Another aspect of genomics is evolution.
Evolution is a very broad topic.
When we're talking about evolution of genomes,
we talk about how genomes themselves change over time, and we usually mean over
evolutionary time, and those are very, very long time periods.
We know from having sequenced the human genomes, and now having sequenced many
humans individual genomes that all of us are nearly identical to one another.
So our genomes from generation to generation barely change at all and
most of those changes are small, random changes which don't have any effect.
But we can compare our genomes to genomes of other creatures
such as chimpanzees which are our closest relatives.
Diverge from us approximately 6 million years ago.
And we can compare our genomes to genomes of much more distant things like
fruit flies, nematodes, or even bacteria.
And when we do that, we discover that, we share a surprising amount of sequence.
Similarly, even with things as remote from us as bacteria.
And when you think about it, that sort of makes sense because the, even though,
we're, obviously, very different from bacteria, we do very,
very different things, every living thing on the planet uses DNA as its basic code.
Every living thing on the planet has to do certain things in common because of that.
For example,
every living thing has to copy its DNA in order to make copy of cells.
So bacteria use a very similar mechanism to copy DNA as, as humans,
so we find the genes in bacteria are, in those cases, similar to genes in humans.
[SOUND] And then finally, when we talk about mapping genomes,
we're actually beyond, mapping sometimes refers to just sequencing itself,
capturing the sequence, but once we capture the sequence,
the first thing we do after that is try to figure out where the genes are,
and we'll talk a lot more about that later in the course.
But, genes the word genes has, has changed a lot over the past 50 to 100 years.
Today, we think about, one way to think about it is, is say an inhe,
inheritable unit that is something that you can inherit from your parents.
Another way to think about is, is a small section of the genome that encodes
a protein which in turns does, has some function.
And that's usually what we're talking about and genomics is,
is the parts of the genome that encode proteins or
that encode little bits of sequence that can turn into functional elements.
[SOUND] So here's another definition of genomics that emphasizes not just
the study of genomes themselves but also a little bit about for application.
So why are we interested in genomes at all.
There are many, many applications of genomics, today, and the,
the list is growing, rapidly as, as we get better and better at sequencing, and
as we discover more things that we can do with genomes.
But it certainly includes medicine, many applications, in,
in pharmacy, and if you're not looking at human genomes, agriculture and, and
other areas of science.
So genomics is a relatively new field of biology.
But it's in some in, in many people's minds, it's part of biology.
But let me just emphasize a few of the differences between genomics and
more traditional biology and genetics, which have a big overlap.
So one way you can distinguish genomics from more traditional biology.
Genetics is the, traditionally when we, when we study genomes, or genes,
we studied one at a time.
Not that long ago, back in maybe the 1980s, it was a common,
a common experiment was to, to study one gene and to spend months or
years studying that one gene, or people would spend their whole careers.
You've been studying one gene and writing about that gene, and
trying to figure out what that, what function, what the function
of that gene was in said people or in say, a model version like mouse.
But today, because we can capture the whole genome,
we often look at all the genes at once or at large collections of genes all at once,
so that would be a more genomics way of studying.
The technology has been the real driver of this, so that's a very big differences and
that's really what's allowed genomics to grow the way it has the past 20 years.
In the past, we could only do targeted, what we call low throughput experiments,
studying one gene at a time instead of one organism.
Today, we can do experiments where we simultaneously measure the activity of
thousands of genes all at once using the new genomics technology.
So that's a big difference between genomics and
earlier ways of doing biology.
And then the hard part, where things differ between traditional and
genomics science.
In the past, you still had to be clever, you had to understand biology and
genetics well.
Experiments were not necessarily easy to do.
Might, they might take years.
Today, some of the experiments, you can still do the same kind of experiments,
some of the experiments are easier to do, but we generate so
much data that the data itself is overwhelming.
So, because the technology has gotten very clever, very efficient, and
very expensive, we're now looking at doing experiments where we,
where we measure thousands or tens of thousands of genes all at once,
in multiple tissues, in multiple samples.
And we know going into such experiments that there's probably a lot of
really interesting results that are going to come out.
But when we get the data, we discover that, oh my god, there's so
much data here that it's hard to figure out where the interesting results are.
So we have,
we have to deal with big data problems that we didn't have to deal with before.
We have to deal with,