Translator: Michele Gianella Reviewer: SILVIA ALLONE
Some 10.000 years ago, humans invented agriculture.
Plant and animal species were domesticated in specific areas of the world.
The Fertile Crescent was
one of the most important domestication centres
of plants - we heard about wheat - and livestock species.
Domestic animal and plants have thereafter colonised the planet,
along with the expansion of agriculture,
human migrations and conquests.
And they have settled in agro-climatic areas
much unlike the domestication centre.
Several millennia of natural selection have adapted domestic species
to a range of diversified conditions:
extreme climate,
different pathogens, different soils, different feed sources.
This process has fostered animal and plant adaptation
to produce under diversified conditions.
For example this Moroccan goat,
a goat domesticated in Taurus mountains, in Anatolia,
has adapted to live in the much hotter Morocco
and feed, when there's no vegetation,
on the Argan tree fruits.
By the way, it also helps spreading the seeds of this tree.
These “genetic solutions”
discovered throughout millennia by natural selection,
are a heritage of local breeds.
Unfortunately, local breeds
are at risk of extinction, we are loosing them.
In 2015 FAO estimated
one third of all the planet's genetic and animal resources,
of all livestock breeds,
is under threat of extinction.
And we know nothing for another third.
And these resources are a valuable source of adaptation
for agriculture in general.
Natural selection
has been integrated, from domestication on,
with the man-made one,
At first in order to tame behaviour,
and later for the sake of efficiency.
After the Industrial Revolution,
human ability to select superior genotypes
increased significantly,
thanks to the adoption of sophisticated scientific approaches.
This has progressively led
to the development of what we define intensive agriculture:
intensive livestocks, and industrial cultivation of plants.
On one hand, we all know, these systems have a serious environmental impact.
They use energy, deep ploughing, pesticides, fertilizers,
drugs in the livestock,
and a high livestock density
that, when not properly managed, may negatively impact animals' health.
On the other hand, they increased yield a lot:
milk production quadrupled,
and corn yield increased a staggering ten-fold,
in just one century.
They responded to some social dynamics:
after the Industrial Revolution,
human population increased exponentially,
moved from the countryside to cities
and people started asking for more abundant, safer and cheaper food.
The result, the industry's response, was industrial agriculture.
A second step forward, on productivity is very recent,
fostered by the DNA revolution.
In the last 10-12 years, 20 years,
our ability in reading the DNA,
that is the genetic code of plants, animals and humans,
has speed up exponentially:
consider that if the speed in 1980
could be compared to a snail moving at one meter per hour -
so a rather slow speed even for a snail -
today we move as fast as a supersonic jet
flying at several thousand kilometres per hour.
Likewise, DNA analysis has gotten a lot cheaper:
from one billion dollars in 2001, to sequence the first human genome,
to less than 1.000 dollars today.
This allowed us to greatly increase
the level of resolution of DNA analysis
and consequently, the understanding of its biology.
As comparison, we may say
that we have switched from low resolution, a few pixels,
as you see in this portrait that seemingly hides Mona Lisa,
to a much higher resolution.
This also made us realize when we were making mistakes, of course.
(Laughter).
[Level of resolution in DNA analysis]
Indeed, DNA analysis
has allowed to increase the selection efficiency.
Increasing the selection efficiency -
dairy bulls are a good example for that:
dairy bulls do not produce milk,
so their genetic assessment, up until five years ago,
was related to the production of their daughters.
But their daughters only make milk when a calf is born.
So, long story short,
a bull was evaluated only when grand-sire [grand-father],
Then and only then, it could be chosen as an improved bull,
worth to spread gametes across the population, or discarded.
Genomics, that is DNA analysis,
allows now to evaluate a calf at birth.
We no longer need to wait for daughters' production:
we immediately know, looking at his DNA,
if the bull's genetic value will be high enough
or it is to be discarded.
This has accelerated by three times
the selection speed in the dairy cattle field.
The same technologies are fostering the same process in plants.
As a result, the selection speed has increased.
Why speed is now more and more important?
It is important because some ongoing processes
are progressing very rapidly.
First process:
human population's exponential growth, there will be 10 billions of us in 2050.
FAO estimated a need
of 70% more food in 2050, to feed the world.
