Resurrecting A Dead Idea
    As a Science educator, I get asked a bunch of interesting questions by students.  Many of them are about standard topics like explosions, space or quantum zeno effects during antimatter hadron collisions.  The usual.  But by far the most common things I get quizzed about are dreams and death. 
    Dreams are a tricky one to answer because nobody has a clue what's going on there, so most of the time I have to answer such questions with a shrug.  Death, on the other hand, is a really interesting topic and well worth exploring because we actually do have some good knowledge about what happens.  Especially the issue kids always want to know about: "could a zombie apocalypse really happen?"  It's a question we've all asked ourselves at some point, often while watching the shopping channel, and I addressed it briefly in an article I wrote a while back (here ya go kids).
    In that article I focused on what would happen to our infrastructre during such a crisis and how we would survive.  Short answer: move to Scandanavia (actually that solves a lot of problems).  But at the end of the article I dismissed the whole thing as fanciful because it was basically impossible for zombies to exist.  Once you're dead, you're dead. 
    However, part of being a Scientist is changing your mind when the evidence requires it, and I am happy to say that on the issue of zombification I may need to do just that.  Research I've slowly become aware of has made me re-evaluate the whole question and I have come to the conclusion that if you are prepared to be a little generous in your definition of "zombie" then they aren't totally ridiculous.
    Which is just as well.  The US Department of Health commissioned a report in 2011 on how the CDC might prevent a zombie apocalypse in a paper called ‘The CDC Zombie Initiative’.  Originally published as a tongue-in-cheek way of exploring the idea of mass panic, they quickly had to issue a public retraction and apology when people assumed they were proposing a real zombie-outbreak was imminent...ironically causing a mass panic.  Now, thanks to this blog, a zombie apocalypse might really be on the cards after all.  Hurrah for Science!

The Biology of Death
    At a cellular level, death is a simple process.  A cell is a bag of chemical reactions so it’s easy to pinpoint when it has died because the reactions change irreversibly, usually accompanied by the outer membrane dissolving and everything leaking out.  Once a cell has expired there is no going back, but at the scale of a whole organism it’s harder to define when death occurs because everything shuts down at different rates.
    We’ve all heard stories of people who were apparently declared dead by a doctor, only to return to life after a brief intermission.  They sound like urban legends but it’s actually a recognised medical phenomenon called Lazarus syndrome.  Since 1982, when it was first defined, nearly 40 people have been declared dead by a qualified physician but then decided to make a comeback.  The most extreme case being that of 78-year-old Walter Williams from Mississipi, who was registered dead in February of 2014...only to be discovered a few days later by coroners trying to kick his way out of a body bag.  Alive and kicking indeed.
    Because different organ systems shut-down at different times it can occasionally happen that the main systems go offline, giving the appearance of death, but there can be plenty of chemistry still going on and if the right reactions occur, the whole system can reboot.  There are several animals which do precisely that during hibernation after all, including extreme examples like the Alaskan wood fog, Rana Sylvatica, which can survive with two-thirds of its blood frozen solid during winter, before thawing itself back out. 
    Cells which have truly died can’t be brought back, but new cells can always be regrown (you do it every time you recover from a cold) so it’s possible for parts of an organism to shut down but then rebuild.  In fact, according to one research paper published in 2017 by Peter Noble, some cells actually increase their productivity after the body is dead, so even a corpse is still alive in many ways.  Death is not clear-cut and can, in some rare cases, be reversed.
    We can definitely agree however, that a body eventually reaches a point of no return, even if we can’t say precisely when this point occurs.  People have returned from year-long comas but nobody has returned from something like rigor mortis (when the body stiffens up because you are no longer making ATP, the chemical required to break down bridges between muscle fibres).  If something fully dies, it’s not possible to bring it back because the cells have burst, but we might be able to justify a zombie apocalypse by picking the right biochemistry to make a person appear to die.

