Wednesday, March 26, 2014

To DNA or not to DNA, that is the question...


DNA testing has become widespread in our society today. DNA is collected and analyzed by police and security forces around the world, newborn infants are routinely screened for a number of genetic conditions, lawyers make use of DNA in paternity suits, and genealogists are using it to solve family inheritance problems as well as to peer into their deep genetic roots. But questions, fears, and misconceptions arise in many people when they contemplate having their own DNA tested. What are the issues? Why are some people afraid to have a test? Here are some possibilities that have crossed my mind:

1. You are a crook or have committed some type of crime and don't really want anyone linking you to a crime scene. This is a valid concern and if you fit into this category, I would recommend you avoid getting a DNA test.

2. You plan to become a crook or felon in the near future. Again, a valid concern (see #1 above).

3. You are afraid that Johnny and Mary will find out that you are not really their biological father (or biological mother). This is also a legitimate concern and, again, if you fit into this category, I would recommend against getting a DNA test. Johnny and Mary, however, may be interested in the results of such a test.

4. You would really prefer not to know if you predisposed to get colon cancer or Alzheimer's disease. For many people life is much more pleasant if they have no idea what the future might hold. If you are one of these, then you probably do not want to get a DNA test, at least not one that reports back on your health tendencies. However, knowing that you might be susceptible could help you get early therapy and prevent these types of things from ever becoming a problem.

5. You have no interest in who you might be related to, and in fact, no interest in humanity in general. Yes, I agree, if this is your category, then DNA testing is not for you.

6. You are afraid that you might have more than your share of Neanderthal DNA. See my earlier post (Yes, I am a Caveman) on this issue if you fall into this category.

7. You are afraid that you will lose your health insurance if your DNA shows you have a predisposition toward certain diseases and conditions. This was a legitimate concern, but President Obama and the U.S. Congress have fixed things. Now, the more preexisting conditions you have the easier it is for you to get insurance. It's those of us who are healthy most of the time that have to worry.

8. You are afraid that your identity will be more easily stolen. This is, of course, just the opposite of the truth. Your DNA is completely unique to you and cannot be stolen by anyone else. Someone can easily duplicate your ID cards, they can get a hold of your bank accounts, they can even have plastic surgery to make themselves look just like you, but they cannot steal your DNA.

For more information of DNA testing, here are a couple of good articles:
 Come back soon for my take on the DNA tests and services offered by the three main companies that do it for genealogical purposes: FamilyTree DNA, 23andMe, and AncestryDNA.

Wednesday, March 12, 2014

Yes, I'm a Caveman!

The truth will come out sooner or later, so I may as well come clean now. I just received results from my latest DNA test performed by the company 23andMe and the good news is that I am 96.8% human. I know that some of you, particularly my close acquaintances and family members, think that percentage is a bit too high. You would have predicted that my human percentage might be closer to 15%, but no, it's 96.8%.

The bad news is that the other 3.2% is not human, at least not in the sense of the modern human as we know them today. The other 3.2% is Neanderthal. Now it's bad enough that I'm 3.2% Neanderthal, but that's not even the worst part. The worst part is that at 3.2% I am in the 99th percentile of all the people that have been tested. What that means is out of every 100 people tested, 99 of them have less Neanderthal DNA than I do! That's right...just go ahead and start making jokes. Why my brother-in-law Steve was making them last Sunday even before I got the test back. Now I am going to have to admit that he was right.

You can see in this graphic from 23andMe that they have perfectly described me: heavy eyebrow ridges, long, low but bigger skull, prominent nose, and scant clothing. Here is a recent picture:

But, perhaps it won't be so bad. I can perhaps get some work in commercials. I understand that Geico, Inc. is looking for a new caveman, one with a bit more of the real caveman look.

Saturday, March 8, 2014

Normal Weather?

Meteorologists, TV weathermen, and state and local water planners have convinced the general public that there is something called "Normal Weather." The implication of this is that anything other than "Normal Weather" is "Abnormal." But there is no such thing as normal weather in the sense that most people think of normal. Indeed, what meteorologists mean when they say normal is AVERAGE. "Average Weather" makes perfect sense, but unfortunately the general public is so stuck on normal and this terminology is so ingrained in the media that it is unlikely to change. To give due credit to many professional meteorologists and meteorological organizations, they have tried to use the term average instead of normal, but on TV and in newspapers normal is still used almost exclusively.

The problem with using NORMAL is that the general public expects that temperature or rainfall or number of hurricanes or other weather phenomena should, most of the time, fall into the normal category. This is simply not the case. For a given month, day, or year to actually hit right onto the value touted in the media as normal is a fairly uncommon event. Most days, months, and years the temperatures and rainfall are either less than or more than the normal value. And yet the media continue to broadcast these statistics as if we should be getting the normal amount.

In speaking of the recent storms that have helped a bit with the water situation in California, one web site stated: "Thanks to the most recent rounds of rain and snow throughout California, Los Angeles and San Francisco both received at least 86 percent of their normal rainfall for the month of February. However, farther south, San Diego only received 44 percent of the city's normal precipitation for February."

It sounds from these reports that 86 percent of normal or 44 percent of normal is abnormal, like California deserves to at least get a normal amount of precipitation and if they get anything less or more then someone has really messed up. But how likely is it that California will get only 86 or 44 percent of "normal" precipitation? Meteorologists like to calculate a measure called the Coefficient of Variation to help determine this likelihood. The coefficient of variation is related to the standard deviation of rainfall at a particular station and in essence tells us that if the coefficient is 0.24, for example, then at that station the average rainfall would be expected to vary by 24% in 67% of the years (1 standard deviation on a bell curve). This coefficient varies at different locations across the state of California, but here is a list of a few places provided by another web site:

Station in California (Climate Zone)
Coefficients of Variation
Klamath (Marine West Coast)
Eureka (Marine West Coast)
Fort Bragg (Marine West Coast)
Chico (Mediterranean)
San Francisco (Mediterranean)
Monterey (Mediterranean)
Spreckels (Mediterranean)
Santa Barbara (Mediterranean)
Los Angeles (Mediterranean)
San Diego (Mediterranean)

So in Los Angeles, rainfall will vary by up to 47% from average 67% of the time. It also means that 33% of the time (one-third of the years) rainfall will vary by more that 47%. Since Los Angeles received 86% of it's average rainfall in February, then it is only 14% from its average value and well within the coefficient of variation.

I don't suppose this is a battle I will ever win. The media will continue to use normal instead of average, water planners will continue to use normal in their future plans, and the general public will continue to expect "normal" to happen and be disappointed when most of the time it does not. But perhaps a few will realize that if we expect normal to happen, we are fooling ourselves.