Image source @ Visual China
Text | Brain polar body
In the movie "Let the Bullets Fly", there is a particularly interesting plot:
Huang Silang, the lord of Goose City, held Zhang Mazi's certificate of appointment and was puzzled——
Huang: Is this picture of you?
Zhang: It's me.
Huang: This is not you.
Zhang: I also said that this TM is not me at all. I went to the photo studio to take a picture, and when I took the picture, they gave me this one, and I said it wasn't me, they said it was you, I said he wasn't me! They say this is you. No way, I just posted him here.
Therefore, Zhang Mazi took up his post like this.
Perhaps, you just think that this plot is particularly funny, which can be called large-scale reality magic. But in reality, looking for long-lost relatives, tracking down criminals who have caused the crime, etc., can only rely on this kind of easily forged and vague information, which will make the whole task useless.
Accurately identifying a person's identity and even appearance has become a key social problem that must be solved. The most convenient and safe solution today is undoubtedly DNA technology.
DNA in the human body is unique (identical twins may have the same DNA) and permanent, so DNA identification is also absolutely authoritative and accurate, and is currently one of the most widely used and mature criminal investigation techniques in the world, and has always been considered the gold standard for finding missing people.
Moreover, DNA information is difficult to completely erase, and a piece of clothing worn, a piece of chewed gum, and a fallen hair may be collected from a DNA sample. Imagine if the appearance can be directly depicted according to DNA, can you quickly get the key information, so as to speed up the pace of reunion and the progress of the case?
For example, the results of the recently closely watched results of the investigation into the Xiaohuamei incident in Xuzhou were announced, and the identity of Yang Mouxia, xiaohuamei, was confirmed through DNA test comparison. At the same time, some netizens compared the photos of Xiaohuamei and Yang Mouxia, and many people thought that they were not like the same person. In this case, if you can predict and generate a facial portrait through DNA, you may be able to see the facial features intuitively and accurately, effectively convincing the doubter.
In fact, the prediction of human external visible characteristics (EVCs) based on DNA information has long been applied to areas such as forensic identification. So, is it the "silver bullet" silver bullet that reopens the identity fog in the search for murder?
DNA to Face, is it reliable?
Globally, DNA phenotypes are an extremely important forensic tool. When the investigation is clueless, DNA phenotypes can extract certain genes from an individual's DNA to predict individual facial features, help determine what the perpetrator might look like, further narrow down the suspect, and speed up the investigation process.
For people who are eager to find relatives, DNA phenotypes can also help them quickly locate the face of potential relatives, exclude candidates who do not have relevant genetic variants at all, and help people reunite early.
(Parabon used DNA to reconstruct the face, a suspect who was later identified as a 1987 murder case.)
First, by analyzing the genetic variation point SNP, the body and facial features are determined. These point differences often affect a series of information related to the human body, such as eye color, hair color, age, sex, height, genetic diseases, etc. Therefore, by comparing SNPs, a sample of a person's facial feature data can be obtained.
Then, based on artificial intelligence algorithms and depth generation models, information related to physical features is extracted to create facial images. In order to ensure scientificity, each feature is often presented in the form of a percentage of accuracy. For example, the other person may have an 88.6% probability of being a white male, with an 88.3% probability of having brown eyes and a 22% probability of freckles.
In addition, even if the case has been around for years, DNA phenotypes can be combined with AI facial recognition technology to generate the appearance of the other party over time, or to restore the appearance of childhood. If a child has been missing for several years, a strand of hair removed from the child's comb can be used to create a set of images of age progression.
Ellen McRae Greytak, director of bioinformatics at DNA research firm Paraboon, has shared that the company has helped solve more than 200 cases over the past seven years.
In 2015, Colombian police used DNA collected at the scene to generate images of suspects, arrested a man, and finally cracked a homicide that had not progressed for four years.
3D images of the DNA phenotype show that the killer was supposed to be an African Algerian male with olive skin, green eyes, plump lips, and little or no freckles.
Images based on DNA, which can be combined with other investigative information to generate search or wanted posters, will undoubtedly make progress more effective.
Not a silver bullet, but a sharp knife
But in the eyes of ordinary people, this technology seems to be somewhat useful, and it seems to be useless.
Because, at present, DNA technology cannot accurately predict multiple facial features. The shape of the face is determined by thousands of genes, and the marking of a single feature in a single place may affect the entire facial performance, making the face shape change from masculine to feminine, and this ambiguity poses a challenge to subsequent tracing.
In addition, DNA phenotypes can only reflect genetic characteristics and cannot show interactions with the acquired environment. For example, hair coloring, nose cutting, tooth loss, etc., may change the appearance of the suspect, but it cannot be reflected in the DNA. So it is impossible to predict exactly what a person will look like based on DNA alone.
