Article: Airplane Poop Could Help Track Global Disease Outbreaks

IN THE SUMMER of 2013, researchers at the Technical University of Denmark headed to the Copenhagen airport for a special delivery: poop. The crew who clean out airplane toilets had siphoned it from flights arriving from around the world just for them. 

Back in the lab, the researchers turned the samples into DNA soup and fed them through a sequencing machine. Out the other end came antimicrobial resistance genes and potential pathogens—all traceable to the individual plane’s country of origin.

[snip]

From the airplane waste, the Danish researchers could identify regional patterns. Genes for antimicrobial resistance, for example, were more abundant in samples from South Asia than North America. They found differences in specific bacteria, too: Salmonella enterica, which can cause diarrhea, was more common in South Asian samples while Clostridium difficile, the bacteria behind a difficult-to-treat hospital-acquired infection that often follows a course of antibiotics, was most common in North American samples. 

Article: Genes influence academic ability across all subjects, latest study shows [Update: Eugenics 2.0]

Around 60% of differences in GCSE results can be explained by genetic factors, with the same genes responsible for maths, science and the humanities 

The study suggests that a weakness in one subject is most likely to be caused by environmental factors, such as teaching, as the genes affecting ability for different subjects are the same. 

Results in all subjects, including maths, science, art and humanities, were highly heritable, with genes explaining a bigger proportion of the differences between children (54-65%) than environmental factors, such as school and family combined (14-21%), which were shared by the twins.

The article linked below suggests that inheritability of homosexuality is about about 35%; or, in other words, about half the inheritabilty of academic ability (including intelligence, memory, diligence, and curiosity).

I found this article in a post I will not link to. One of the points that the author makes is that "eugenics 2.0" is inevitable. Eugenics 2.0 will target the bearers of specific genes; for example, those involved in violence or low academic ability. While there will be a disparate impact in terms of race and ethnicity, eugenics 2.0 advocates will be able to declare that their motivation will not be racism. Eugenics 1.0, an enterprise of early 20th century Progressives, openly advocated sterilizing of the "unfit" and controlling the population of inferior races. Eugenics 2.0 will not have to and still acheive the same result.

Update: National Security Will Drive Genetically Enhanced Offspring

Eugene Volokh thinks the US will feel pressure to allow offspring IQ boosting or fall behind other nations. It becomes a national security issue if the American population becomes 20 IQ points lower than China, India, and Russia. So expect the national wing of a nation's elites to promote offspring genetic engineering. 

In spite of the outliers I expect offspring genetic engineering will lead to brighter, better looking, higher performing, and healthy children and adults. What I'm less sure about is personality traits and moral reasoning circuitry.  

[snip] 

Then the rate of human evolution will skyrocket. We live in the final decades of human wild type. Some day wild type humans will be the minority. In some countries that will happen in this century.

Article: The association between intelligence and lifespan is mostly genetic

Background: Several studies in the new field of cognitive epidemiology have shown that higher intelligence predicts longer lifespan. This positive correlation might arise from socioeconomic status influencing both intelligence and health; intelligence leading to better health behaviours; and/or some shared genetic factors influencing both intelligence and health. Distinguishing among these hypotheses is crucial for medicine and public health, but can only be accomplished by studying a genetically informative sample.

A long standing, and powerful, assumption among many people is that human beings are born as a "blank slate" and that any differences in outcomes among individuals or various socioeconomic groups must be due to disadvantages and oppression. This is another nail in the coffin of that pernicious paradigm.

Key Messages

• It has been reported that brighter people live longer; we asked ‘why?'.
• We found, using data from three studies, that the small association between being brighter and living longer was mostly genetic in origin.
• This is a key finding in cognitive epidemiology; it is a further indication that intelligence is not just ‘school-smarts'.

I like this also because it shows the scientific method in operation.

Observation: Brighter people live longer.
Problem: Why do brighter people live longer?
Hypotheses: This positive correlation might arise from
1. socioeconomic status influencing both intelligence and health;
2. intelligence leading to better health behaviours;
3. and/or some shared genetic factors influencing both intelligence and health.
Experiment: retrospective analysis of three, long-term twin studies
Results: a small association between intelligence and living longer is mostly genetic in origin.
Conclusion: "intelligence is not just ‘school-smarts'."

