Tag Archives: evolution

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

Evolution is Fundamental to Science

Evolution is absolutely fundamental to scientific thinking. Any country, or part of a country (or those wishing to lead a country) that teaches evolution as though it is some alternative way of looking at the facts (that can be compared to creationism/intelligent design, as science, for example) is an embarrassment. Unfortunately the United States is home to far too much of this thinking – which explains why scientific literacy is so low. Luckily there are also plenty in the USA that understand science. The National Academy of Science has published, Science, Evolution, and Creationism, in which a

group of experts assembled by the National Academy of Sciences and the Institute of Medicine explain the fundamental methods of science, document the overwhelming evidence in support of biological evolution, and evaluate the alternative perspectives offered by advocates of various kinds of creationism, including “intelligent design.” The book explores the many fascinating inquiries being pursued that put the science of evolution to work in preventing and treating human disease, developing new agricultural products, and fostering industrial innovations. The book also presents the scientific and legal reasons for not teaching creationist ideas in public school science classes.

The scientific theory of evolution still has details that can be debated – which is what the scientists should and will do (seeking out evidence to support such details). The idea that people today can question evolution is beyond amazing to me. It is much easier to understand some people thinking you would sail off the edge of the earth 500 years ago than anyone in the USA thinking there is any serious debate about evolution (there are parts of the world where the educational system does not give everyone a chance to see the available evidence, so I can forgive some in the world for being ignorant – not having been exposed to the evidence). And I guess there are parts of the USA educational system that are nearly so poor also where a gullible student could not see the truth. But in the USA the evidence is easily at hand – you have to intentionally remain ignorant to somehow not understand the truth of evolution.

What Everyone Should Learn:

Dr. Vincent Cerf: “I would want people to really understand the theory of evolution and the origin of species. The power of cumulative, adaptive change in the genome, over the course of billions of years and changing conditions, is hard for many people to fully appreciate.”

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 🙂

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

Evolution In Action

the way they watched the process was to sequence the whole genome of each bacterial isolate. What they found were a total of 35 mutations, which developed sequentially as the treatment continued (and the levels of resistance rose). Here’s natural selection, operating in real time, under the strongest magnifying glass available. And it’s in the service of a potentially serious problem, since resistant bacteria are no joke. (Reading between the lines of the PNAS abstract, for example, it appears that the patient involved in this study may well not have survived).

The technology involved here is worth thinking about. Even now, this was a rather costly experiment as these things go, and it’s worth a paper in a good journal. But a few years ago, needless to say, it would have been a borderline-insane idea, and a few years before that it would have been flatly impossible. A few years from now it’ll be routine, and a few years after that it probably won’t be done at all, having been superseded by something more elegant that no one’s come up with yet. But for now, we’re entering the age where wildly sequence-intensive experiments, many of which no one even bothered to think about before, will start to run.

Very interesting. He is exactly right that the technology advances continuing at an amazing pace allow for experiments we (at least I) can’t even imagine today to become common in just a few years. And the insights from those experiments will allow us to think of new experiments… Wonderful.

‘Virtually untreatable’ TB found

‘Virtually untreatable’ TB found:

TB presently causes about 1.7 million deaths a year worldwide, but researchers are worried about the emergence of strains that are resistant to drugs.

Drug resistance is caused by poor TB control, through taking the wrong types of drugs for the incorrect duration.

Multi-drug resistant TB (MDR TB), which describes strains of TB that are resistant to at least two of the main first-line TB drugs, is already a growing concern.

Globally, the WHO estimates there are about 425,000 cases of MDR TB a year, mostly occurring in the former Soviet Union, China and India.

Evolution in Darwin’s Finches

“Instant” Evolution Seen in Darwin’s Finches, Study Says by Mason Inman

In 1982 the large ground finch arrived on the tiny GalÃ¡pagos island of Daphne, just east of the island of San Salvador (map of the GalÃ¡pagos).

Since then the medium ground finch, a long-time Daphne resident, has evolved to have a smaller beak—apparently as a result of direct competition with the larger bird for food.

Evolutionary theory had previously suggested that competition between two similar species can drive the animals to evolve in different directions.

But until now the effect had never been observed in action in the wild.
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Jonathan Losos is an evolutionary ecologist at Harvard University in Boston, Massachusetts, who was not involved with the Grants’ work.

“This study will be an instant textbook classic,” he said.

Two Butterfly Species Evolved Into Third

Butterfly photo

Two Butterfly Species Evolved Into Third, Study Finds by James Owen, National Geographic News:

Researchers say their creation reveals a process called hybrid speciation, in which the genes of two existing species combine to produce a third.

The study suggests hybridization may be more important to the evolution of new animals than had previously been thought.

Hybrids such as the mule, a cross between a donkey and a horse, are sterile. But the team says the butterfly hybrid brought together a combination of genes that allowed it to breed and there be considered a new species.

Evolution of Antibiotic Resistance

Inhibition of Mutation and Combating the Evolution of Antibiotic Resistance from the Public Library of Science Biology Journal:

The emergence of drug-resistant bacteria poses a serious threat to human health. In the case of several antibiotics, including those of the quinolone and rifamycin classes, bacteria rapidly acquire resistance through mutation of chromosomal genes during therapy. In this work, we show that preventing induction of the SOS response by interfering with the activity of the protease LexA renders pathogenic Escherichia coli unable to evolve resistance in vivo to ciprofloxacin or rifampicin, important quinolone and rifamycin antibiotics. We show in vitro that LexA cleavage is induced during RecBC-mediated repair of ciprofloxacin-mediated DNA damage and that this results in the derepression of the SOS-regulated polymerases Pol II, Pol IV and Pol V, which collaborate to induce resistance-conferring mutations. Our findings indicate that the inhibition of mutation could serve as a novel therapeutic strategy to combat the evolution of antibiotic resistance.

DNA Offers New Insight Concerning Cat Evolution

DNA Offers New Insight Concerning Cat Evolution, Nicholas Wade, New York Times:

Before DNA, taxonomists had considerable difficulty in classifying the cat family. The fossil record was sparse and many of the skulls lacked distinctiveness. One scheme divided the family into Big Cats and Little Cats. Then, in 1997, Dr. Johnson and Dr. O’Brien said they thought most living cats fell into one of eight lineages, based on the genetic element known as mitochondrial DNA.

Having made further DNA analyses, the researchers have drawn a full family tree that assigns every cat species to one of the lineages. They have also integrated their tree, which is based solely on changes in DNA, with the fossil record. The fossils, which are securely dated, allow dates to be assigned to each fork in the genetic family tree.
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The leopard lineage appeared around 6.5 million years ago in Asia. The youngest of the eight lineages, which led eventually to the domestic cat, emerged some 6.2 million years ago in Asia and Africa, either from ancestors that had never left Asia or more probably from North American cats that had trekked back across the Bering land bridge.

Photos from Curious Cat Travel Photos – Kenya