Biology
“Life, uh…finds a way” — Malcolm, Jurassic Park
Thank you Malcolm. Life does indeed find a way.
The human body works in a way that is remarkably similar to a computer. It’s actually kind of scary. We’re pretty much robots already.
Computers deal with 0s and 1s, and humans deal with Ts, As, Gs, and Cs — the four nucleotides that make up our human genome. Each of us has a different genome (although 99.5% of it is the same in all of us), which makes us unique and is embedded within the nucleus of every cell of our body. It is essentially a long string of letters, organized as a double helix of base pairs of the 4 nucleotides adenine, guanine, cytosine, and thymine.
The Human Genome project mapped the entire human genome in the year 2000. From Wikipedia:
The Human Genome Project (HGP) was an international scientific research project with the goal of determining the sequence of nucleotide base pairs that make up human DNA, and of identifying and mapping all of the genes of the human genome from both a physical and a functional standpoint. It remains the world’s largest collaborative biological project. After the idea was picked up in 1984 by the US government when the planning started, the project formally launched in 1990 and was declared complete in 2000.
This was an absolutely transformational project that will have massive implications on medicine in ways that we are only just beginning to understand.
DNA has 3 billion base pairs.
Those 3 billion base pairs of our genome are organized into 23 chromosomes.
Each of our hereditary traits is found in a specific piece of the genome. Eye color for instance, is in the 15th chromosome. Most studies show the gene for balding is in the 20th chromosome, while hair color isn’t quite well understood — it’s believed 2 genes are involved.
The MCM6 gene is located on the 2nd chromosome and is responsible for lactose intolerance.
Humans have about 20,000 genes. You can actually see a list here, along with the most studied. Our continued understanding and mapping of disease, disorder, mutation and traits to specific genes continues to play an important role in our revolution in biology. Much like our modeling of atoms, elements and atomic particles has led to astounding innovations in all fields of science, our newfound systematic knowledge of the model of organisms will allow us to isolate and begin to figure out how to cure our most enigmatic diseases.
Now that we have mapped the genome there is a new effort called the Human Cell Atlas underway to map all 37 trillion cells of the human body.
Genome Kits
As costs have plummeted, there are now many at home kits you can use to get your entire genome sequences from a little bit of saliva. 23andMe is one of the leaders in this area, along with Ancenstry.com’s AncestryDNA which allows you to understand your heritage.
The Genetic Code
The creepy part of our genetics is the similarity between the operation of organisms and computers. Computers have opcodes (short bits of 1s and 0s) that designate certain operations, such as ‘Add’ or ‘And.’ In an organism, there are codons, which are formed of 3 base pairs and designate transcription into specific amino acids, which combine to create proteins that carry out functions in the body. This is the ‘genetic code’.
As Wikipedia states:
The genetic code is the set of rules by which information encoded within genetic material (DNA or mRNA sequences) is translated into proteins by living cells. Translation is accomplished by the ribosome, which links amino acids in an order specified by mRNA, using transfer RNA (tRNA) molecules to carry amino acids and to read the mRNA three nucleotides at a time.
Back to Jurassic Park, which can explain better than I ever could.
Epigenetics
A person’s genotype is their actual genome, while their phenotype is the expression of that genotype. Certain genes may be turned on or off based on certain environments.
In his fascinating book Inheritance, Sharon Moalem defines epigenetics:
“the study of how genetic traits can change and be changed within a single generation and even be passed down to the next as well”
He argues that our genetics are significantly more fluid and mutable than previously imagined. They aren’t ‘fixed,’ in other words. People with certain sets of genes can have wildly different reactions to different stimuli, whether it be childhood trauma or the intake of certain foods or drugs.
The Wired article, The End of Code, describes how we think about the mind and how we will eventually train computers rather than programming them. It examines the way in which our biology can be seen as a form of code:
Discoveries in the field of epigenetics suggest that genetic material is not in fact an immutable set of instructions but rather a dynamic set of switches that adjusts depending on the environment and experiences of its host. Our code does not exist separate from the physical world; it is deeply influenced and transmogrified by it. Venter may believe cells are DNA-software-driven machines, but epigeneticist Steve Cole suggests a different formulation: “A cell is a machine for turning experience into biology.”
Current State
The similarities between organisms and computers give scientists ideas about ways in which we can ‘hack’ biology.
“If I were a teenager today, I’d be hacking biology.” — Bill Gates
The implications of this are either frightening or exciting, depending on your perspective. They could save your child’s life, but also could lead to scary and weird genetic engineering.
CRISPR
DNA is simply a storage mechanism, just like your computer’s memory. In fact, scientists have now stored movies in DNA. Given DNA is basically just a data storage mechanism (and an extremely efficient one), there is no reason it can’t be edited given the right technologies.
Stands for “clustered regularly interspaced short palindromic repeats.
What It can Do
CRISPR places an entirely new kind of power into human hands. For the first time, scientists can quickly and precisely alter, delete, and rearrange the DNA of nearly any living organism, including us. In the past three years, the technology has transformed biology. Working with animal models, researchers in laboratories around the world have already used CRISPR to correct major genetic flaws, including the mutations responsible for muscular dystrophy, cystic fibrosis, and one form of hepatitis.
How it Works
A fantastic National Geographic article explains much of the process
The guide’s accuracy is uncanny; scientists can dispatch a synthetic replacement part to any location in a genome made of billions of nucleotides. When it reaches its destination, the Cas9 enzyme snips out the unwanted DNA sequence. To patch the break, the cell inserts the chain of nucleotides that has been delivered in the CRISPR package.
Implications
Given its ability to completely control/alter/delete diseases, disorders and malfunctions in our genetic code and any genetic code, CRISPR obviously has massive implications and scientists are a bit wary of its power. From National Geographic:
No scientific discovery of the past century holds more promise — or raises more troubling ethical questions. Most provocatively, if CRISPR were used to edit a human embryo’s germ line — cells that contain genetic material that can be inherited by the next generation — either to correct a genetic flaw or to enhance a desired trait, the change would then pass to that person’s children, and their children, in perpetuity. The full implications of changes that profound are difficult, if not impossible, to foresee.
And this is not only for humans, but for ALL biology. Hank Greely, director of Stanford’s Center for Law and the Biosciences explains:
With gene drives and CRISPR we now have a power over species of all kinds that we never thought possible.
A Crack in Creation: Gene Editing and the Unthinkable Power to Control Evolution
One of the first uses of CRISPR has been on mosquitos in order to destroy malaria. But as described in an excellent Wired article on CRISPR:
Crispr could spell the end of mosquitos-and malaria. But what about the bats that rely on mosquitos for food? Unintended consequences is a dangerous game.
This kind of genetic tinkering is reminiscent of the same type of electronic tinkering done by programmers in the 1970’s who used — but this is vastly different and far more powerful.
The more rapidly science propels humanity forward, the more frightening it seems. This has always been true. Do-it-yourself biology is already a reality; soon it will almost certainly be possible to experiment with a CRISPR kit in the same way that previous generations of garage-based tinkerers played with ham radios or rudimentary computers. It makes sense to be apprehensive about the prospect of amateurs using tools that can alter the fundamental genetics of plants and animals.
