
Using DNA to Sketch What Victims Look Like - avenoir
https://www.nytimes.com/2017/10/19/nyregion/dna-phenotyping-new-york-police.html
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spaceflunky
Let's get to the heart of what this is: a crude pseudoscience.

While DNA call tell you a few obvious traits, like sex and ancestry with high
confidence, almost everything else is speculative (i.e. they are LIKELY to
have such and such other traits, but in reality they may not have any of those
traits at all).

This is 21st century phrenology.

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epmaybe
You know what would be interesting, though probably also flawed? Looking at
mRNA.

The reason DNA wouldn't work that well is because a lot of DNA we have isn't
actually coded into the traits we present. I think this is what happens at a
fairly abstract level:

DNA -> RNA(whole) -> Splicing out of non coding (introns?) portions of the RNA
-> RNA(coding) -> some more pre-processing -> mRNA -> Proteins

Those proteins are most likely what help us look the way we do. So going a
step back, mRNA could be an interesting target for understanding what genes
are actually on and coding how we look.

An obvious flaw from the get go: mRNA is extremely difficult to extract from
human tissue. Yields are super low in laboratories, and is consistently an
issue in molecular biology research. And you'd have to design a primer to
amplify the amount you obtain, that matches up with every strand of mRNA
necessary to get a good idea of what someone would look like. Not to mention
there's probably some step I'm missing in this process that would affect the
role of mRNA. Something like microRNAs, maybe?

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mosselman
Why don't we get some side-by-sides between renders and real photos of people?

~~~
avenoir
Here is an article [1] about someone who confessed of murder after his DNA
sketch was released. It looks fairly close, but far from a match.

[1] [https://nypost.com/2017/11/17/man-confesses-to-murder-
after-...](https://nypost.com/2017/11/17/man-confesses-to-murder-after-dna-
based-model-released/)

~~~
mikestew
That’s interesting, because the perp must have been looking for reasons that
it looks like him, and found them, whereas I ask “look like anybody know?
Nope.” even if the kid lived next door. If he’d just kept his mouth shut...

Of course, I’ve always questioned police artist sketches, too. Almost all of
them look like every/none white/Black/Hispanic man/woman I’ve ever known.
There might be similarities to someone I know, but not enough that I’d have
SWAT kicking down their door.

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uptown
For those interested in this subject, check out the work of Heather Dewey-
Hagborg:

[http://deweyhagborg.com/](http://deweyhagborg.com/)

[https://www.smithsonianmag.com/science-nature/creepy-or-
cool...](https://www.smithsonianmag.com/science-nature/creepy-or-cool-
portraits-derived-from-the-dna-in-hair-and-gum-found-in-public-
places-50266864/)

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agitator
It looks like this is based algorithmically on genetic ancestry. I'd like to
see a deep learning model trained from facial image and genetic data to build
a tool for generating faces from genes. Anyone know if something like this is
feasible? Is it possible to extract only genetic data that has an impact on
facial appearance? Or is this something that we still don't know much about?

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m3kw9
Maybe somebody is already using deep learning to train DNA with faces. Not
sure how the architecture would look like but I think some form of
unsupervised learning to find features mixed with GAN.

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iamwil
I guess this is more of a guidance and visualization technique. Presumably,
you can also use it to sketch what perpetrators look like.

