Imagine being able to change something about yourself, not just your hairstyle, but at the very core of your being—your genes. For the first time in history, humans have the tools to modify and select genetic traits. This is a groundbreaking development, as no one has ever played this game before.
Life on Earth, from the simplest organisms to the most complex, has been shaped by two key principles: mutation and selection. According to the rules of evolution, changes in an organism’s genetic code happen randomly, not because the organism needs them. The traits that get passed on are determined by natural processes. However, humans are now rewriting these rules, taking control of our evolutionary path.
Humans have drastically changed our environment, reducing the likelihood of dying from natural causes. Predators and other threats are less of a concern, and science has advanced to the point where it can repair our bodies and protect us from invisible dangers. Today, more people suffer from overconsumption than from scarcity.
For thousands of years, we have been selecting beneficial traits in plants and animals, deciding which traits are passed on. This control over selection has significantly increased human life expectancy. But this only allows us to guide evolution. Once we discovered DNA, the molecule that governs these traits, we realized we could accelerate evolution.
DNA is composed of long chains of nucleotides, and natural mutations occur infrequently and randomly. In the mid-20th century, scientists found ways to speed up mutations using radiation or chemicals, but the results were unpredictable. Contrary to popular belief, this process does not lead to superhuman abilities. In the 1970s, scientists began swapping entire segments of DNA between species, creating insulin-producing microbes, virus-resistant plants, and even mice with human genes. They could control what was being edited, but not where in the genome the new DNA was inserted.
Scientists needed a precise tool to make a single change in 3 billion DNA bases, and in 2012, they developed CRISPR. Despite its cereal-like name, CRISPR has the potential to reshape humanity by combining unnatural selection with targeted mutations. Evolution could be in our hands.
CRISPR was discovered in bacteria, one of life’s simplest organisms. Like humans, bacteria face constant threats from viruses. If a microbe survives an infection, it retains some viral DNA in a part of its genome known as clustered regularly-interspaced short palindromic repeats, or CRISPR. This serves as a memory of past infections to protect it and its descendants. Scientists realized that CRISPR could be applied to any type of cell, allowing precise genome editing.
CRISPR gives us the ability to edit genomes like a word processor. When cells repair cut DNA, they can rejoin the ends, often removing a letter or two and disrupting the genetic code. Alternatively, the cell can use another template to incorporate new DNA, allowing us to splice in new genes with accuracy. Genes can be turned on or off, and infections like HIV can be eliminated. Many human diseases are caused by mutations in single genes, and CRISPR could potentially reverse these. Even complex traits like height or heart disease, influenced by multiple genes and environmental factors, might be within reach.
To modify every cell in a body, human genetic modification must occur at the earliest stages of embryonic development, and those changes would be inherited by future generations. This raises important ethical questions: if CRISPR is used in embryos to enhance traits, would we also use it to influence behavior? Could parents request specific genetic changes for their child? While curing diseases and creating designer babies may seem similar, they differ significantly in ethical considerations.
Beyond curing diseases, CRISPR prompts us to confront challenging questions. Who decides what constitutes a “better” baby? What if only affluent individuals can afford genetic editing? Should parents have the authority to determine their child’s genetic future? Perhaps they already do, through birth control and techniques like in vitro fertilization.
We find ourselves at a new evolutionary crossroads. On one side is nature, with natural selection and random mutation shaping a diverse array of species. On the other side is humanity, equipped with tools that could rival or surpass the speed and power of evolution as we know it. It’s clear that the ability to control mutations and selection in humans is no longer a question of whether we can, but whether we will.
Stay curious. If you want to learn more about CRISPR and the intriguing future it may bring, check out the documentary “Mutant Menu” by Vanessa from BrainCraft. It delves deeper into many of the topics we discussed today.
This article is part of a special series about the story of our species. Explore our origins, connections, and relationships in other articles, and stay tuned for more insights into our fascinating journey.
Engage in a structured debate about the ethical implications of genetic editing. Divide into two groups: one supporting the use of CRISPR for human enhancement and the other opposing it. Prepare arguments and counterarguments, considering aspects like accessibility, societal impact, and moral concerns.
Participate in a hands-on simulation where you use a CRISPR model to “edit” a fictional organism’s genome. This activity will help you understand the precision and complexity involved in genetic editing. Discuss the potential outcomes and challenges of each edit.
Research a real-world application of CRISPR technology, such as its use in agriculture, medicine, or environmental science. Prepare a presentation to share your findings with the class, highlighting both the benefits and potential risks associated with the technology.
Write a short story or essay imagining a future where genetic editing is commonplace. Consider how society, ethics, and daily life might change. Share your work with the class and discuss the different perspectives and scenarios envisioned by your peers.
Conduct an interview with a local scientist or researcher who works with genetic editing or related fields. Prepare questions about their work, the potential of CRISPR, and their views on its ethical implications. Share the insights gained with your classmates.
Sure! Here’s a sanitized version of the transcript:
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[MUSIC] Is there something you’d change about yourself? Not just your hairstyle, but down at the genetic level? For the first time in human history, the ability to build and select genetic traits is within reach. The challenge is that no one’s played this game before. [music]
Mutation and selection. These two principles have shaped all life on Earth, from simple organisms to complex ones. Evolution’s rule book states that changes to life’s instructions happen randomly, not because an organism needs something, while the selection of traits that are passed on is determined by natural processes. However, humans are rewriting these rules in remarkable ways, taking charge of our evolution.
For starters, we’ve significantly altered our environment, making it much harder to die from natural causes. Today, there’s a minimal chance of being harmed by predators or other humans, and science can repair our bodies or protect us from unseen threats. More people today suffer from overconsumption than from scarcity.
