Category Archives: Education

DNA Passed to Descendants Changed by Your Life

How your behaviour can change your children’s DNA

Until recently that would also have been the opinion of most scientists. Genes, it was thought, were highly resilient. Even if people did wreck their own DNA through bad diet, smoking and getting fat, that damage was unlikely to be passed to future generations.

Now, however, those assumptions are being re-examined. At the heart of this revolution is a simple but controversial idea: that DNA can be modified or imprinted with the experiences of your parents and grandparents.

According to this new science, known as epigenetics, your ancestors’ diet, smoking habits, exposure to pollutants and levels of obesity could be affecting you today. In turn, your lifestyle could affect your children and grandchildren.
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If we drink heavily, take drugs, get fat or wait too long to reproduce, then epigenetics might start tying up some of the wrong genes and loosening the bonds on others. Sometimes those changes will affect sperm and egg cells.

It seems to me this area is still far from having conclusive proof. But it is another great example of scientists seeking to improve our knowledge of how things work.

Leopard Bests Crocodile

Leopard savaging a crocodile caught on camera:

A series of incredible pictures taken at a South African game reserve document the first known time that a leopard has taken on and defeated one of the fearsome reptiles. The photographs were taken by Hal Brindley, an American wildlife photographer, who was supposed to be taking pictures of hippos from his car in the Kruger National Park.

The giant cat raced out of cover provided by scrub and bushes to surprise the crocodile, which was swimming nearby. A terrible and bloody struggle ensued. Eventually, onlookers were amazed to see the leopard drag the crocodile from the water as the reptile fought back.

Eventually the big cat was able to sit on top of the reptile and suffocate it. In the past, there have been reports of crocodiles killing leopards, but this is believed to the first time that the reverse scenario has been observed.

Fixing the World on $2 a Day

MIT’s Guru of Low-Tech Engineering Fixes the World on $2 a Day

The charcoal project is the responsibility of Mary Hong, a 19-year-old branching out beyond her aerospace major this semester. She and the other students, coincidentally all women, are enrolled in Smith’s D-Lab, a course that is becoming quietly famous beyond the MIT campus in Cambridge, Mass. The D is for development, design and dissemination; last fall, more than 100 students applied for about 30 slots. To prepare for their field work, D-Lab students live for a week in Cambridge on $2 per day. (Smith joins in.) Right now, eight more D-Lab teams are plying jungle rivers, hiking goat trails and hailing chicken buses in seven additional countries—Brazil, Honduras, Ghana, Tanzania, Zambia, India and China. In Smith’s view, even harsh aspects of Third World travel have their benefits. “If you get a good bout of diarrhea from a waterborne disease,” she says, “you really understand what it means to have access to clean drinking water.”
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Despite their simplicity, Smith’s creations made her a minor celebrity at MIT, and in 2000 she became the first woman to win the $30,000 Lemelson-MIT Student Prize. The same year, she began teaching full time at the university. It was nearly 30 years since German economist E.F. Schumacher had published Small is Beautiful: Economics as if People Mattered, the book credited with launching the appropriate technology movement. Schumacher argued that many of the infrastructure projects funded by the World Bank and other organizations hadn’t improved lives on the village level. “He rightly and aptly pointed out that big solutions don’t fit for villages. You have to make it small,”

Finding the Host Genes Viruses Require

Flu-infected fly cells reveal dependencies of the virus

The new study is important because it demonstrates a rapid-fire technique for identifying host factors such as proteins and carbohydrates that a virus commandeers to successfully infect a cell. By exposing the virus’s dependencies, the Wisconsin team has uncovered a target-rich environment for influenza drug developers.
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By working in fly cells, the Wisconsin team was able to deploy a technique to rapidly and selectively silence thousands of genes to see which were used by the flu virus. Screening a library of some 13,000 genes, the group identified more than 100 whose suppression in fly cells hindered the virus’s ability to successfully take over the cell and make new viruses.

