Will Epigenetics Change the Speed of Evolution? | Cheryl Walker, PhD | TEDxBaylorCollegeofMedicine

Summary

This talk explores the stark contrast between the slow process of genetic evolution and the rapid changes in modern society, like technology and climate change. While evolution takes millions of years, our epigenome can respond quickly to environmental influences, even being passed down generations. The speaker highlights the potential dangers of environmental chemicals affecting our epigenome but also envisions a future where we can harness epigenetic knowledge to improve health, with advances in cancer therapies and nutrition. Now is the time to leverage this understanding and shape how we interact with our epigenome.

Takeaways

• 🐢 Evolution is a slow process, with human genomes changing less than 1% in two million years.
• 🚀 Modern technological changes, like the internet and AI, are happening much faster than genetic evolution.
• 🧬 The sequencing of the human genome in 2001 was a monumental achievement, taking over a decade and costing $300 million.
• 💰 Today, genome sequencing can be done in a few days for just $1,000, showcasing the rapid pace of technological progress.
• ⚡ Unlike slow genetic evolution, the epigenome can rapidly respond to environmental changes, affecting gene expression in real time.
• 🧑‍🔬 The epigenome is like software for the genome, telling cells how to behave depending on their environment.
• 🍽 Environmental factors, such as starvation or exposure to chemicals, can reprogram the epigenome, impacting development and health.
• 🔄 Epigenetic changes can be inherited, potentially affecting future generations based on environmental conditions experienced by ancestors.
• ⚠️ Some chemicals, like BPA, are known to reprogram the epigenome and may increase susceptibility to diseases like obesity.
• 🛠 Scientists are developing epigenetic therapies, harnessing the power of the epigenome to promote health and treat conditions like cancer.

Q & A

What is the process by which our genes change to give rise to new species?

Evolution is the process by which our genes change to give rise to new species. It is incredibly slow, with our genome changing by less than one percent in the two million years since we evolved from our ancestor, Homo erectus.

How does the pace of evolutionary change compare to the rapid changes we see in technology and society?

Evolution is moving at a glacial speed compared to the rapid pace of change we see in technology, artificial intelligence, climate, and social media. While we've gone to the moon and are planning to go to Mars, evolution is a much slower process.

What is the significance of the human genome being cloned and sequenced in 2001?

The cloning and sequencing of the human genome in 2001 was a miraculous achievement that was considered impossible at the time. It was published as an insert in Science magazine, marking an amazing moment in scientific history.

How has the cost and time required for genome sequencing changed since 2001?

The cost and time required for genome sequencing have drastically decreased since 2001. What once took over a decade and cost 300 million dollars can now be done for a thousand dollars in a few days.

What is the epigenome and how does it differ from the genome?

The epigenome is a series of small chemical modifications added either to the DNA or to the proteins that make up our chromosomes. It is built to respond rapidly to changes in our environment, unlike the genome, which changes very slowly over time.

How does the epigenome function in relation to the genome?

The epigenome functions as the 'software' of the genome, instructing the genome how to function. It determines which genes are turned on or off in different cells, thus giving cells their specific functions.

How does the epigenome respond to environmental conditions during development?

The epigenome can sense and respond to the environment during development. For example, a fetus developing during a time of starvation will develop differently than one with plenty of nutrients, as the epigenetic programming anticipates and prepares for the environment the child will be born into.

What are the potential negative effects of environmental chemicals on the epigenome?

Environmental chemicals, particularly those we are exposed to early in life, can reprogram our epigenome, potentially increasing our susceptibility to diseases like obesity. Chemicals such as bisphenol A (BPA) and lead are examples of obesogens that can cause these changes.

How can we harness the power of the epigenome to promote health?

We can harness the power of the epigenome by understanding and influencing its programming. We have discovered the enzymes responsible for epigenetic programming and are designing epigenetic therapies for diseases like cancer. Additionally, nutrients like folate can provide the epigenome with the materials it needs to function properly.

What is the potential of epigenetic therapies in medicine?

Epigenetic therapies have the potential to revolutionize medicine by targeting the epigenome rather than the genome itself. This could lead to treatments for conditions like cancer and other diseases influenced by epigenetic changes.

Why is it important to listen to what the environment is saying to our epigenome?

It is important to listen to what the environment is saying to our epigenome because environmental factors can significantly influence our health and susceptibility to diseases. Understanding these interactions can help us make changes to promote better health outcomes.

