Archive for the 'General Science' Category

Jan 22 2016

Answering Questions About GMOs

Published by under General Science

CitrusGreening1I hadn’t planned on writing about GMOs again today, but I received an e-mail from a listener of the SGU which nicely represents common misconceptions that many people have about genetically modified organisms and farming in general. These are common anti-GMO talking points, which is why they are so widespread.

That even thoughtful skeptics have these concerns is testimony to the successful misinformation campaign waged by the anti-GMO movement, which is largely the organic lobby and some in the environmental movement, such as Greenpeace.

The strategy here is also clear – whenever you deal with one misconception about GMOs, opponents just slide over to another point which becomes the “real” reason they are against GMOs. The experience is identical to arguing with those who reject the claims of anthropogenic global warming, when forced to give ground on one factual claim (OK, maybe the Earth is warming), they just retreat to another (but do we know that this is bad?).

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39 responses so far

Jan 15 2016

Arctic Humans 45,000 Years Ago

Published by under General Science

mammothEMBEDThe dating of phenomena in the past, such as the existence of a specific species of animal or the presence of humans, is always based upon the earliest and latest evidence discovered so far. When you think about it, it is obviously very unlikely that we will have discovered the absolute earliest or latest occurrence of anything in the past.

It it therefore very common for new discoveries of fossils or archaeological evidence to increase the range of a phenomenon. Date ranges are always tentative and changing, although new discoveries still often lead to headlines emphasizing how surprised scientists were at the find.

For example, when did humans first live in the Arctic circle? There are essentially three types of evidence for a human presence. The first is direct evidence – human fossils found in the location and dated to a specific time. The second is human artifacts, stone tools being the most common because they preserve well and are unambiguous human artifacts. The third is human activity, such as fire pits or butchered animals.

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Jan 14 2016

Real Scientific Literacy, Part II

Dr_Nick_Simpsons-e1310873491586Continued from Part I

5) How to Analyze a Scientific Study

I don’t expect a non-scientist, or even a scientist far outside their area of expertise, to be able to do a detailed analysis of the strengths and weaknesses of a study. That is what peer-review is for. However, there are some basic rules of thumb that could give even a lay person a rough idea how seriously they should take a study. Always ask at least the following questions:

Is the study controlled in some way? Was the treatment group compared to a control group, or was the alleged effect compared to some baseline?

Is the study blinded? Were the primary measurements or assessments performed by someone who was blinded to whether or not the alleged effect is supposed to be present?

Are the outcomes being measured subjective or objective? How are they being measured? What do they really mean?

How large is the study? Studies with small numbers of subjects or measurements (less than 50 per group is a good rule of thumb) are considered small and unreliable.

Is the study an observation or an experiment? Are they just looking for some correlation  (in which it is difficult to make statements about cause and effect), or are they controlling for variables and isolating the one factor of interest?

What is the reaction of the scientific community to the study? Are experts generally critical or excited about the results? Continue Reading »

143 responses so far

Jan 12 2016

Real Scientific Literacy

miracleequationWhat does it mean to be scientifically literate? There is no completely objective answer to this question, it can be defined in multiple ways and the bar can be set anywhere along a spectrum.

Many tests of scientific literacy essentially ask a series of scientific facts – they are tests of factual knowledge, but not scientific thinking. This glaring deficit has been pointed out many times before, and was so again in a recent editorial by Danielle Teller. She writes:

There are a number of problems with teaching science as a collection of facts. First, facts change. Before oxygen was discovered, the theoretical existence of phlogiston made sense. For a brief, heady moment in 1989, it looked like cold fusion (paywall) was going to change the world.

I agree. A true measure of scientific literacy should be a combination of facts, concepts, and process. Facts are still important. Concepts without facts are hollow, and facts without concepts are meaningless. Both need to be understood in the context of the process that led us to our current conclusions.

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17 responses so far

Jan 11 2016

Should There Be Mandatory GMO Labeling?

GMO labelCampbell Soup has just announced that they are switching sides in the GMO labeling debate – they are now in favor of federal mandatory labeling for all products that contain genetically modified organisms. This has perhaps opened up a new chapter in the debate.

In response Mark Lynas, a journalist who, after researching the topic, is staunchly pro-GMO, has responded with an interesting essay agreeing with this move by Campbell.

Let me state up front that I think the answer to mandatory labeling is no, but let me also walk you through my thinking on this complex issue.

The Scientific Case Continue Reading »

124 responses so far

Dec 17 2015

Faking Peer-Review

Published by under General Science

I think we just have to face it – humans are cheaters. It’s in our nature.

We are also complex social creatures. The result, according to psychological research, is that most people will engage in small cheats if given the chance and they think they will get away with it. Various studies show, for example, that 75-98% of high-school and college students cheat at least once during their careers.