In addition, we all know that deep learning models rely on large-scale data set training, and in the current datasets of many facial recognition systems, the facial data of different races is not balanced, which will lead to very different recognition accuracy of different groups, and groups with low algorithm accuracy may be easily misjudged and convicted, bringing new injustices.
For example, in a 2019 DNA phenotypic study based on the Hapmap dataset, the GLOBAL cohort (global sample) performed less well than the EURO cohort (European sample), one of the reasons is that the Data scale of the European genome is larger, so the model is better recognized.
And wherever we go, we leave traces of our DNA, like a strand of hair left on the subway, or saliva on a glass in a café... When the readiness of DNA samples meets the application of market-based services and large-scale databases, this technology also creates huge privacy risks.
In 2013, New York-based artist Heather Dewey Hagborg launched an art project, Stranger Visions, to create portrait sculptures from genetic material collected in public places. For example, from a dropped cigarette butt, DNA showed that the smoker was a male of Eastern European descent with brown eyes.
(Dewey Haagburg collected a cigarette butt in New York at 12:15 p.m. on January 6, 2013))
She inputs these parameters into an algorithmic model, creates a 3D model of the face, and 3D prints the sculpture.
It's not hard to imagine that if this technology begins to be applied on a large scale, and DNA samples are everywhere, then it is likely that all your travels and what you have done will be cut off.
And this day has arrived. At present, many overseas bio-institutions and technology companies will provide similar services, such as Greytak, Parabon, Corsight, etc., Human Longevity has used DNA to reconstruct facial photos as early as 2017. It was through The Parabon NanoLabs program, Snapshot, that the Colombian police created the image of the suspect.
There are also easy-to-use facial DNA testing apps that can be downloaded for free online to help people determine their ancestry, determine parent-child relationships, and find relatives. The application Face IT DNA claims to help users confirm the relationship through more than 60 face point matches, only need to perform face recognition scans, and the matching accuracy rate is as high as 92%.
Of course, face recognition alone cannot achieve such a high level of accuracy, and it is likely to lead to the leakage of your sensitive personal information.
Some publicly available DNA databases have also been established. GEDMatch is a free-to-use DNA testing database, but after users uploaded their DNA files to sites such as GEDMatch for comparison, the relevant information was also obtained by the US police, and then a suspect user was arrested. This use of unreasonable means to obtain personal factor data has also triggered a large number of objections, requiring GEDMatch to restrict access to platform data.
Faced with the realities of these DNA phenotypes, biologist and engineer Yves Moreau argues that it's like a knife — people underestimate how sharp it can be.
When attacking criminals, it is also possible to cut ordinary people first.
Flaws are not hidden, essential
Since dna phenotypes still have many challenges and shortcomings, is there still a need for research? At least for now, as a new type of DNA technology, it is an unavoidable field for countries.
From a scientific point of view, studying the DNA phenotype can help all of humanity better understand who they are and understand the origin and evolution of human beings.
Although DNA does not accurately reflect the details of an individual's appearance, it is the most reliable proof of a person's biological and ethnic ancestry. Reading the hidden information in DNA enables you to understand migration trends, ethnic selection, and other random influences in human history.
For example, markers located on the Y chromosome can only be passed from father to son, and therefore fully reflect the geographical origin of the (male) ancestors in the paternal lineage.
With the help of a DNA phenotype testing system, individual ancestry can be roughly determined and certain externally visible features can be inferred based on geographic ancestry. People with blonde hair, blue eyes and light skin all have at least some European ancestry.
From a national perspective, many countries are also building their own biometric databases, which are regarded as an important part of digital governance. For example, India's Aadhar system, and the Australian government's facial recognition system "The Capability", can match the face in the surveillance video with the image information in the driver's license. In the future, combining DNA phenotypes to predict the perpetrator's face, it will no longer be difficult to quickly find potential suspects from the face database.
Establish a large-scale database with the characteristics of the national population, and become a soil for better application of technologies such as face recognition and deep learning. As some scientists have said, the more genetic data is identified, the more accurate the technique will be. In turn, it better reunites loved ones and brings criminals to justice earlier.
For individuals, today, face recognition technology has been applied to access control, security inspection, mobile payment, in and out of venues and many other occasions. Imagine a future world where a person's appearance can be accurately reconstructed from DNA alone, and id cards, passports, social security cards, etc. may no longer be needed. This will greatly improve the accuracy and uniqueness of face recognition scenes.
In addition, the relevant algorithmic model of DNA phenotype can also be extended to the connection between medical images (such as brain scans) and genes, providing assistance for medical diagnosis, genetic analysis, etc., to help study neurodegenerative diseases such as Alzheimer's.
Wherever we go, we leave some DNA behind. Let this information be seen, and perhaps those who are unknown will be able to have their own names. And the perpetrators of evil are also exposed to the sun.
This is the world of technology, so that everything is real and invisible.