Beloit College: Girls and Women in Science

photo of chemistry lab

Girls and Women in Science at Beloit College in Wisconsin:

sixth grade girls, along with their teachers and parents. This award winning conference encourages the exploration of science and mathematics by middle school girls through two days of experiments, activities, and interaction with science professionals. The girls, teachers, and parents will work with Beloit College faculty, students, and alumnae.

Girls getting into science

Eaton said the 24 girls participating will be able to take an active role in the laboratories. It’s critical the girls are encouraged and get the chance to increase their risk-taking abilities without boys.

The problem is, Eaton said, that sixth-grade girls’ interest in science starts dwindling and boys start becoming more dominant. “The boys take over the hands-on projects and the girls take notes,” Eaton said. “Boys will answer a question more authoritatively. Girls pose answers as a question. They are not as confident in their answers.”

To help foster activity among girls, the weekend conference also offers several workshops for parents and teachers. The workshops teach adults what they are doing to discourage girls and how they can learn to encourage them more.

2 Mysterious Species in the UK

Plane Bug - UK

Mystery insect found in Museum garden

This mystery bug has not been seen in the UK before and has made the Natural History Museum’s Wildlife Garden its home. The tiny bug is baffling insect experts at the Museum who are still trying to identify the mystery newcomer. The almond-shaped bug is red and black and about the size of a grain of rice
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Experts checked the new bug with those in the Museum’s national insect collection of more than 28 million specimens. Amazingly, there is no exact match.
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The bug closely resembles the fairly rare species Arocatus roeselii, which is usually found in central Europe. However, the roeselii bugs are brighter red than this new bug and they are usually associated with alder trees rather than plane trees.

However, the National Museum in Prague discovered an exact match to the mystery bug in their collections – an insect that was found in Nice and is classified as Arocatus roeselii. ‘There are two possible explanations,’ explains Barclay. ‘That the bug is roeselii and by switching to feed on the plane trees it could suddenly become more abundant, successful and invasive. The other possibility is that the insect in our grounds may not be roeselii at all.’

The Museum is working with international colleagues to analyse the bug’s body shape, form and DNA to see whether it is a newly discovered species or if it is in fact Arocatus roeselii.

Here is a green bug from my trip to Clifton Gorge Nature Preserve that is probably easier to identify. Or how about this insect from the Forest Glen Preserve, Illinois. Or how about this one at Our Lady of Gethsemani Abbey, in Kentucky.

Help us find out more about the mysterious alien “Ghost Slug”
Continue reading →

Speciation of Dendroica Warblers

Speciation for Dendroica Warblers

They developed a mathematical model that attributed patterns of speciation to the way that closely related species divide up their environment. According to this model, when there are few relatives around to compete for resources, such as when an environment is first colonized, species differentiate rapidly.
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This model is robust: even when the authors assumed that their phylogenetic tree contains only 25 percent of all Dendroica species, they found that their Î³ test was still valid, indicating that this genus experienced an explosive bout of adaptive radiation before settling down to a “more normal” rate of speciation.

This mathematical model provides an incisive tool to gain a clearer understanding of the pattern and rate of speciation for groups of closely related species, even in the absence of a fossil record, simply by analyzing their DNA.

A Whale of a Turbine

A whale of a turbine

a flipperlike prototype is generating energy on Canada’s Prince Edward Island, with twin, bumpy-edged blades knifing through the air. And this summer, an industrial fan company plans to roll out its own whale-inspired model – moving the same amount of air with half the usual number of blades and thus a smaller, energy-saving motor.

Some scientists were sceptical at first, but the concept now has gotten support from independent researchers, most recently some Harvard engineers who wrote up their findings in the respected journal Physical Review Letters.
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when models of the bumpy flippers were tested in a wind tunnel, Fish and his colleagues found something interesting. The flippers could be tilted at a higher angle before stall occurred.

The scientific literature had scant reference to the flipper bumps, called tubercles. Fish reasoned that because the whale’s flippers remained effective at a high angle, the mammal was therefore able to manoeuvre in tight circles. In fact, this is how it traps its prey, surrounding smaller fish in a “net” of bubbles that they are unwilling to cross.