For thousands of years, we’ve been selecting which plant and animal traits are beneficial, determining which are passed on and which are not. This increased control over selection has led to a doubling of human life expectancy in just a few generations. But this only allows us to guide evolution. Once we discovered the molecule that governs these traits, we realized we could accelerate evolution.
DNA’s information is encoded in long chains of nucleotides, and natural mutations occur infrequently and randomly. In the mid-20th century, scientists found ways to speed up mutations using radiation or chemicals, but the outcomes were still unpredictable. Contrary to popular belief, this process does not lead to superhuman abilities. Later, in the 1970s, scientists began exchanging entire segments of DNA between species, creating microbes that produce insulin, plants resistant to viruses, and even mice with human genes. They could control what was being edited, but not where in the genome the new DNA was inserted.
What scientists needed was a precise tool capable of making a single change in 3 billion DNA bases, and affordable enough for widespread use. In 2012, they developed CRISPR. While it may sound like a breakfast cereal, CRISPR has the potential to reshape humanity, combining unnatural selection with targeted mutations. Evolution could be in our hands.
CRISPR was discovered in one of life’s simplest organisms. Like humans, bacteria are constantly under threat from viruses. While we can afford to lose some cells to fight an infection, a single-celled microbe cannot. If a microbe survives an infection, it retains some viral DNA in a part of its genome known as clustered regularly-interspaced short palindromic repeats, which is where CRISPR gets its name. This serves as a memory of past infections to protect it and its descendants. Those viral sequences are copied into RNA and loaded into a special protein called Cas9. If the virus infects again, and CRISPR recognizes it, the Cas9 protein cuts the viral DNA.
Scientists realized that CRISPR could be applied to any type of cell, and by reprogramming the target, CRISPR could cut any genetic sequence with precision. This gives us the ability to edit genomes like a word processor. When cells repair cut DNA, they can rejoin the ends, often removing a letter or two and disrupting the genetic code. Alternatively, the cell can use another template to incorporate new DNA, allowing us to splice in new genes with accuracy. Genes can be turned on or off, and infections like HIV can be eliminated. Many human diseases are caused by mutations in single genes, and CRISPR could potentially reverse these. Even complex traits like height or heart disease, influenced by multiple genes and environmental factors, might be within reach.
However, to modify every cell in a body, human genetic modification must occur at the earliest stages of embryonic development, and those changes would be inherited by future generations. This raises important questions: if CRISPR is used in embryos to enhance traits, would we also use it to influence behavior? Using CRISPR, if parents desired a baby with specific traits, could they request changes to certain genes? While curing diseases and creating designer babies may seem similar, they differ significantly in ethical considerations.
Beyond curing diseases, CRISPR prompts us to confront challenging questions. Who decides what constitutes a “better” baby? What if only affluent individuals can afford genetic editing? Should parents have the authority to determine their child’s genetic future? Perhaps they already do, through birth control and techniques like in vitro fertilization.
We find ourselves at a new evolutionary crossroads. On one side is nature, with natural selection and random mutation shaping a diverse array of species. On the other side is humanity, equipped with tools that could rival or surpass the speed and power of evolution as we know it. It’s clear that the ability to control mutations and selection in humans is no longer a question of whether we can, but whether we will.
Stay curious. If you want to learn more about CRISPR and the intriguing future it may bring, our friend Vanessa from BrainCraft has produced a documentary titled “Mutant Menu.” Head over to BrainCraft to watch it now; it delves deeper into many of the topics we discussed today.
This video is part of a special series about the story of our species. In other videos, we explored our origins, our connections, and our relationships. If you haven’t already, check out the rest of the series, and be sure to subscribe so you don’t miss any of our future videos.
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This version removes any informal language and maintains a professional tone while preserving the core content.
Genetic – Relating to genes or heredity, often involving the study of how traits are passed from parents to offspring. – Genetic research has advanced our understanding of inherited diseases and their potential treatments.
Editing – The process of making changes to the genetic material of an organism, often to correct or enhance certain traits. – Scientists are exploring genetic editing techniques to potentially eliminate hereditary disorders.
Evolution – The process by which different kinds of living organisms develop and diversify from earlier forms during the history of the earth. – The theory of evolution explains how species adapt to their environments over time through natural selection.
Mutation – A change in the DNA sequence of a gene, which can lead to variations in traits and sometimes result in genetic disorders. – A mutation in the gene responsible for hemoglobin can lead to sickle cell anemia.
Selection – The process by which certain traits become more common in a population due to advantages they confer in survival and reproduction. – Natural selection favors traits that enhance an organism’s ability to survive and reproduce in its environment.
Crisper – A technology used for precise editing of genes, allowing scientists to alter DNA sequences and modify gene function. – CRISPR technology has revolutionized genetic research by enabling targeted gene editing with high accuracy.
Traits – Characteristics or features of an organism that are inherited from its parents, such as eye color or leaf shape. – The study of genetics helps us understand how certain traits are passed down through generations.
Embryos – Early stages of development in multicellular organisms, following fertilization and before becoming a fetus. – Researchers study embryos to understand developmental processes and the impact of genetic mutations.
Ethics – The branch of knowledge that deals with moral principles, especially as they apply to scientific research and practices. – Ethical considerations are crucial when conducting experiments involving human embryos and genetic editing.
Diseases – Disorders or conditions that affect the normal functioning of an organism, often caused by genetic mutations, pathogens, or environmental factors. – Understanding the genetic basis of diseases can lead to more effective treatments and preventive measures.
