Hello, my name is Chris Kempes.

I'm a physical biologist and professor
at the Santa Fe Institute.

And welcome to this course on the Origins
of Life.

How life originated is one of the most
interesting, complicated,

difficult, and still open questions in 
modern science.

And throughout this course, we're gonna
introduce you to why

it's such a tricky question.

And all the different ways that people are
trying to solve this unanswered question.

Since the time of Darwin, we've come to 
understand how life

progresses, changes, diversifies, finds
new niches, evolves greater complexity

and yet we still don't understand how to 
take that back to

the original formation and
initiation and origin of life.

So, in saying that it's important to
recognize that life lives on a spectrum.

And that spectrum goes from a completely
abiotic world

all the way up to multicellular creatures 
like us, and entire societies.

And at some point along this trajectory, 
we have this transition to something

that we would call life.

And so how is it that we go from this
abiotic world to a biotic world

understanding that this is all part of one
evolutionary continuum.

So why is that question so challenging?

Well, one of the things that makes it
challenging is that it requires

a lot of diverse types of knowledge to
begin to understand

this process and to answer this question.

And so those types of knowledge draw from
a variety of different disciplines.

Traditional disciplines.

So for example, we need to understand 
something about Earth science,

biology, chemistry, and physics and how
all of these different concept areas

intersect with one another and help us to
understand exactly what happened

when life first formed.

And throughout this course, we will
introduce you to the main questions in

each of these concept areas and how they
relate to the origins of life.

And we will also start to begin to paint a
picture of where the intersection and

synthesis of these different concepts live
hopefully moving towards a better theory

of how life started and evolved into
greater complexity.

So within these concept areas, what are
the main questions?

So if we take Earth science as a concept
area, the main questions,

as they relate to the origin of life, tend
to be things like

"what was the environment like during the
time when life originated?"

So we understand that the early Earth was
very different than the modern Earth.

And we need to understand something about
what chemistry was possible then

and how that might come together to help
life form in the first place.

Another question, is "in this early Earth,
what was the diversity and complexity of

various micro-environments?"

So if we think about the early Earth, not
only as a different average chemical

space than what we currently have, but
also lots of different unique types of

micro-environments existing in this very
different planetary environment, which of

those micro-environments were most likely
to give us life in the first place or to

have the right type of chemical complexity
to at least start down that trajectory

towards a living organism.

And then another very interesting question
is "once you get life in the first place,

once you get early life, how does it and
this geosphere, this environment,

start to coevolve?"

So we understand in the modern Earth, how
life interacts with the overall planetary

system, we understand through lots of the
history of life how life interacts,

has a large feedback with, and modifies
the geological environment and the

geosphere. And the question is when life
first started, "how did that--what did

that feedback look like and what did this
coevolution--how did this coevolution

happen and how important was that for the
specific trajectory that life took once

it was formed?"

From a biological perspective, the
questions we're interested in are mostly

how do we take everything we know about
modern life and try to look as far back in

time as we can? So how do we wind back the
clock on modern life to understand what

early life might've looked like?

So this involves taking a lot of
phylogenetic or genetic perspectives to

look back in time. It also asks--involves
asking questions like "what does the

composition structure and function of
modern life tell us about life's origin?"

Another way to say all of this is "which
aspects of modern life are general and

which are arbitrary?"

So, what are the features that we see in
modern life that are really essential to

life through any origin and trajectory and
which are contingent on the particular

evolutionary history that we happened to
have seen in--for more recent life.

Also in that vein, how do we take
everything we know about modern

evolutionary theory and start to
apply that to things like protolife which

might have a much less formal version of
inheritence or genetics,

how can we use evolutionary theory to
think about the simplest early life which

might be radically different but also is 
almost certainly undergoing some sort of

evolutionary process.

From a chemical perspective, our main
interest is "how does life arise from the

huge space of chemical reactions and 
compounds?"

So we understand that chemistry gives us
this really vast set of possibilities,

this really rich high-dimensional space,
which is great for allowing something

like life to form but it makes it very
complicated to understand exactly what

combinations and processes and
trajectories are actually necessary or

were the ones that led to the life that we
have.

Another question which relates back to 
Earth science is "what was early living

chemistry like? What was that-- how was
that possible in early Earth? And how do

we start to define sort of living
chemistry that isn't quite yet life?"

And then, a really interesting question is
"how do we go from complicated chemistry

or complicated chemical environment to
something that's even more complicated

and complex?" And that's the simplest
cells.

So even the simplest cells have a set of
chemistry and feedback and dynamics and

interconnections that is much more 
complicated than things that we see in the

environment and so how do we make that
transition?

Finally, from a physical perspective, the
questions we're interested in "are how do

physical constraints--for example, the
laws of thermodynamics--start to constrain

or bound the possibilities for life?"

So how do we take everything we know
about physics and use that to say what is

and isn't possible for life, especially 
as it first forms.

Another question is really to ask "what
can we take from what we know about which

processes are easy and hard in physics,
without any biology, to help us understand

what might've happened for life in the 
first place.

So for example, we understand that in
purely physical systems, it's possible to

get very rich pattern formation and
dynamics and so how much-- how important

are those sorts of naturally emergent--
occurring phenomena to thinking about the

first formation of life and how we start
to apply some of those concepts of

emergence and simple pattern formation to
interact with

how life began in the first place.

Another final question that physics-- or
final set of ideas that physics can lend

to us is "how do we take everything we
know about physical concepts, physical

laws and start to generalize those to use
them in a biological way?"

So how do we port physical concepts over
to biology in general and in particular,

how do we port those ideas over to the
origins of life?

So, as you can see this is a very rich
set of questions coming out of a variety

of concept spaces across a huge range of
science and in this course we've gathered

people from this wide diversity of
scientific perspectives to really layout

the details of each of these questions in
specific ways and then bring those details

together in a way that we have a broader
and more complete understanding of how

life might have formed in the first place.

And we certainly hope that you enjoy that
trajectory and this course overall.

So, thank you.