In 2004, along with engineers from the US Naval Academy and Duke University, Fish published hard data: Whereas a smooth-edged flipper stalled at less than 12 degrees, the bumpy, “scalloped” version did not stall until it was tilted more than 16 degrees – an increase of nearly 40 percent.

Fish then partnered with Canadian entrepreneur Stephen Dewar to start WhalePower, a Toronto-based company that licenses the technology to manufacturers.
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It has all been a bit of a culture shock for Fish, who is more at home in the open world of academia than the more secretive realm of inventions and patents. Two decades ago, his only motivation was to figure out what the bumps were for.

“I sort of found something that’s in plain sight,” he says. “You can look at something again and again, and then you’re seeing it differently.”

500 Year Floods

Why you can get ‘500 year floods’ two years in a row by Anne Jefferson:

Flood probabilities are based on historical records of stream discharge. Let’s use the Iowa River at Marengo, Iowa as an example. It reached a record discharge of 46,600 cubic feet per second* (1320 m3/s) on 12 June. That flow was estimated to have a 500 year recurrence interval, based on 51 years of peak flow records
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When you are extrapolating beyond your data by an order of magnitude, the highest points in the dataset start to have a lot of leverage. Let’s imagine that there’s another big flood on the Iowa River next year and we do the same analysis. Now our dataset has 52 points, with the highest being the flood of 2008. When that point is included in the analysis, a discharge of 46,600 cubic feet per second* (1320 m3/s) has a recurrence interval of <150 years (>0.6%). It’s still a darn big flow, but it doesn’t sound quite so biblical anymore.
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Urbanization and the adding of impervious surface is one cause of increasing flood peaks, but in Iowa, a more likely culprit is agricultural.

This post is a good explanation that the 500 year flood idea is just way of saying .2% probability (that some people confuse as meaning it can only happen every 500 years). But I actually am more interested in the other factor which is how much estimation is in “500 year prediction.” We don’t have 500 years of data. And the conditions today (I believe) are much more likely to create extreme conditions. So taking comfort in 500 year (.2%), or even 100 year (1% probability) flood “predictions” is dangerous.

It would seem to me, in fact, actually having a 500 year flood actually increases the odds for it happening again (because the data now includes that case which had not been included before). It doesn’t actually increase the likelihood of it happening but the predictions we make are based on the data we have (so given that it happens our previous 500 year prediction is questionable). With a coin toss we know the odds are 50%, getting 3 heads in a row doesn’t convince us that our prediction was bad. And therefore the previous record of heads or tails in the coin toss have no predictive value.

I can’t see why we would think that for floods. With the new data showing a flood, (it seems to me) most any model is likely to show an increased risk (and pretty substantial I would think) of it happening again in the next 100 years (especially in any area with substantial human construction – where conditions could well be very different than it was for our data that is 20, 40… years old). And if we are entering a period of more extreme weather then that will likely be a factor too…

The comments on the original blog post make some interesting points too – don’t miss those.

The Brain Hides Information From Us To Prevent Mistakes

“The main finding of the study is that it has enabled us to confirm that tactile sensations are initially located unconsciously in anatomical coordinates, but they reach our awareness only when the brain has formed an image of their origin in the spatial coordinates, external to the body,” explained Salvador Soto-Faraco. The coexistence of different spatial reference frames in the brain has been known for some time. So has the fact that confusions between them may result in some cases, such as when we invert the usual anatomical position of some body parts (e.g. when crossing our arms over the body midline). “The brain sorts out problems of this kind rapidly, in a matter of tenths of a second. To do so, however, it has to integrate information arriving in formats that are quite disparate”, Sotoa-Faraco added. “Our research has helped us understand how this process works and how the brain manages spatial realignment when faced with conflict”, he concluded.

Interesting. I think my brain might be hiding more from me lately (like right now where the key to my shed is) 🙂