Horrors in the Night
    Most people have a fear of death so it’s no surprise that zombies are a common staple of horror stories.  Zombies represent the inevitability of death slowly creeping toward us without pause, breaking through our barricades to consume us no matter what we do. 
    The modern depiction of zombies as shambling corpses seeking the living to eat them alive comes almost entirely from the 1968 movie Night of the Living Dead by George Romero, in which a group of middle-class Pennsylvanians get trapped in a country house under siege by re-animated corpses, originally referred to in the script as "ghouls".    
    Over the course of six films, Romero invented most of the familiar rules we know today for zombie stories e.g. being bitten will turn you into one, zombies can’t be stopped unless you destroy their brain and they gradually get more rotten as their flesh decays. 
    Prior to Romero’s hexology of films, zombies were already a well-known monster in folklore but they were just corpses who came back to life, often with their brains in tact.  Some of them even ran for government.  The Bible itself refers to mass outbreaks of zombies stumbling from their graves and tormenting the living (Zechariah 14:12, Matthew 27:52) as shown in the Fresco below from Notre Dame de Bayeuax Cathedral.
    In Romero’s series, it is hinted that the outbreak is caused by a space probe detonating in the atmosphere and showering the ground with radioactive debris.  Radioactive material can certainly do icky things to you like make your skin fall off, but it can’t make you impervious to pain and turn you into a cannibal.  If we want to legitamise the zombie outbreak we'll have to look somewhere other than 1960s cold war paranoia-infused science fiction...which is always a disappointing sentence.

Taste the Rainbow
    The word ‘zombie’ comes from the Haitan word zombi (originally Central-West African) and the folkore of Haiti features tales of people brought back from the dead in a trance to do the bidding of the witch who summoned them.
    In 1985 the ethno-botanist Wade Davis even wrote a book about the science of Haitan zombification called The Serpent and the Rainbow, which was adapted into a semi-decent horror movie directed by Wes Craven and starring, of all people, Bill Pullman...whose only other horror credit is freaking Casper. 
    In The Serpent and the Rainbow, Davis analysed the powder being used by Haitan witches to zombify people and found it to contain a chemical called tetrodotoxin - the active ingredient in puffer-fish poison.  Davis claimed this dust would send a victim into a comatose state for a few hours, giving the appearance of death, before they would rise in a hypnotic trance, ready to do the bidding of the witch master.
    His results were resoundingly panned by other scientists who tried to repeat the findings but couldn’t because his methodology was so poor.  Furthermore, when the powder was analysed by other teams they found it didn’t contain enough tetrodotoxin to even make someone sick, let alone knock them into a coma or put them in a trance (which is not a known tetrodotoxin side-effect anyway).  
    To give you some idea of how lousy the science in the book is, Davis claims that a witch only had to sprinkle zombi-dust on the road in front of their intended victim to achieve the effect.  It sounds like the whole thing had more to do with the power of belief than the power of witches.
    If you are raised in a culture that believes ardently in zombification at the hands of a witches, it’s conceivable you might go along with it because of something called ‘the nocebo effect’ - a reverse placebo where you can be convinced you have an illness you don’t really have.
    Stranger things have happened.  Take the case of Sam Shoeman who was diagnosed with cancer in 1973 and died on schedule according to doctor predictions.  It was only at his autopsy that it was discovered his doctors had made a mistake and the tumour was benign.  He showed all the appropriate symptoms of slowly dying of cancer, despite not actually having it!  Apparently, you can literally talk someone to death.  Something I will have to remember for my classes.
    Nobody knows how placebos or nocebos work, but our minds are evidently capable of doing things to our bodies through willpower alone.  It seems likely to me that so called "witches" are simply telling people they have to act like zombis and the victims just go along with the ritual because they believe they have no choice.  So I don’t think we can trigger a genuine zombie apocalypse using puffer-fish.  Sorry.  Puffer-fish are useless.

What about that guy on the news..
    So you may have heard about 'bath salts’ (if you haven't, your kids will have), it's the street drug which hit headlines in 2012 because it reportedly turned people into violent flesh-eaters.  Just to make sure we're handling rumour control here, there's no such thing.  It's a twisted account of a real event which happened once and once only.  This gets a little weird though.
    On May 26th 2012, in Miami, a man named Rudy Eugene decided for some reason to attack a homeless man named Ronald Poppo and...eat his face.  While holding a Bible.  Naked.  For eighteen minutes.  
Eugene only stopped after being shot five times by a police officer and when he turned out to be a proud Haitan, it was no surprise the press jumped on the story and dubbed him The Miami Zombie.
    Police at the time described his relentless and delusional behaviour as consistent with someone taking ‘bath salts’ (a mixture of mephodrone and dimethocaine) and hence bath salts became unofficially known as the ‘zombie drug’ because it made you impervious to pain and  susceptible to cannibalism. 
    However, the toxicology screening of Eugene’s corpse didn’t find any trace of bath salts, only large amounts of cannabis (and large amounts of Ronald Poppo I guess).  So I don’t think street drugs are going to give us the zombie apocalypse we’re looking for.  I think if we want to come up with a plausible zombie pandemic, it’s going to have to come from the world of infectious diseases.

