Tag Archives: nature

Leafhopper Feeding a Gecko

Some of this stuff is just fun. The leafhopper feeds on the sap of the tree. And the Gecko will stop by and wait to be fed. The narrator explains that scientists have not determined why this happens, perhaps the Gecko keeps aware predators? That seems somewhat flimsy as a guess to me but what do I know. The narrator does say that the sweet honeydew is what remains from the sap once the leafhopper has extracted the protein.

Related: Macavity’s a Mystery Cat – Swimming Ants

Parasite Rex

Parasite Rex is a great book by Carl Zimmer (one of the bloggers listed in the Curious Cat directory of science blogs). This is the first book read as part of my specific plan to read more about bacteria, cells, virus, genes and the like.

One of the most enjoyable aspects of writing this blog is that I have focused much more on cool things I read. And over time the amazing things I posted about related to these topics made me realize I should put some focused effort to reading more on these topics. Some of the posts that sparked that idea: Tracking the Ecosystem Within Us – Inner Life of a Cell: Full Version – Where Bacteria Get Their Genes, People Have More Bacterial Cells than Human Cells, Biological Molecular Motors – Energy Efficiency of Digestion – Old Viruses Resurrected Through DNA – Midichloria mitochondrii – Microbes – Using Bacteria to Carry Nanoparticles Into Cells – How Bacteria Nearly Destroyed All Life – New Understanding of Human DNA – Soil Could Shed Light on Antibiotic Resistance – Symbiotic relationship between ants and bacteria

Parasite Rex was a great place to start. Carl Zimmer is a great writer, and the details on how many parasites there are and how interconnected those parasites are to living systems and how that has affected, and is affecting, us is amazing. And the next book I am reading is also fantastic: Good Germs, Bad Germs. Here is one small example from Parasite Rex, page 196-7:

A person who dies of sickle cell anemia is less likely to pass on the defective gene, and that means the disease should be exceedingly rare. But it’s not – one in four hundred American blacks has sickle sell anemia, and one in ten carries a single copy of the defective gene. The only reason the gene stays in such high circulation is that is also happens to be a defense against malaria.

Malaria is a parasite. One of the amazing things with repeated examples in the book were parasites that seemed to have extremely complicated life cycles (that don’t seem like a great strategy to prosper but obviously work). Where they grow in one life form (an insect or mammal or whatever) but must leave that life form for some other specific life form for the next stage in life (they cannot have descendants without doing so…). Seems like a crazy way to evolve but it happens over and over again.
Continue reading →

Understanding the Evolution of Human Beings by Country

graphic showing countries understanding of evolution I recently wrote about evolution and scientific literacy. The graph on the left shows the percentage of the population that understands evolution is a core scientific principle. The graph based on data from 2005 for 34 countries.

Blue indicates those that know that “human beings, as we know them, developed from earlier species of animals.”
Yellow are those that are unsure
Red are those that don’t know that it is true

Evolution Less Accepted in U.S. Than Other Western Countries, Study Finds, from National Geographic News:

A study of several such surveys taken since 1985 has found that the United States ranks next to last in acceptance of evolution theory among nations polled. Researchers point out that the number of Americans who are uncertain about the theory’s validity has increased over the past 20 years.

The United States is is second to last place in this question of scientific literacy with only 40% of the population knowing the truth. The USA was between Cyprus and Turkey in this measure of understanding of scientific knowledge. The most knowledgeable countries have about twice the rate of knowledgeable respondents (with nearly 80% knowing).

Related: Scientific Illiteracy by Country (the USA managed to stay in the top 10 for overall scientific literacy rate of 8th graders in 2003) – Understanding Evolution (University of California at Berkeley) – Scientifically Illiteracy – Retroviruses – DNA Repair Army – Massive Project Will Reveal How Humans Continue to Evolve – Gene Study Finds Cannibal Pattern – Nigersaurus – Rare Chinese Mountain Cat

People Have More Bacterial Cells than Human Cells

Humans Carry More Bacterial Cells than Human Ones

All the bacteria living inside you would fill a half-gallon jug; there are 10 times more bacterial cells in your body than human cells
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The infestation begins at birth: Babies ingest mouthfuls of bacteria during birthing and pick up plenty more from their mother’s skin and milk—during breast-feeding, the mammary glands become colonized with bacteria. “Our interaction with our mother is the biggest burst of microbes that we get,”
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there are estimated to be more than 500 species living at any one time in an adult intestine, the majority belong to two phyla, the Firmicutes (which include Streptococcus, Clostridium and Staphylococcus), and the Bacteroidetes (which include Flavobacterium).
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probiotics – dietary supplements containing potentially beneficial microbes – have been shown to boost immunity. Not only do gut bacteria “help protect against other disease-causing bacteria that might come from your food and water,” Huffnagle says, “they truly represent another arm of the immune system.”
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But the bacterial body has made another contribution to our humanity – genes. Soon after the Human Genome Project published its preliminary results in 2001, a group of scientists announced that a handful of human genes – the consensus today is around 40 – appear to be bacterial in origin.