This is a problem,
as agriculture can count
on 1,5 billion hectares on the planet.
And this number can’t significantly increased.
We could exploit some areas now considered suboptimal,
but certainly we can’t cut forests.
What should we do?
Firstly, we certainly have to reduce waste,
from field to fork.
However, that is not enough.
We must increase the production efficiency
on these available hectares.
Second problem: global warming.
Carbon dioxide is steadily increasing,
it has been exponentially growing since the Industrial Revolution,
as a result of human activities.
Agriculture contributes to this trend,
and while estimates of this contribution vary a lot -
they're marginal according to farmers, or very relevant according to industries,
it's anyway somewhere between nine and 25 percent,
with at least half the impact
due to animal farming alone.
And in particular,
to the methane emitted by ruminants.
Methane is a powerful greenhouse gas.
Anyway,
whatever the contribution of agriculture to carbon dioxide production is,
this is to be surely reduced.
We need to reduce this impact
while increase productivity.
That's a challenge!
Why should we reduce CO2 emissions?
Because the planet's average temperature is increasing.
It is increasing:
NASA scientists estimate
it increased about one degree Celsius in the last century.
A very rapid increase,
and this is why I previously stressed the need to act quickly.
For those who do not trust NASA data,
here is clear, spot-on evidence of global warming.
We're all waiting for the next step.
(Laughter).
So, will there be a food crisis?
Will we be quick enough to increase yield and decrease pollution?
Both issues are urgent.
Well, research is exploring new technologies.
One of these
is called genome editing.
It is a new technology that, much like in a word processor,
can cut a DNA letter and paste a different one.
Sometimes, replacing or erasing a single letter
can profoundly alter
a plant or animal trait.
In this case, for example,
erasing a single letter in rice
makes it resistant to a disease known as rice-blast,
which is usually treated with pesticides with a high environmental impact.
This mutation is naturally present in some varieties.
What editing does, essentially,
is copying those genetic solutions
that were found by natural selection
and conserved in local breeds, varieties.
It simply copy-paste them into more productive varieties.
The same goes for bovine polledness.
Some breeds are polled [hornless].
Polledness is a favourable trait
for both humans, farmers who work in close contact with cattle,
and the cattle themself, as they can hurt one another
while trying to establish a hierarchy in the herd.
Also in this case, the mutation
has been copied from local breeds and pasted in highly productive ones.
Another piece of news is that last year
mouse stem cells have been differentiated into in-vitro sperm cells.
For us males,
it's a punch in the gut,
Why?
Because if we take a female embryo,
and differentiate its sperm cells
it will only generate females,
and males will no longer be needed.
So I put myself in the shoes of poor male mice.
In any case, let’s say
that if we connect these technologies -
genomics,
reproductive biotechnologies
and editing, that is copying from local breeds -
while genomics alone can speed up selection by three-folds,
with all these systems together we can take the whole process in the lab,
moving the selection from the field into the lab,
and we could speed up selection
from 3X to 30X.
This means we could make in five years
as much progress as in the last 150 years.
This, I’d like to say,
on the one side could also allow
to select very difficult traits:
those related to environmental adaptation;
Those decreasing environmental impact.
Think about it:
plants that resist diseases;
that can grow on very salty soils;
that tolerate water scarcity.
They might even have a higher efficiency, especially in photosynthesis.
Therefore they would capture more CO2 from the atmosphere
mitigating the environmental impacts.
Likewise, animals could also get more resistant to diseases
and therefore would reduce drug consumption;
that have a lower impact,
meaning cattle producing less methane,
which is useless for them and harmful for the environment.
As a scientist, I must say
that before integrating and applying all these technologies together
we still have to break a number of technical barriers.
However, looking back,
many such barriers have been quickly broken,
over the last five - ten years.
We may therefore be fast enough
to reach this difficult goal
of increasing food production,
while lowering its footprint on the environment.
However, as these technologies are hi-tech and very powerful,
a debate is needed between science and society.
Our duty, as scientists,
is to inform, look for solutions
and provide information to open a debate
as thoughtful as possible, without polarization.
In order to understand how and when to use and regulate these technologies.
In the meantime,
we must preserve livestock and crop biodiversity,
because those solutions we might be able to copy in the near future
will be critical for us and even more so for future generations.
Thank you.
(Applause)