Plague-rism
        In the Danny Boyle movie 28 Days Later, the outbreak is started by an engineered super-virus which amplifies the aggression centre of the amygdalae and turns the host into a maniac.  Although technically the monsters in 28 Days Later aren’t true zombies because they don’t die and come back, they just go nuts.  They also run and zombies are supposed to represent the inevitable onslaught of creeping mortality...we can’t have them being zoom-bies.
    I'm going to totally steal their idea however, because it seems to me that it would be the best way of doing it.  What we're looking for is some sort of infection which can cause a person to apparently die, before coming back to life as an indestructable flesh-eater on a shulking, rotting rampage.
    To start with, there are plenty of diseases which can affect a creature's brain, sometimes in very surprising ways.  Consider ophiocordyceps, a breed of fungus which has a disturbing effect on carpenter ants.  Once the ants breathe in the spores, it somehow alters their neural chemistry and forces them to abandon whatever they are doing and climb the nearest plant, after which the fungus blasts through their skull, releasing more spores to rain down on the ants below.  
    This is a parasite which makes its host no longer care about their own safety or other members of their species.  It just makes them climb no matter what, forcing them to their own head-exploding doom.  If we could propose a comparable fungus for humans that would give us a start.  Some sort of fungus which infects the brain and makes the host not care about pain or the well-being of other people.  There is no known fungus at present which does this (probably a good thing) but baring in mind we haven't explored something like 90% of our own rainforests, fingers crossed such a human-brain fungus could be out there.
    The next thing to study I reckon is lyssavirus, the viral infection which causes rabies.  Rabies can be transferred through the bite of an infected host and has an eerily familiar effect on its victims.  The symptoms present slightly differently depending on the person, but it usually causes paralysis and apparent death-like symptoms in the early stages, before heightened aggression and violence a few days later.  
    Thinking about it, perhaps that’s where the original zombie myth came from?  The word zombi does originate in Central-West Africa where rabies is common, so maybe that’s where we got the first stories of people who apparently die, then come back and attack us?  Zombie myths could be the result of rabies.   Rabies doesn’t easily transfer from human to human though, so we’d be talking about an unknown strain which can transfer rapidly, moving to anyone who gets bitten.  
    If we combine this hypothetical rabies virus with our hypothetical brain-controlling fungus then we might be onto something at last.  Contracting a fungal and viral infection simultaneously is pretty rare, although there is one known species of mycovirus (a virus which infects a fungus) which can be transferred to humans called AfuTmV-1.  Clearly it’s possible for a fungal infection to hitch a ride with a virus molecule, so let’s say that’s what our zombie pathogen consists of. 
    Now all we need to do is throw in an aggressive bacteria which can cause necrotising fasciitis - a disease in which the soft tissue of your skin starts rotting while you’re alive, making the infected parts of your body look corpse-like, the so called "flesh eating bacteria" (do NOT google that before a meal).  There are quite a few bacteria which do this so let’s propose a variety which spreads in the saliva.

Why I went into Science
    So, let’s say that by sheer bad-luck, there is a double epidemic unleashed on the Earth by the powers of fate.  A rabies/fungal infection hits first, making all the victims appear dead for a few days before they rise to perpetrate attacks on the living (caused by the rabies).  The fungus simultaneously switches off their sense of self-preservation (as it does in ants), meaning infected people will stop at nothing to get food, ignoring all injuries...unless we deactivate their ability to move by destroying the brain.
    Then, gosh-darn it, an outbreak of flesh-eating bacteria just happens to hit us as well.  All the infected people whose immune systems have been weakened by the rabies-fungus cocktail now end up catching this bacterial inconvenience, making their skin decay as they go after the living.  Voila.  Zombie-apocalypse achieved.  Also, probably the only blog on the internet to feature Disney and Bible references alongisde Motorhead and cannibalism!
    I'll be right back, there's some guy in a CDC jacket at my door...