This makes sense given that we evolved in a resource-limited situation. There was an ever present real risk of starving to death, and so the willingness and ability to sneak a little extra food from the group would have had a distinct survival advantage.

At the same time there was a survival advantage to defending oneself against cheating, and living in groups meant that the group could defend against cheating using social pressure. Humans are therefore conflicted – we want to cheat but we feel bad about it because we also have a feeling of disgust toward cheating in order to pressure others into not cheating. We feel guilty and fear the shame of getting caught. When you balance all these things out, most people will cheat a little when they can get away with it. Those who cheat more are better at rationalizing their own cheating. Increased cheating may also result from greater pressure to perform, overcoming the social pressures against cheating. Continue Reading »

7 responses so far

Nov 30 2015

Anti-Environmental Opposition to GMO Salmon

Published by under General Science

The FDA just approved the first GMO animal for human consumption – AquAdvantage Salmon. Those ideologically opposed to GMOs have predictably opposed this approval, and now are calling for labeling. Meanwhile some food outlets, like Costco, Trader Joe’s, Whole Foods, Safeway and Korger, have pledged not to sell the fish.

This is a great example of how ideological thinking leads to irrational and self-contradictory positions.  Other than the fact that they were produced using genetic modification technology, these salmon are a wet dream (pun intended) of sustainable and environmentally friendly food production. ]

AquAdvantage Salmon

Salmon evolved a growth pattern that fits their seasonal migrations and their overall life cycle. There are several species of salmon, some Atlantic, some Pacific, and some exclusively fresh water. Atlantic salmon are the most common in fish farms.

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26 responses so far

Nov 12 2015

Nutrient Density of Crops Over Time

Published by under General Science

A new video is making the rounds on social media making the incredible claim that you would have to eat five grocery store apples today to equal the nutrient density (not calories, but other nutrients) of a grocery store apple from 1936. The video makes a second claim, that the decrease in nutrient density is due to poor soil. The video is little more that pro-organic propaganda, and neither claim is sourced – because they are not true.

However, the story of nutrient density of fruits and vegetables is a complex and interesting one. It is interesting to compare food plants from thousands of years ago (prior to any cultivation), 100 years ago, and today. First we need to ask – what are the differences? Then we can try to explain them.

Let’s compare first fruits and vegetable from today to 50 and 100 years ago.  A systematic review by Donald David found:

Recent studies of historical nutrient content data for fruits and vegetables spanning 50 to 70 years show apparent median declines of 5% to 40% or more in minerals, vitamins, and protein in groups of foods, especially in vegetables.

So there does appear to be a real decline, although not the 80% across the board suggested by the pro-organic video. The declines are significant for vegetables, and less so in fruits (so apples was a poor example to use). Averaging out all the declines, you get about a 20% decline in nutrient density for produce.

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144 responses so far

Sep 15 2015

Solar Hydrogen and our Energy Infrastructure

Published by under General Science

We are at an interesting point in our civilization. It seems pretty clear that the fossil fuel infrastructure on which our technology is largely built is not sustainable. Pulling massive amounts of conveniently stored energy out of the ground fueled the industrial revolution, and continues to be the primary source of our energy. Currently fossil fuels produce 82% of the worlds energy.

However, putting all that sequestered carbon back into the atmosphere is having unintended consequences on the climate. A recent estimate indicates that if we burn all the remaining known fossil fuel reserves the Antarctic ice sheet will essentially melt raising the oceans by 60 meters. Even if they are off by an order of magnitude, a 6 meter rise in sea level will dramatically alter the coastlines of the world.

Even if we put aside climate change, burning fossil fuels produces pollution. Beijing’s atmosphere is a good example of what happens when you try to fuel an industrial revolution with coal. Further, fossil fuels are finite. We can argue about how much there is available in the world, but it’s not infinite.

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39 responses so far

Sep 10 2015

The Arctic Sea Ice Hubbub

Published by under General Science

Those who accept the consensus that the Earth is warming due to human activity (anthropogenic global warming or AGW) point to declining Arctic sea ice as one line of evidence to support this conclusion. Those who do not accept the AGW consensus claim that Arctic sea ice is not declining, or at least we have insufficient data to reach such a conclusion.

What I like about this controversy is that it is about data. It is a fake controversy, driven by political ideology, but none-the-less we can sink our teeth into the data and see which side has the better position.

Arctic sea ice varies throughout the year, growing in the winter and melting in the summer. Therefore any year-to-year comparisons need to take this seasonal variation into account. Scientists use the summer minimum as one measure of the extent of Arctic sea ice for that year. You can also look at the winter maximum.

Sea ice can be measured in square miles, essentially the amount of area covered by ice. It can also be measured in thickness, and the two measures can be combined to calculate the overall volume of ice.

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55 responses so far

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