Hypothesis falsification:
Factoring in socioeconomic factors, and health behaviors, using data from Sweden, seems to indicate that these factors do not influence lifespan.

In other word, environmental factors have a smaller effect on life span than genetic factors, such as intelligence.

The biological transmission of memory.

Article: Phobias may be memories passed down in genes from ancestors

In the study, which is published in the journal of Nature Neuroscience, the researchers trained mice to fear the smell of cherry blossom using electric shocks before allowing them to breed. 

The offspring produced showed fearful responses to the odour of cherry blossom compared to a neutral odour, despite never having encountered them before. 

The following generation also showed the same behaviour. This effect continued even if the mice had been fathered through artificial insemination.The researchers found the brains of the trained mice and their offspring showed structural changes in areas used to detect the odour.

Up until recently, this would have been considered nonsense. Classical evolution and genetics stated that the experiences of the parent could not be transmitted to offspring. At its most extreme, evolution was seen as favoring only those genes that were most successful in passing themselves onto offspring. Genes could affect behavior, but not the other way around.

The DNA of the animals also carried chemical changes, known as epigenetic methylation, on the gene responsible for detecting the odour. 

This suggests that experiences are somehow transferred from the brain into the genome, allowing them to be passed on to later generations. 

The researchers now hope to carry out further work to understand how the information comes to be stored on the DNA in the first place. 

They also want to explore whether similar effects can be seen in the genes of humans.

We now know that this mechanism exists, though not how it works. How does changes in the brain change the DNA in cells of the ovary and testes that become eggs and sperm?

He added: "It addresses constitutional fearfulness that is highly relevant to [human] phobias, anxiety and post-traumatic stress disorders, plus the controversial subject of transmission of the ‘memory’ of ancestral experience down the generations.

Faces: pretty and intelligent

Article: You really CAN tell how intelligent a man is just by looking at him, scientists say (and the key is a long face and bigger distance between the eyes)

'The ability to accurately assess the intelligence of other persons finds its place in everyday social interaction and should have important evolutionary consequences,' the team wrote in the journal PLoS One.

If so, why be able to assess the intelligence of men, but not women? Over evolutionary time, have women been assessed on other values, instead? [See below]

The team used static facial photographs of 40 men and 40 women to test the relationship between measured IQ, perceived intelligence, and facial shape.

Both men and women were able to accurately evaluate the intelligence of men by viewing facial photographs, they discovered.

'These results suggest that a perceiver can accurately gauge the real intelligence of men, but not women, by viewing their faces in photographs; however, this estimation is possibly not based on facial shape,' they claim.

'Our study revealed no relation between intelligence and either attractiveness or face shape.

 Article:  In Harsh Conditions, Men Don't Want a Pretty Face

Big eyes and full lips may turn male heads in Japan, but in Nepal, men aren't as interested in pretty, girly faces.

Those are the findings of a new study of men's preferences for female faces in 28 nations. The results reveal that guys are drawn to feminine looks – large eyes, pillow lips and a soft jaw — to a greater extent in countries that are the healthiest.

The reason for this difference isn't clear, but scientists suspect that evolution may drive these attractions, at least subconsciously. Men in harsh conditions may have a better chance of fathering children who survive if they mate with a woman who can hold on to resources, said study researcher Urszula Marcinkowska

Seals, tuberculosis, and DNA

Article: Seals carried tuberculosis across the Atlantic, gave it to humans: Disease was present in the Americas prior to European contact.
This offers a glimpse at the rather complicated history of tuberculosis.

TB leaves recognizable changes in bones. Therefore, it can be the diagnosed from skeletons of the long dead.

In the Old World, the bacteria causing TB made the leap to humans about 10,000 years ago. After that, it made the leap from humans to cattle.

It is known that Native Americans had TB early on. This gave rise to the belief that Westerners brought it to the Americas. However, pre-Columbian skeletons were found showing the disease.

So, if the land bridge from Asia was submerged more than 10,000 years ago, how did the disease get here?

Turns out that bacterial DNA from three, 4,000 year old skeletons of Native Americans in Peru was not the normal, human variant. It was the "pinniped" variation. That is, seals carried TB from Africa to South America, and from there across the Americas.

Seals also carried TB to Australian Aborigines about 700 year ago.

