Why Don't We All Have Cancer?
Summary
TLDRThe script explores the natural and inevitable process of cell death and renewal in the human body, highlighting the millions of cells that die and are replaced daily. It delves into DNA replication, the potential for mutations leading to cancer, and the body's autocorrect mechanisms that catch most errors. The video also discusses environmental factors contributing to DNA damage and the surprising rarity of cancer given the numerous daily mistakes. Advances in science and technology are presented as our接力 to natural selection in the ongoing battle against diseases like cancer, with a focus on prevention, detection, and treatment improvements.
Takeaways
- 💀 The human body constantly sheds dead cells, with about 5.5 grams of dead skin lost weekly.
- 🌪️ Indoors, a significant portion of the material seen dancing in sunlight is actually dead human skin.
- 🔥 Humans are biological furnaces, converting food energy into movement, breath, thought, and warmth.
- 🤲 The heat from a resting hand is sufficient to power a Stirling engine, demonstrating the body's active cellular processes.
- 🧬 Human DNA replication involves copying three billion nucleotides, a process prone to errors, some of which can be harmful.
- 🧬 DNA mutations can be random, inherited, or environmentally induced, such as by UV radiation.
- 🦒 Giraffes have black tongues due to dark pigmentation that protects against solar radiation.
- 🛡️ The body has biological mechanisms like proofreading and mismatch repair that correct most DNA errors.
- 💊 Despite these mechanisms, cancers still develop due to the accumulation of mutations over time.
- 🧬 Cancer is not a single disease but a collection of 200 different diseases, each with unique characteristics.
- 🌱 Natural selection has less influence on diseases that affect us later in life, as it is more concerned with reproductive success.
- 📈 Modern advancements in science and technology are improving our ability to prevent and control cancer beyond our body's natural defenses.
- 🌐 The Large Hadron Collider's technology has contributed to medical advancements, such as reducing the need for special shields during eye tumor removal.
- 🛑 The fight against cancer is not just a battle but a mutiny, where we are now in control of the direction our 'boats' take.
Q & A
How many cells die in a human body since the beginning of the video?
-More than a million cells have died in the human body since the beginning of the video.
What percentage of the material seen indoors, dancing across sunbeams, is dead human skin according to Ohio State University?
-According to Ohio State University, 80% of the material seen indoors, dancing across sunbeams, is dead human skin.
How much dead skin does an average person shed off their body every week?
-An average person sheds about 5.5 grams of dead skin off their body every week.
What is the biological process that allows the heat from a person's hand to run a Stirling engine?
-The biological process that allows the heat from a person's hand to run a Stirling engine is the body acting as a biological furnace, burning food energy to move, breathe, think, and stay warm.
How many mistakes are made during the synthesis of DNA for each daughter cell during cell division?
-During the synthesis of DNA for each daughter cell during cell division, enzymes make 120,000 mistakes.
What is the term used to describe a cell that behaves abnormally, stimulates its own growth, and can potentially multiply forever?
-A cell that behaves abnormally, stimulates its own growth, and can potentially multiply forever is referred to as cancer.
What are some of the causes of DNA mutations in the human body?
-DNA mutations in the human body can occur randomly, be inherited, or be caused by the environment, such as exposure to ultraviolet radiation from the Sun.
Why do giraffes have black tongues?
-Giraffes have black tongues because the dark pigmentation protects their tongues from solar radiation while they are hanging out all day.
What is the term used to describe the phenomenon where natural selection has less influence on diseases that affect us later in life?
-The term used to describe the phenomenon where natural selection has less influence on diseases that affect us later in life is the 'selection shadow'.
How has modern science, technology, engineering, and mathematics contributed to the fight against cancer?
-Modern science, technology, engineering, and mathematics have contributed to the fight against cancer by making progress against late-acting diseases, improving prevention, detection, and treatment methods, and increasing survival rates.
What has been the historical improvement in the survival rate of people diagnosed with cancer over the past 40 years, according to Cancer Research UK?
-According to Cancer Research UK, 40 years ago, only one in four people lived ten years or longer after being diagnosed with cancer. Today that number is 2 in 4, and they believe that in twenty years, the statistic could be as high as 3 in 4.
Outlines
🧬 The Human Body: A Dance of Life and Death
This paragraph delves into the natural process of cellular death and renewal in the human body. It highlights how our bodies are constantly shedding dead skin cells, contributing to the dust in our environment. The video also touches on the living aspect of our bodies, emphasizing the role of cellular activity and division, which is crucial for our survival. The process of DNA replication is discussed, noting the potential for errors that can lead to mutations, some of which may result in cancer. The paragraph introduces the concept of diseases like cancer, which are characterized by abnormal cell growth, and how environmental factors like UV radiation can contribute to genetic damage.