Image Credits
Thumbs up Zombie: TheLastStand
CDC poster: CDC
Motorhead: Flashwounds
Reusrrection Fresco: Biblent
Puffer-fish: cornell1801
Actual bath salt: greeneyedgrace
Bambi: YouTube

Privilege
    This has been one of the trickiest blogs I have ever written.  Race is a delicate issue and I'm writing as a white, English-speaking male.  In other words, I'm writing from a position of privilege without having been on the receiving end of racial abuse.  I have not suffered the oppression and discrimination people of colour regularly endure and I would not pretend otherwise.  I am also not an expert on Biology, so to write an article on the Biology of race has been a huge challenge.
    I would like to start by expressing enormous gratitude to my friend Lee Agostini, a genetic researcher at Thomas Jefferson University who consulted on the Biology, and also offered insights into the experience of being a black man in modern America.  You should absolutely follow him on instagram: @lee_the_scientist and check out his awesome Science-themed website: BioIsLifeMedia.
    The important thing to say up front is that we all agree racism is bad (unless you're a racist I guess?) but when issues of race get discussed there are misconceptions and cultural confusions which make the debate appear not so black and white, if you'll excuse the pun.  My aim in this article is to highlight the hyporcisy of racism from a scientific point of view because as far as Science is concerned racism makes no...freaking...sense!
    However I'm fully aware that as a white non-Biologist I may have missed crucial nuances of the discussion.  Please contact me if I'm getting stuff wrong (I want to learn) but also please appreciate that if I say something you find offensive it's coming from a place of accidental ignorance, not wilfull malice.  If I upset you, I pre-emptively cry your pardon and ask you to help me do better!

The Strange Case of the Black Woman Who Wasn't
    I want to kick things off by reviewing one of the most bizarre media firestorms I have ever seen.  You may recall hearing about Rachel Dolezal on the news but if not, here’s a quick summary:  Rachel Dolezal was elected the Spokane chapter president of the National Association for the Advancement of Coloured People in 2014.  She taught classes on African-American culture at Eastern Washington University and served on the Police Ombudsman Commission for Spokane, representing the black community.  Dolezal was a well-respected public figure who spoke out on black issues...until a year after her election when a member of the press exposed something remarkable.  Dolezal was not really black.  She was white.
    To be clear, there’s no reason a white person shouldn’t be working for the NAACP - that wasn’t the issue.  The issue was that she had been claiming to be something she wasn’t.  She was committing fraud.
    She doesn’t exactly deny these allegations either.  In one interview with NBC, a reporter asked her “Do you feel you’ve been deceptive at all?” to which Dolezal responded: “There have been some moments with a level of creative non-fiction,” which I think is a fancy way of saying “yes, I was lying,” although she insists she never intended to deceive anyone.  Her skin is kinda dark for a white person (see below) but when she claimed her parents were black, that was flat-out creative non-fiction.
    When Dolezal’s story was inevitably brought into the media glare it sparked an international debate about her mindset.  To some, she was highlighting issues of race and identity, to some she was a con-artist wanting attention and to others she was a mentally-troubled woman desperately seeking identity.
    Dolezal has written a book about her experiences - In Full Colour - and there is a documentary about her on Netflix called The Rachel Divide charting her life after the chaos.  What fascinates me most as a scientist however, isn’t her motivation, it's her terminology.  Dolezal has described herself as transracial, transblack and even explained that she “identifies as black”.  What exactly is she talking about?

LGBT…Black???
    Using the phrase “I identify as black” has obvious parallels with the vernacular of the transgender community.  I’ve written in great detail (here) about the biological difference between male and female brains and how transgender people are not ”making it up” or “wanting to be something they’re not” (quite the opposite…they’re wanting to be something they are).  I won’t rehash that whole essay, I'll just say that the biological evidence comes down firmly in support of transgender people.  But the language we use is very important.
    If a transgender woman says “I am a woman,” then critics could fire back by saying “No you’re not.  You don’t have a uterus or XX chromosomes,” which would technically be correct.   But if a transgender woman said “I want to be a woman,” that wouldn’t be accurate either.  A transgender woman doesn’t simply like the idea of being female, her neural architecture means she is female.  
    That’s why the phrase “I identify as a woman” is so useful.  It is stronger than saying “I want to be female,” but doesn’t make a false claim about biological anatomy which gives ammunition to critics.  So when Dolezal “identifies as black” we have to question what she means.  She seems to be saying that being black is an inherent thing and that she is (to put it crudely) a black woman in a white woman's body.  So, fully aware of the potential minefield involved, I’m going to do my best to explore what Biology says about "race".