Microevolution: Pygmies, butterflies, and Tibetans

Three articles about microevolution. That is, the rapid spread of a change in genes through a population because that change confers an advantage to those having the gene.

Article: Pygmy phenotype developed many times, adaptive to rainforest

The small body size associated with the pygmy phenotype is probably a selective adaptation for rainforest hunter-gatherers, according to an international team of researchers. But all African pygmy phenotypes do not have the same genetic underpinning, suggesting a more recent adaptation than previously thought.

Genetic mutations occur in populations all the time. If they have a negative impact on the individual, they tend to disappear from the population quickly. If they have no noticeable impact for the good or bad, they might disappear as well, although more slowly. Mutations which have positive influence on individuals, making them more fit for their environment, tend to spread through the population.

Article: Butterflies' evolutionary responses to warmer temperatures may compromise their ability to adapt to future climate change

Members of the brown argus butterfly species that moved north in response to recent climate change have evolved a narrower diet dependent on wild Geranium plants, researchers report. However, butterflies that did not move north have more diverse diets, including plants such as Rockrose that are abundant in southern parts of the UK.

Article: 8,000-year-old mutation key to human life at high altitudes: Study identifies genetic basis for Tibetan adaptation

In an environment where others struggle to survive, Tibetans thrive in the thin air of the Tibetan Plateau, with an average elevation of 14,800 feet. A new study is the first to find a genetic cause for the adaptation and demonstrate how it contributes to the Tibetans’ ability to live in low oxygen conditions.

About 8,000 years ago, the gene EGLN1 changed by a single DNA base pair. Today, a relatively short time later on the scale of human history, 88% of Tibetans have the genetic variation, and it is virtually absent from closely related lowland Asians. The findings indicate the genetic variation endows its carriers with an advantage.

Genetics and colonizing distance worlds

Article: Want to Colonize an Alien Planet? Send 40,000 People

One of the major obstacles to colonizing a distant planet has to do with genetics.

It would take at least 150 years to get from Earth to some other, colonizable world and thus at least 6 generations.

In order for the colony to be viable in the long term there has to be enough genetic variation to avoid what is called the "founder effect" or a "genetic bottleneck." Only having a small population to start with concentrates "deleterious" genes due to in-breeding.

The authors estimated that about 40,000 people would be necessary for such a long-duration space flight and for colonizing the world.

It would help if the population chosen would be made of people of diverse ethnic/racial backgrounds. 

One way in increase genetic diversity, not discussed, would be send along a large number of any of the following: sperm samples, frozen eggs, or embryos.

Race and aging

Article: Does your race determine your biological age? Controversial research claims black people age more quickly - and are up to THREE YEARS older in health terms

Authors: Morgan Levine and Eileen Crimmins of the University of Southern California’s Davis School of Gerontology. wrote in the journal Social Science and Medicine.

Yet another data point in the discussion about race.

How they did it:

The current study uses data on 7,644 black and white participants, ages 30 and above, from the third National Health and Nutrition Examination Survey.

The researchers calculated each participant’s 'biological age' by looking at 10 biomarkers that have been linked to aging, including C-reactive protein, serum creatinine, glycosylated hemoglobin, systolic blood pressure, and total cholesterol.

The team compared then compared biological ages of blacks and whites as indicated from the biomarkers.

Conclusions:

Black people age more quickly than white people, a controversial new study has claimed.

Researchers say that the researcher could shed new light on higher mortality rates in black people.

They say the biological age differences by race increase up until ages 60-69, and then decline.

Differences in biological age between blacks and whites appear to increase up until ages 60-65 and then decline, presumably due to mortality selection.

The team say the cause could be stress-related.

'Everyday stressors associated with being black may negatively impact physiological functioning and, under chronic exposure, accumulate over the lifespan and contribute to growing disparities in biological risk,' the authors wrote.

'Furthermore, if such environmental, behavioral, and mental factors contribute to an acceleration of the aging process, we would expect that persons who are aging the fastest should have the highest risk of mortality, and thus (have a) lower life expectancy.'

The hypothesis, that the aging may be stress related, can be tested by looking at the levels of those hormones that are related to stress in the same population.

Another hypothesis is obvious even if the authors/reporters will not touch it with a ten-foot pole. Race differences are hard-wired genetic differences. We already know that there are genetic components to aging. The difference in rate of aging may be due to genetic differences between blacks and whites.

