February 24, 2015
DNA Phenotyping To Make Drawings Of Criminal Suspects
Phenotype is what effect a gene has. So a genetic variant could cause black hair or blue eyes. Those are both phenotypes. A flood of genetic data caused by a many orders of magnitude decline in genome sequencing costs has led to the discovery of many genetic variants that control how our bodies develop and how we look. With only a DNA sample some companies can now computer generate a drawing of a criminal suspect.
Already genetic sleuths can determine a suspectís eye and hair color fairly accurately. It is also possible, or might soon be, to predict skin color, freckling, baldness, hair curliness, tooth shape and age.
This is still very much a work in progress. For example, while hundreds of genetic variations for height have been found the known variants probably aren't a complete list and their interactions are likely complicated. The same is true for genetic variants that control other visible traits such as bone shape in the face, hip width, bone thickness, size of hands, ratio of torso to leg length, and a great many other visible attributes. For example, imagine two variants that have the same net effect so that when both are present it is the same as when only one is present. Or two genetic variants might work synergistically to amplify some effect that they each cause separately.
Whatever the limits of the technology today, every year the accuracy of genetic tests for predicting facial shape will rise. As the number of people who've had complete genome sequencing rises into the hundreds of thousands and millions scientists will get enormously larger data sets to use to detect genetic variants that shape the face, shape teeth, determine hair textuure, eye brow thickness, lip thickness and shape, ear shape, and a great many other physical attributes.
All these genetic variants used to create increasingly more accurate sketches of criminals will be used for a more revolutionary purpose as well: embryo selection. I think we are getting close to the point where many couples are going to start to use in vitro fertilization (IVF) because of the ability to select for desired genetic traits in their offspring. Want your son to be taller than you and your husband? Select the embryo that will give you the tallest baby. Or select the embryo that will make the baby's eyes green or blue. Or go for a very pretty facial shape for your daughter.
I expect genetic test results will be used in mate selection. If the guy won't willingly share his genetic profile she could surreptitiously get a genetic sample and send it out for testing to a foreign lab. Then go online to a server that will show her likely combinations of their genes and what sorts of children will come as a result.
Randall Parker, 2015 February 24 07:49 PM
DNA is already used in mate selection, sort of. Those of Ashkenazi Jewish descent who may be at risk of having Tay-Sachs children who are interested in possible marriage can send off a DNA swab. They either get an "OK" or a "we don't recommend marriage" without saying much more. The implication is, of course, that each carries a single Tay-Sachs gene and therefore have a 1 in 4 chance of any child having the disease. It's horrible, so I understand that now most potential mates are checked out.
The real test would be to see how accurate a DNA test would identify identical twins. If its not 99% accurate it fails.
Prediction: Parents who opt for tall, brilliant, and beautiful will probably only have one kid. Parents who opt for pleasant and easily amused will be more likely to have several.
And there will be one parent who will have the final say on whatever occurs and that will be the one that lugs the fetus around inside their body. And if there are people who don't like that fact they should stop whining about it and man up and grow a vagina. So for now at least, women's choices are going to have much more of an effect on what happens than men's.
Identical twins show the limits to determining what people look like from their DNA. Identical twins don't necessarily look completely the same and the differences tend to accumulate with age.
there will be one parent who will have the final say on whatever occurs and that will be the one that lugs the fetus around inside their body.
In other words, the Arabs will suddenly have a very big advantage over the West in quality of offspring without sacrificing quantity.
EP, you're goinng to have to walk me through that. Are you saying that countries comprised mostly of people of Arab ethnicity have an advantage over other countries when it comes to making decisions about human genetic selection or engineering? Or are you just saying they are more likely to embrace these procedures more rapidly and use them more extensively than in other countries? Or something else entirely? I do know Saudi Arabia is a bit of a world leader in genetic testing for sickle cell anemia and thalassemia, but I'm not sure that wide spread genetic counselling will carry over to support for more active steps to control or alter human genetics.
I notice that people here keep commenting like this is the *last* genetic technology to affect how people decide on their children. It is *far* from the last, and only one in a sequence stretching into the future. Indeed, it will probably be relatively minor compared to the genetic engineering of human zygotes, that will be available to all within the next 15 years.
Thus, predictions about wonderful or dire long-term effects of this single technical change are vastly overblown. Humans like baby faces, so we will keep making them. We will also keep changing the way we make them for some decades into the future.
I'm saying that Muslims (which most Arabs are) don't let their women have much input into decisions about offspring.
The company is overstating how good its data is.
23andme doesn't even get hair/eye color and hair curliness right for white people. For me, one of these is just wrong, and one slightly off.
Facial features will be even harder.
Currently IQ predictions are also very weak. If you have every single one of the good IQ genes from the recent study your predicted IQ is 101.5, if have none it is 98.5.
Cystic fibrosis, like Tay Sachs, is also an autosomal recessive disorder, and 1 in 30 whites are carriers, making it the most common such severe genetic disease in America.
We are getting close to start to use in vitro fertilization (IVF) because of the ability to select for desired genetic traits in our offspring. But it is likely crossing the limit of nature. Finally it would have bad impact on human being.