to nausea, confusion, seizures and ultimately death.
Back to Seneff and Ayyadurai. They’re both spinning the fear so hard that it’s difficult in their statements to find clear, balanced conclusions.
This is not to understate the dangers of exposure to dangerous levels of chemicals, but to say that we should judge our threats rationally.
We sit here with formaldehyde, arsenic and cyanide in our systems, same as our ancestors did. And that’s no more of a threat to us than it was to them.
© Jan TenBruggencate 2015