This article links to the actual research paper.

I have posted a second discussion of this at the "Rooted in Him" blog: Should race matter to a Christian?

The genetics of chosing friends

Article: Genome-wide analysis reveals genetic similarities among friends

"Looking across the whole genome," Fowler said, "we find that, on average, we are genetically similar to our friends. We have more DNA in common with the people we pick as friends than we do with strangers in the same population."

The study is a genome-wide analysis of nearly 1.5 million markers of gene variation, and relies on data from the Framingham Heart Study. The Framingham dataset is the largest the authors are aware of that contains both that level of genetic detail and information on who is friends with whom.

On average, friends are as "related" as fourth cousins or people who share great-great-great grandparents. That translates to about 1 percent of our genes.

Friends are most similar in genes affecting the sense of smell. The opposite holds for genes controlling immunity. That is, friends are relatively more dissimilar in their genetic protection against various diseases.

Coffee is mentioned.

Oddly enough, married couples are reported to be dissimilar in immunity as well. The reason is not clear. It is suggested that it helps slow down the spread of diseases if parents differ in their ability to fight off different diseases. Perhaps the same mechanism is involved with friends as well.

Side note: The Framingham Heart Study began in 1948 with 5,209 adult subjects. It is now on its third generation of participants

Domestication syndrome and genes

Article: Domestication syndrome: White patches, baby faces and tameness explained by mild neural crest deficits

More than 140 years ago, Charles Darwin noticed something peculiar about domesticated mammals. Compared to their wild ancestors, domestic species are more tame, and they also tend to display a suite of other characteristic features, including floppier ears, patches of white fur, and more juvenile faces with smaller jaws. [This is called the domestication syndrome.]

... 

Why [does] breeding for tameness causes changes in such diverse traits[?] 

...

In the hypothesis proposed by Wilkins and co-authors Richard Wrangham of Harvard University and Tecumseh Fitch of the University of Vienna, domesticated mammals may show impaired development or migration of neural crest cells compared to their wild ancestors. 

... 

Tests of the neural crest hypothesis may not be far off, as other scientists are rapidly mapping the genes that have been altered by domestication in the rat, fox, and dog. The hypothesis predicts that some of these genes will influence neural crest cell biology.

This is a lovely example of the scientific method in operation. 

Darwin's observations are in the first paragraph. The problem is in the second. The hypothesis to explain the problem is in the third. A possible test of the hypothesis is in the fourth.
Wikipedia: Domesticated silver fox

Scientists in Novosibirsk, Russia began an experiment over 50 years which resulted in the first true, domesticated foxes.

Domesticated red fox, red variety

Domesticated red fox, silver variety.

The fox is an especially good test animal for this as the scientists in Novisibirsk, Russia, have three varieties of foxes: wild fox, their domesticated variety, and a variety selected for "wildness." The latter amplifies the wild traits of the fox.

Climate change, red hair and Scotland

Article: Climate change could make red hair a thing of the past if Scotland gets sunnier

Ludicrous, silly, ignorant; a trifecta of stupidity.

The author makes the argument that the red hair trait is adaptive because fair skin helps vitamin D to be made. It won't be necessary if Scotland gets more sun due climate change.

Maybe after several thousand years of increased sunniness due to climate change. Maybe if everyone had to live outside for most of their lives like their farming/herding ancestors did. Maybe if no one takes vitamin D supplements.  Maybe, suddenly, red haired women will no longer be considered attractive.

And I can only hope this is a misquote:

“If it was to get less cloudy and there was more sun, there would be fewer people carrying the gene.”

What would cause that? Wishful thinking?

Article: Tibetans didn't get their genetic advantage from Homo sapiens

Article: Here’s Why Tibetans Can Live Comfortably At Crazy-High Altitudes

Researchers have discovered they [Tibetan] share a gene with our hominid cousin the Denisovans, who went extinct some 40,000 years ago...

Known as EPAS1, the gene allows Tibetans to absorb scarce oxygen without creating extra red blood cells—something the rest of us mortals must deal with at altitude...

Another example of microevolution. A mating, or several, transferred the gene to the human population of the Tibetan Plateau. The gene then spread through the population because it conferred an advantage to those bearing it.