🦇 The Evolutionary Puzzle of Aging and Cancer
The second paragraph explores the evolutionary concept of the 'selection shadow' and its implications for the prevalence of diseases like cancer in humans. It contrasts the lifespans of mice and bats to illustrate how different environmental pressures can influence the development of age-related diseases. The paragraph also discusses historical life expectancies and how advances in modern medicine and technology have increased human lifespans. It emphasizes the progress made in cancer research and prevention, highlighting the importance of continued efforts to understand and combat this complex group of diseases. The video concludes with a metaphorical reflection on the battle against cancer, suggesting that it is less of a war and more of a collective effort to overcome a mutiny within our own bodies.
Mindmap
Keywords
💡Cell Division
💡DNA
💡Mutation
💡Cancer
💡Autocorrect
💡Natural Selection
💡Selection Shadow
💡Life Expectancy
💡Environmental Damage
💡Genetic Variation
💡Cancer Research
Highlights
Every week, about 5.5 grams of dead skin sheds off of your body.
80% of the material seen indoors, like dancing dust, is dead human skin.
The human body is a biological furnace, converting food into energy for various functions.
The heat from a resting hand can power a Stirling engine, as demonstrated on Grand-Illusions[.com].
Cells divide millions of times a day, with DNA replication requiring the copying of three billion nucleotides.
During cell division, enzymes make 120,000 mistakes, some of which can be harmful or beneficial.
DNA mutations can lead to abnormal cell behavior, potentially resulting in cancer.
Cancer is a term for 200 diseases with various origins and natures but similar abnormal cell growth characteristics.
DNA mutations occur randomly but can also be influenced by environmental factors like UV radiation.
Giraffes have black tongues due to dark pigmentation that protects against solar radiation.
Our bodies have biological mechanisms that correct over 99% of DNA errors, similar to autocorrect on a phone.
Cancer development is influenced by the accumulation of mistakes and mutations over time.
Cancer Research UK has contributed significantly to understanding and combating cancer.
Evidence of the selection shadow suggests that diseases affecting complex multicellular organisms late in life persist.
Humans are living longer today due to advancements in science, technology, and medicine.
40 years ago, only 1 in 4 people lived ten years or longer after a cancer diagnosis; today it's 2 in 4.
Modern advancements like proton beam control from the Large Hadron Collider have improved cancer treatment.
Cancer is not one disease but 200 different types, requiring various cures and prevention methods.
The fight against cancer is a relay race where natural selection has done some work, and now it's humanity's turn.
Transcripts
Hey, Vsauce. Michael here.
Since this video began
more than a million of your cells have
died. It's natural, don't worry.
But you are literally covered with death
Dead stuff. Fingernails, your hair,
the outermost layer of your skin - all made out of dead things.
And you are losing this dead stuff constantly. Every week
about 5.5 grams of dead skin sheds off of your body.
Ohio State University found that 80%
of that material you see indoors, beautifully dancing across sunbeams,
is dead human skin.
But for the most part, you are made out of
living stuff. You are a biological
furnace, burning food energy to move and breathe and
think and stay warm. As you can see on Grand-Illusions[.com], the heat from your own
hand while you sit still
is enough to run a Stirling engine.
Your cells are busy and active and dividing
millions and millions of times every day. In fact, because of that, you shouldn't even
really be called a person.
You should be called a persON
and on and on and on and on and on and on and on... But here's the really
mind-blowing
thing about the mind sustaining process of cell division,
the replication of instructions. DNA for each daughter cell
requires copying an exact sequence
of three billion nucleotides. That's a lot.
Luckily, our bodies are perfect-ly happy to do it but they're not perfect.
Every time a single cell in your body divides, the enzymes that synthesize
your DNA
make 120,000 mistakes.
Some of these mistakes
wind up being beneficial. Some of these mistakes wind up being harmful and
some are just neutral,
they don't make a difference. But if a mistake,
a mutation in a cell's DNA, causes the cell to behave abnormally
and stimulate its own growth, ignore signals to stop,
stimulate the body to give it its own blood supply, potentially
multiply forever and unstick from where it began to spread throughout the body,
it becomes a special type of cell.
We have found 200 diseases with various origins and natures that
fit this description. Despite being different, they often go by the same name:
cancer.
DNA mutations occur randomly in your body
but they can also be inherited or caused by the environment.