How cool is science? Very, I think 🙂

Related: Tracking the Ecosystem Within Us – Beneficial Bacteria – Energy Efficiency of Digestion – Large Number of Bacteria on our Skin – Where Bacteria Get Their Genes – Amazing Science: Retroviruses

Monarch Butterfly Migration

Monarch Butterfly

Helping track the monarch butterfly migration is a very cool interactive learning projects for students. The Monarch Butterfly Journey North site includes a great wealth of resource with real time reports and answers to science questions.:

A massive migration across Oklahoma, Arkansas, and Kansas this week resulted in the most spectacular sightings of the season. Most miraculous was the mile of clustering monarchs discovered on Sunday in a sunflower field in Kansas. Just think…It’s the first week of October and migrating monarchs are still being spotted across the north.

From the Monarchs in the Classroom website:

Unlike most other insects in temperate climates, monarch butterflies cannot survive a long cold winter. Every fall, North American monarchs fly south to spend the winter at roosting sites. Monarchs are the only butterflies to make such a long, two-way migration, flying up to 3000 miles in the fall to reach their winter destination. Amazingly, they fly in masses to the same winter roosts, often to the exact same trees. Their migration is more the type we expect from birds or whales than insects. However, unlike birds and whales, individuals only make the round-trip once. It is their children’s grandchildren that return south the following fall.

Monarch Travels (2006 post)

To test their ability to reorient themselves, Dr. Taylor has moved butterflies from Kansas to Washington, D.C. If he releases them right away, he said, they take off due south, as they would have where they were. But if he keeps them for a few days in mesh cages so they can see the sun rise and set, “they reset their compass heading,” he said. “The question is: How?”

Related: – Evolution at Work with the Blue Moon Butterfly – Two Butterfly Species Evolved Into Third – Diversity of insect circadian clocks – the story of the Monarch butterfly

Tracking the Ecosystem Within Us

Gut Check: Tracking the Ecosystem Within Us

For more than 100 years, scientists have known that humans carry a rich ecosystem within their intestines. An astonishing number and variety of microbes, including as many as 400 species of bacteria, help humans digest food, mitigate disease, regulate fat storage, and even promote the formation of blood vessels. By applying sophisticated genetic analysis to samples of a year’s worth baby poop, Howard Hughes Medical Institute researchers have now developed a detailed picture of how these bacteria come and go in the intestinal tract during a child’s first year of life.
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Before birth, the human intestinal tract is sterile, but babies immediately begin to acquire the microbial denizens of the gut from their environment — the birth canal, mothers’ breast, and even the touch of a sibling or parent. Within days, a thriving microbial community is established and by adulthood, the human body typically has as many as ten times more microbial cells than human cells.
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The results, said Palmer, were striking: the group found that the intestinal microbial communities varied widely from baby to baby – both in terms of which microbes were present and in how that composition changed over time. That finding, she said, is important because it helps broaden the definition of healthy microbial colonization in a baby.

Another intriguing observation, Palmer noted, was a tendency for sudden shifts in the composition of the infants’ intestinal microbial communities over time as different species of bacteria ebbed and flowed.

I find this area and this study fascinating. I’m not exactly sure why this study and the incredibly significant positive bacteria for human life news doesn’t get more notice. Oh well I guess there are not cool pictures of robots or scary stories of potential threats to those reading which makes the news less interesting to some. Still I find this stuff amazing: Energy Efficiency of Digestion – Beneficial Bacteria – Skin Bacteria – Hacking Your Body’s Bacteria for Better Health – Where Bacteria Get Their Genes

Altered Oceans: the Crisis at Sea

Extensive LA Times series on Altered Oceans: the Crisis at Sea [sigh, once agin pointy haired bosses broke a links, so they were removed – when will we have web sites run by people that understand basic usability?] by Kenneth R. Weiss and Usha Lee McFarling. Excellent.

Part 1 (of 5): A Primeval Tide of Toxins “Runoff from modern life is feeding an explosion of primitive organisms. This ‘rise of slime,’ as one scientist calls it, is killing larger species and sickening people”

Part 4: Plague of Plastic Chokes the Seas:

Their flight paths from Midway often take them over what is perhaps the world’s largest dump: a slowly rotating mass of trash-laden water about twice the size of Texas.

This is known as the Eastern Garbage Patch, part of a system of currents called the North Pacific subtropical gyre. Located halfway between San Francisco and Hawaii, the garbage patch is an area of slack winds and sluggish currents where flotsam collects from around the Pacific
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Nearly 90% of floating marine litter is plastic — supple, durable materials such as polyethylene and polypropylene, Styrofoam, nylon and saran.

About four-fifths of marine trash comes from land, swept by wind or washed by rain off highways and city streets, down streams and rivers, and out to sea.

I have been unable to find a decent photo of this garbage patch – please post a comment if you know of one.

Incredible Insects

Incredible Insects facts from the Smithsonian, including:

  • Fastest Flying Insect: Dragonflies are known to travel at the speed of 35 miles an hour.
  • The Longest-lived Insect: The queen of termites, known to live for 50 years. Some scientists believe that they live for 100 years.
  • The Loudest Insect: One species of cicadas can be heard for a quarter of a mile.

More Incredible Insect Facts and Information