It’s In Your Genes
    Every nucleus in your body contains a set of DNA strands collectively called your genome.  It’s split into chunks called genes which are bits of biological information telling your body what to be.  Genes code for things like eye colour, tongue length, heritable diseases etc. and although it’s not as simple as "one gene = one feature", the basic principle is more or less that.  
    The percentage of genes which actually makes us different to each other is very small (we're more alike than we are different) but within that small percentage, there's a huge amount of diversity accounting for variety among the human population.
    Different versions of a gene are called alleles and because our species has been spreading across the planet for a very long time, adapting to different environments, this has led to certain alleles cropping up in some regions more than others. 
    We can measure the probability of a particular allele occurring with what’s called the allele frequency - how often an allele appears within a group of people.  For instance, 25% of people in Central Asia have B-type blood whereas in Northern America it’s closer to 5%.  That means if you test the DNA of an unknown individual and find it contains genes for B-type blood, it’s more likely they are from Central Asia, but you can't say for certain.  B-type blood appears all over the world and obviously 75% of Central Asian people do not have it, so it wouldn’t be accurate to say Central Asian people have B-type blood.  Just slightly more likely.  
    The same is true with diseases.  Sickle-cell anemia is more common in Afro-Carribean people and cystic fibrosis is more common among Europeans, but white people still get sickle-cell anemia and black people still get cystic fibrosis.  Certain groups may have a higher allele frequency overall, but on an individual basis you can’t tell anything about a person’s geographical region from their genome.
    So when a person says they are something like “50% Irish” this is biologically meaningless.  There is no such thing as an Irish gene, just allele frequencies which may be higher on average in the Irish population as a whole.  You can't be half of one race and half of another.  Unless you exist in the Star Trek episode Let That Be Your Last Battlefield (TOS Season 3 Episode 15)...

Skin-Deep?
    Obviously there isn't one country where black people come from, but there is an obvious biological difference between people of different skin colour...they look different!  Black and white people's genes are obviously causing differences in appearance, so doesn't that mean there is a genetic difference between black and white people after all?   
    Well, technically yes.  There are several genes which work together to define skin colour but the primary one is called MC1R and I'm going to use that as a shorthand for the whole collection.  MC1R alleles tell your skin what colour to be, so yes black and white people do have different versions of one particular gene.  But that is the only difference.  MC1R doesn't code for anything else about the person, not even hair or eye colour.
    The colour of your skin is unrelated to the rest of your genome and that’s crucially important.  You can genetically determine (with reasonable accuracy) if a person is black or white by looking at their MC1R, but that’s all the gene tells you.  There is no other physiological or neurological feature black people have that white people don’t or vice versa.  Two black people (people with the same MC1R allele) can otherwise have totally different genomes while a white and black person (people with different MC1R alleles) can otherwise be genetically identical.
    You can’t be white on the surface but internally black because “internally black” doesn’t mean anything.  Your black or white characteristic is exclusively external and unrelated to everything else about your body.  Black people's brains are no different to white people's brains so I'm afraid the word "trans-racial" is not an actual thing as far as Biology is concerned.
    Besides, skin colour is a spectrum.  Everyone has melanin in their skin (including white people) and there is no cutoff between someone being black and someone being white.  It would be like defining a mountain as being split into the summit and base, or defining a rainbow’s colours as either red or violet.  There's a lot of stuff in between the extremes. 
    Our brains work by putting things in categories because it’s easier to store information.  But “ease of classification” probably shouldn’t be our priority when we’re dealing with actual human beings.
    I mean, if we absolutely have to split people into categories then why stop at skin-colour?  Shouldn't we start seeing redheads as a different “race” to blondes and brunettes?  Or blue-eyed people as a different race to brown-eyed people?  There's the same amount of genetic difference between them as between black and white. 
    So as far as Biology goes, there really is no such thing as race.  People have different colours on their surface but that is as far as the difference goes.  It’s almost like people of different colour…are all equal?????  How about that.