Outlines

00:00

🔬 Evolution vs. Modern Change

The speaker begins by contrasting the slow pace of evolution with the rapid technological and societal changes around us. Evolution, the process by which genes change to create new species, has caused less than 1% change in human genes over 2 million years. Meanwhile, humanity has experienced significant advancements like the internet, AI, and space exploration. This raises the question of whether remaining biologically unchanged in such a fast-evolving world is beneficial or harmful.

05:03

💻 Genome Sequencing and Its Rapid Progress

The speaker reflects on the monumental achievement of sequencing the human genome in 2001, a process that took over a decade and cost $300 million. Today, the same can be done for $1,000 in just days, showcasing an incredible acceleration in genetic technology. The speaker emphasizes the difference between this rapid change and the glacial pace of evolution, introducing the concept of the epigenome, which can rapidly adapt to environmental factors and is starting to be understood in ways that may allow us to control it for both good and bad outcomes.

10:04

🧬 Epigenetics: The Software of the Genome

The epigenome is described as the 'software' that tells the 'hardware' of our genome how to function. While every cell has the same DNA, the epigenetic programming varies by cell type, instructing each cell to express certain genes and not others. The speaker explains how this programming allows the body to adapt to environmental conditions, such as in the case of a fetus developing during starvation. These changes in the epigenome can even be inherited by future generations, showing both the adaptability and potential risks of this mechanism.

⚠️ Epigenetic Reprogramming and Environmental Dangers

The speaker highlights how chemicals in our environment can also influence the epigenome, sometimes in harmful ways. Exposure to chemicals, particularly early in life, can permanently reprogram the epigenome, increasing susceptibility to diseases like obesity. BPA and lead exposure are given as examples of chemicals that can cause epigenetic changes. The speaker contrasts how we can test chemicals for DNA mutations that cause cancer but lack tests for those that cause epigenetic mutations, despite their potential to be passed to future generations.

💡 Harnessing the Epigenome for Health

The speaker explores the potential of harnessing the epigenome to promote health and drive positive change. Recent advances have identified the enzymes responsible for epigenetic modifications, enabling the development of epigenetic therapies for diseases like cancer. Folate, a nutrient that prevents spinal cord defects, is highlighted as an example of how we can already influence the epigenome. The speaker concludes by urging society to take control of the epigenome to manage its response to environmental changes and improve health outcomes for future generations.

Keywords

💡Evolution

Evolution refers to the slow process by which genes change over time, leading to the emergence of new species. In the video, evolution is described as taking millions of years, such as the example of human evolution from Homo erectus with only a 1% change in our genome over 2 million years. The concept illustrates how biological changes are much slower compared to technological advancements.

💡Genome

A genome is the complete set of genes or genetic material in an organism. The video highlights the human genome, which was first sequenced in 2001 after a decade-long effort, costing 300 million dollars. Today, it can be sequenced in just a few days for a thousand dollars. This comparison showcases the contrast between biological evolution and rapid technological advancements.

💡Epigenome

The epigenome refers to a set of chemical modifications that sit 'on top' of the genome and regulate how genes are expressed. Unlike the slow pace of changes in the genome, the epigenome can respond rapidly to environmental factors. In the video, it is compared to software, while the genome is like hardware. The epigenome plays a key role in how organisms adapt quickly to changing environments.

💡Mutation

A mutation is a change in the DNA sequence that can result in altered genes. The video explains that mutations are rare and usually random, occurring in only a small percentage of people. For evolution to occur, beneficial mutations must be passed down to future generations. This slow and rare process is contrasted with the more adaptable nature of the epigenome.

💡Artificial Intelligence

Artificial intelligence (AI) refers to computer systems designed to perform tasks that typically require human intelligence. The video uses AI as an example of how technological advancements are happening at a much faster rate than biological evolution. The rapid growth of AI is a symbol of the dramatic pace of change in modern society compared to the slow evolutionary process.

💡Obesogens

Obesogens are chemicals in the environment that can disrupt the body's metabolism and increase susceptibility to obesity. In the video, obesogens like BPA (bisphenol A) are mentioned as examples of how environmental chemicals can reprogram the epigenome, leading to long-term health effects. The discussion highlights the epigenome’s ability to respond to environmental threats in ways that can be passed to future generations.

💡Epigenetic programming

Epigenetic programming refers to the way the epigenome modifies gene expression in response to environmental cues. The video explains that epigenetic programming allows cells in different tissues, such as liver and skin cells, to behave differently despite having the same DNA. This programming adapts to conditions like nutrient availability during fetal development, ensuring survival in challenging environments.

💡Environmental chemicals

Environmental chemicals are substances that people are exposed to in their surroundings, which can affect their health. The video mentions substances like BPA, lead, and other chemicals that can alter the epigenome, affecting not only individual health but also potentially being passed on to future generations. This illustrates the epigenome’s sensitivity to external environmental factors.