For example, exposure to ultraviolet radiation from the Sun
can cause all kinds of damage, including genetic damage.
If little or no skin protection is used, the accumulation of all these types of damage
can be quite dramatic. This man drove a truck
for years, exposing one side of his face to more sunlight
than the other.
And for 15 years this woman worked in a room
that had the same window. A window to her left.
Environmental damage to the body,
whether cancer-causing or not, is serious business.
In fact, giraffes have black tongues because the dark pigmentation protects
their tongues
from solar radiation while they're hanging out all day.
Go back far enough, beyond where sunshine hits, and their tongues are pink.
Given the sheer number of environmental dangers to our DNA
and the sheer number of mistakes our own bodies make with our DNA every day,
it is incredible that we all aren't developing cancers constantly
and immediately after being born. One of the things we have to thank
is our body's own version of autocorrect.
Biological mechanisms, like proofreading and mismatch repair,
catch and correct or stop more than 99% of errors.
We grow old and pass away for many,
many reasons. But when it comes to cancers, our bodies'
own internal autocorrect is like the autocorrect
on your phone. It's pretty good, but it's not perfect. Cancers
still develop, especially after the accumulation of mistakes and mutations
over time. I'm incredibly grateful to Cancer Research UK.
They helped me a lot with this episode, and thanks to work by groups like them,
we are at an accelerating rate finding ways to prevent and control cancer
beyond what our bodies can do alone. I mean, after all, natural selection can
only see so much
because of the selection shadow.
We aren't all the same and if your genetic variations make you and your children
more successful at reproducing,
well, what do you know, your characteristics become more common.
But this phenomenon has a weak influence
here. Later in life, after your role in reproduction and raising offspring to
independence
has passed.
We have found evidence of the selection shadow
at work with mice and bats.
Raised under perfect conditions, with veterinary medicine and safe lives,
mice only live about two to three years.
Whereas bats, with similar sizes and metabolisms, can live for
thirty years or more. The significant difference here is that
unlike mice, bats have had in the wild for millions of years
fewer predators - a smaller chance of dying early
due to extrinsic mortality. They've, on average, had more days for natural selection
to influence. This could be a very good explanation for why diseases that affect
our complex multicellular selves
late in life are still with us.
But wait, why are humans living so long today?
I mean, in the past, but genetically recently, weren't
teenagers considered middle aged?
Not really. Well, it's true that in the past life expectancies were quite
a bit lower, a life expectancy is merely an
average number of years a person was expected to live as soon as they were born.
And in the past, infant mortality was so high
the average was brought down significantly. It's true that in the
early 1600s, here
in England, life expectancy was only 35 years.
But if you made the age of 21... Well,
you could easily expect to live well into your 60s.
Lifespans that go beyond the age of reproduction have
always made sense for humans, because we are intelligent
and social, useful to one another and our children
take a lot of time and guidance to gain independence.
But that just moves the selection shadow ahead. It's still there,
suggesting that, in the end, our bodies might just be
tools our sex cells use to reproduce
and grow up to do it again. Nature and time haven't helped our bodies battle
late acting diseases because a chicken
is just an egg's way of making another egg.
But maybe not for long. Our minds and modern science technology engineering
and mathematics are making progress
against late acting diseases. And when it comes to cancers,
Cancer Research UK points out that 40 years ago
only one in four people lived ten years or longer
after being diagnosed. Today that number is 2 in 4.
And they believe that in only twenty years that statistic could be as high as 3 in 4.
Refrigeration and sanitation are tackling stomach cancers caused by infection,
vaccines are preventing cervical cancer, anti-smoking campaigns and reductions
of obesity and diabetes and the elimination
of cancer-causing chemicals from our everyday lives are giving us an edge.
We learn more every single day. The process
is slow, but steady. Because cancer is not just
one thing. It's unlikely there will ever be a single cure for cancer because
there are two hundred different types
of cancers. But there will be cures and better methods of prevention
and detection. Advances are coming from all over.
For example, what we have learned about controlling proton beams because of the
Large Hadron Collider
has reduced the need for special shields during the removal of eye tumours.
The statistical surprise that cancers aren't more common in our bodies
is a sign that we're involved in a relay race.
Natural selection already did some of the work, now it's our turn.
When we talk about cancer we often use the language of war:
it's a battle, it's a fight. But the challenge
isn't so much a war with winners and losers and surrender
as it is a mutiny. We can't help the fact that we are all at sea.
Natural selection at least gave us boats
but now we are making where those boats go
our decision.
And as always,
thanks for watching.
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