What about DNA testing?
    You’ve probably seen adverts for DNA-testing kits.  These are products which take a sample of your DNA (usually from a cheek swab) which you send off for analysis and get a profile back.  They can tell you things like eye colour, shape of your ear-lobes or even ear-wax consistency. 
    The problem comes when people claim they can determine your ancestry from your DNA i.e. saying things like: you are 20% European, 50% scandanavian, 6% hispanic etc.  I’m not going to outright say these companies are misleading anyone (I don't want to get sued) but they don’t seem to be going out of their way to correct certain misconceptions about genetics.
    The first problem is that genome analysis is looking at allele frequency so everything is based on probability not certainty.  The second flaw is that the precision of DNA testing is not as good as CSI might have you believe.  Not even close.
    In one disturbing 2010 study conducted by Itiel Dror, 17 DNA specialists were given a sample of DNA used in a criminal trial and asked to compare it to the defendant.  One specialist concluded the defendant was guilty, four said it was inconclusive and twelve said the defendant was innocent.  Depending on which laboratory the court hired to consult with, the trial could have gone in very different directions…and these are specialists hired by our legal system.
    One DNA-testing company I looked at claimed an ancestral gene precision of +/- 30%.  That means any percentage they give you is falling within a range 60 percentage-points wide!  Suppose you get your results and it says you're 40% South American.  The precision is 30% either way which means you could actually be anywhere from 10% to 70%.  Really it’s not much better than guessing.
    The third big flaw with ancestral DNA testing is that their allele databases are drawn from modern populations.  Nobody has an allele library for cavemen because not many cavemen were voluntarily giving blood.  So if your profile says you're 70% Indian, that doesn't mean 70% of your ancestors come from India.  It means your genome is similar to 70% of the modern Indian populace.  So unless they were going back in time and becoming your ancestors, it's very misleading to say your genetic commonality with modern people can be "traced back" to ancestors.
    It's also important to remember that genetics doesn't work like blending paints together.  It's not as if you are a 50% hybrid of mom and dad.  DNA sequences get mixed up in chunks so although you have genes from both your parents they can be rearranged in a novel way which neither of them has. 
    There’s also the pretty important point that you are a mutant.  The average human genome contains over 400 mutations; features not found in either of your parents or any of your ancestors.  The further back you go, the more mutations you have to factor in and eventually you get to a point where a lot of your ancestors become undetectable! 
    So even if there were racial genes they would fade from the genome after a few rounds of breeding.  And besides, we couldn't trace your nationality back more than about 18-19 generations because prior to that, countries didn't exist.

Black Is A State of Mind?
    It’s possible that when Rachel Dolezal says she identifies as black she means culturally.  It would make more sense (not hard to do, since Biologically it makes no sense) although it’s still a pretty nebulous thing to say since there are numerous cultures of people around the world whose members have black skin and saying they are all the same is a bit…well…kinda racist.
    There’s a vast difference between the culture of the Masaai tribes of Kenya and the aboriginal people of Australia.  There’s an even bigger difference between the cultures of Detroit Michigan (80% black) and people living in the Republic of Congo.  In Nigeria, where I grew up, there are intense tribal rivalries and members of such tribes would be sickened at the suggestion they share a culture with their rivals just because they have the same colour skin. 
    There is no such thing as one "black culture," because there's huge cultural diversity among the billions of black people on Earth, just as there is between all the white people.  Saying you identify with black culture is like saying you identify as "religious”…it’s a sweeping statement with little specificity.  Which one do you mean? 
    Besides, if you appreciate certain cultural ideologies which are more common among black populations, you can still appreciate them as a white person.  If race is a social construct (as Dolezal has claimed often enough) surely identifying as black is buying into that same social construct?  Why not just be a white person who admires the culture of a particular group of black people? 

The Aftermath
    A lot of members of the NAACP were understandably outraged by Rachel Dolezal's actions because the discussion suddenly shifted away from how black people are treated in society to…what is going on with this woman?  It made everything a media circus and nobody was listening to what really mattered anymore.
    I suppose the only thing you could argue all black people have in common is the centuries of suffering they and their families have endured at the hands of white people.  Countless black people experience racism (both overt or passive).  Some would even say that experiencing racism is a critical aspect of the African American experience, and this is not something Dolezal has lived through.  Her great-great grandparents were not slaves.  She did not go to school with children who called her the N-word at recess.  She has not had to put up with constant harmful stereotypes since birth and she does not fear for her life when she gets pulled over.    
    If Dolezal wants to admire and champion a particular community then good for her.  But when she claims to be black it doesn't mean anything biologically and its only cultural meaning involves things she has not experienced.
    Ultimately, people have different coloured skin and that’s all there is to say.  You country of birth doesn’t affect your genetics and you can’t learn a person’s racial origin based on DNA.  Skin colour has no more to do with a person's brain than does their eye colour.  Race does not exist, but sadly racism does.  And it's not just ethically awful, it's sloppy Science.

Image Credits
Racist brains: Rice
Privilege Sign: Cincinnati
Rachel Dolezal: BBC
Star Trek: Wikia
Black child with blue eyes: Afritorial
Mixing paint: Winduprocketapps
Old Map: FineartAmerica