💡Epigenetic therapies

Epigenetic therapies are treatments designed to modify the epigenome in order to combat diseases. The video explains that by understanding the enzymes that control epigenetic changes, researchers are developing therapies, such as for cancer, which target the epigenome. This represents a future where we can intentionally influence gene expression to improve health.

💡Human genome sequencing

Human genome sequencing is the process of determining the complete DNA sequence of a human's genetic material. In the video, the speaker reflects on the monumental achievement of sequencing the human genome in 2001, which took over a decade and was published as a special insert in Science Magazine. This milestone is compared to modern advances that make genome sequencing faster and cheaper.

Highlights

Evolution is an incredibly slow process, with the human genome changing by less than 1% in 2 million years.

In contrast to evolutionary change, technological advances such as the internet, AI, and space exploration are happening at warp speed.

In 2001, the human genome was fully sequenced, a project that took over a decade and cost $300 million.

Today, the human genome can be sequenced for $1,000 in just a few days, showing the dramatic pace of technological progress.

Our epigenome, unlike the genome, can respond rapidly to environmental changes, affecting our health and adaptation in ways we are just beginning to understand.

Mutations in DNA are rare, random, and only matter for evolution if they occur in germ cells and provide a survival advantage.

The epigenome acts as the software of the genome, determining which genes are activated in specific cells, like liver or skin cells.

The epigenome can be influenced by the environment, including chemicals like BPA, which can reprogram it and potentially cause health issues like obesity.

Epigenetic changes, unlike genetic mutations, can be inherited by subsequent generations, affecting long-term health outcomes.

Certain chemicals in the environment, called obesogens, can alter epigenetic programming and increase the risk of obesity later in life.

There are well-established tests for chemicals that can mutate DNA and potentially cause cancer, but we lack similar tests for epigenetic mutations.

Researchers are now exploring the potential to harness the epigenome to promote health, such as developing epigenetic therapies for cancer.

Epigenetic therapies and dietary interventions like folate supplementation are examples of how we can influence our epigenome for health benefits.

Scientists have identified the enzymes responsible for epigenetic programming, known as the 'readers,' 'writers,' and 'erasers' of epigenetic software.

The epigenome allows for rapid adaptation to environmental changes, and we are beginning to unlock its potential to intentionally improve health outcomes.

Transcripts

[Music]

has anyone seen evolution around here

no of course not

a lifetime would not be long enough to

observe evolution which is the process

by which our genes change to give rise

to new species

and it is incredibly slow

for example in the two million years

since we evolved from our ancestor homo

erectus

our genome has changed by less than one

percent

in 2

million years

now compare that to the pace of change

occurring all around us in our everyday

lives the internet artificial

intelligence our climate

social media we've gone to the moon and

back and mars is next

and so while change is happening all

around us at warp speed

and evolution is moving at glacial speed

will we remain the same

would that be a good thing

a bad thing

here's an example

it's 2001

and we have just

cloned and sequenced the human genome

it was

miraculous some had said at the time it

couldn't even be done

but the human genome was now sequenced

and it was actually published as an

insert in science magazine

it was an amazing moment i remember

taking that insert home

laying it out on the floor of the living

room and calling my children over and

saying you have to look at this this is

amazing touch this

this is the sequence for the human

genome

that effort took over a decade

cost 300 million dollars

and today

for a thousand dollars in a few days you

can have your genome sequenced

this is a pace of change that has no

meaning

in evolutionary terms

but we have a second driver for change

our epi genome which can actually

respond rapidly to the environment

around us

and it's changing us today in ways we

are just beginning to understand

for both good and bad

and soon we will be able to control it

so why is evolution so slow

changing genes is hard

and so for example the first step in

changing a gene would be to acquire a

mutation

and these mutations are generally random

and rare and they may only occur in one

in a million people and even then only

after it has escaped all of the

mechanisms we have in place

just to protect our dna

from the environment and from these

types of mutations

and of the 30 trillion cells in our body

only the germ cells the ones who could

pass that mutation on to the next

generation

would count

so a mutation in a skin cell would do

evolution no good

and if that mutation occurs in a sperm

or an egg cell and if it gets passed to

the next generation it has to be a

beneficial mutation and has to provide a

survival advantage so that then it can

increase in the population and now give

evolutionary drive

so is it any wonder that evolution is

very much akin to the million monkeys on

a million typewriters that could

eventually write shakespeare

but in contrast to this slow process for

evolution of our genes

our epigenome is actually built to just

to respond rapidly

to changes in our environment

so the epi genome it actually means on

top of the genome and the epigenome is a

series of small chemical modifications

that have been added either to the dna

or to the proteins that make up our

chromosomes

and like the genes themselves this epi

genome is also inherited from one

generation to the next

now

a good analogy for understanding the

relationship between our epigene on our

genome is a computer

so the genes that we get from mom and

dad are very much like the hardware in

your computer when you've bought your pc

you have a pc or you've bought a mac and

now you have an apple product

the epi genome is like the software on

that computer the epi genome is the

software of the genome and it tells the

genome how to function

so while every cell in your body has the

exact same dna

the epigenetic software in cells are

different

so for example the epigenetic software

in a liver cell

will tell that cell to turn on liver

genes and don't turn on muscle genes and

turn on the enzymes you're going to need

to make glucose

the epigenetic software in a skin cell

will say well don't turn on those liver

jeans but turn on those keratin genes so

you can make that protective layer that

we need for the skin

and so it is this epigenetic programming

that makes the genome work

and just like your computer would be a

very expensive paperweight without its

software

so the genome cannot function without

the epigenome

and another difference between the

epigenome and the genome is that the

epigenome is built to sense and respond

to the environment

here's an example

a fetus that is developing during a time

of starvation will develop very

differently than one that is developing

during times when there are plenty of

nutrients because the epigenetic

programming is actually sensing the

environment

and reprogramming that individual in

preparation for the tough times ahead

the epigenetic software of the liver

will be different and cause the liver to

make glucose differently the muscle mass

will be different the pancreas will make

insulin differently all of this

epigenetic reprogramming is in

anticipation so that when that child is

born

they will have a survival advantage in

this starvation environment

and what we are learning is that this

epigenetic reprogramming that can occur

as an adaptation to our environment can

actually then be inherited by subsequent

generations

now this ability to adapt and help us

survive

however

is a double-edged sword

because not only can the epi genome

sense and respond to our natural

environment

but it can also sense and respond to

chemicals in our environment

in fact we are learning today that many

of the chemicals that we are exposed to

particularly early in life

may be reprogramming our epigenome

in ways that we then carry with us for

the rest of our life

and increase our susceptibility to

disease

an example is obesity

and so we are learning now that there

are many chemicals in our environment

that if we are exposed to them early in

life in fact these chemicals as a group

are often called obesogens because of

the way they change the epigenetic

programming

change our metabolism and then increase

our susceptibility to obesity later in

life

you may even know the names of some of

these some of you may have heard of

bisphenol a or bpa

and we're working very hard to remove

this from plastics and consumer products

you may have seen labels on your water

bottles bpa free

bpa is an example of a chemical in our

environment that we know can reprogram

our epigenome in this way

in fact you can look at infants who have

been exposed to lead

and their neonatal blood spots have an

epi genome that is different

and can actually predict which of those

infants are going to go on to become

obese later in life

another difference between

mutations of genes

and changes of our epigenome which are

themselves sometimes referred to as epi

mutations

is that we have tests that are often

able to tell us which chemicals are

dangerous

and we want to keep them out of our

environment

decades ago we realized there was a

linkage between the ability of a

chemical to cause a mutation in dna and

the ability of that chemical to cause

cancer and this linkage between the

ability to mutate dna and cause cancer

is so strong that we have many tests

today that we can use to screen

chemicals before we allow them into our

environment so that we can keep those

chemicals out that can induce mutations

that can potentially cause cancer

unfortunately we don't have a test like

that for chemicals that can cause epi

mutations and we know that these epi

mutations

like the mutations and genes themselves

can also be inherited from generation to

generation

but what if we could harness the power

of this epigenetic software and use it

to drive change that could promote

health what if we could

talk intentionally to our epigenome and

influence its power over our genome

in fact today we are poised to do just

that we have now discovered the enzymes

in cells who are responsible for doing

this epigenetic programming we know who

the readers the writers and the erasers

of this epigenetic software

are

and in fact today we have unraveled the

epigenetic software for over a hundred

different

cell types

and we have taken our first steps to

using this knowledge

we are designing today epigenetic

therapies for cancer

we know that when we put folate in our

diet to help prevent

spinal cord defects like spina bifida

that that folate is actually providing

the raw materials that our epi genome

needs to do its work

so

while our genes are remaining the same

and change is accelerating at a pace we

could only have imagined

our epigenome is able to respond to that

change and we have the power to control

it

now is the time for us to harness the

power of the epigenome and use it to our

advantage

now is the time for us to listen to what

the environment is saying to our

epigenome

and maybe even change the conversation

thank you

[Applause]