In today's video we're going to talk about
biology and life.
Since we're at the start of our biology course,
it would be a good time to talk a bit about
what biology is and that includes also discussing
science.
So biology is the scientific study of life.
And so, what does it mean that biology is
a science?
Well, a science is a systematic method of
inquiry what that means is that science is
really a way of asking questions and then
answering those questions.
This is done through a series of steps known
as the scientific method of inquiry.
Scientific knowledge and discoveries are obtained
by following these steps.
And this is true for all different aspects
of science.
The scientific method is how we go about performing
science.
Now depending on which textbooks you use sometimes
it will list four different steps to the scientific
method sometimes it'll list five different
steps, but regardless of the number of steps
it always needs to start with observation.
Sometimes scientists may spend their entire
career simply making observations and recording
them and sharing those observations with others
and that's a great way to build foundational
understanding in a field.
Observation really is the key to making something
a science.
And as we'll learn, there are many ways to
make observations.
Most common would be using our own senses
our sense of sight our sense of hearing our
sense of touch.
Yet we do also have specialized detection
equipment which allows us to extend our senses
beyond what we would normally be able to detect.
Whether these are microscopes which allow
us to see very small objects or telescopes
which allow us to see very distant objects
or even different pieces of equipment that
can allow us to maybe visualize something
that we wouldn't normally be able to see such
as electrical currents or magnetic fields.
These all allow us to make observations.
Now these observations typically lead us to
ask the question “Why?”
By observing nature and the natural world
we develop questions.
These questions may have to do with common
occurrences or events, such as, usually when
I go outside the sky is blue.
Why?
Or when I see groups of birds migrating overhead
they're usually flying in a V shape.
Why?
These common occurrences can lead to questions
but suppose instead maybe you went out to
Lake Mead or some other body of water and
instead of seeing the lake in its usual state
you go there and the surface of the lake is
just covered with dead fish, tens of thousands
of dead fish.
That would be out of the ordinary.
That would be different that would inspire
you to ask the question “Why?”
So questions can sometimes be inspired by
events that seem different or out of the ordinary.
Regardless of the origin of the question,
once you have that question of why, our next
step is to give it our best shot.
Attempt to answer the question based on what
we know.
So once we have a question the next step is
to make a hypothesis.
So what is that?
What is a hypothesis?
Well, a hypothesis, first off, it's an answer
to the question that came from our observation.
Now you may have often heard of a hypothesis
described as an educated guess and that's
a good definition of it.
But one thing that's included within this
definition that you may not always be aware
of is that a hypothesis is based on knowledge
you already have.
Once you have the hypothesis you can then
make predictions.
So predictions are what we will end up testing
using experiments.
So predictions, they're based on the hypothesis
and the prediction will often sound something
like this: “If our hypothesis is correct
then we would expect to see this certain result
when a particular event happens.”
These predictions then need to be tested to
see if our hypothesis is correct.
So testing of predictions happens in the experiment
phase.
Experiments are design to test the predictions
which were based on our hypotheses.
Now a few things about experiments, first
off they are not accidents.
While it's true accidents can sometimes lead
to new observations and that in turn can lead
to new questions an experiment itself is designed
an experiment has a purpose and the purpose
of that experiment is to test the prediction.
Good predictions lead to good experiments.
So, we've performed our experiment.
Then what?
Well upon completing the experiment our prediction
is either going to be proven correct or incorrect.
If our prediction is supported we then typically
make another prediction 
using our same hypothesis and plan another
experiment often our goal is to get as much
supporting information as possible so that
we can know our hypothesis is on the right
track.
However, if our prediction is not met in that
experiment if we are incorrect, we need to
rethink our hypothesis.
Now at first, this might sound really bad.
It's like “If we fail in our experiment
we're back with nothing!?!”
But the thing is, it's not that we have nothing.
We now have new information.
We have new knowledge.
We can go back to that original problem and
approach it with this new information that
we've gained and come up with a better more
accurate answer to that question.
This is the scientific method.
So looking at an example of this, Imagine
you have a flashlight and you go to turn that
flashlight on you flip the switch … and
nothing happens.
There's no light and you say “Hmm, why doesn't
my flashlight work?”
That's the question, “Why?”
Your hypothesis is then based on your knowledge
and experience of flashlights.
You know, “Well, they run on batteries.”
So maybe something is up with the batteries?
Your prediction then becomes, “If I replace
these batteries with new fresh batteries then
I think the flashlight will work.”
And that actually then becomes your experiment.
Do just that.
Take out the old batteries, put in new fresh
batteries and flip the switch.
One of two things is going to happen.
Either the flashlight will turn on or it won't.
Now if you turn on, if you flip that switch,
and the flashlight turns on, then your prediction
and your hypothesis were supported.
Something was up with those batteries.
Now you could do further testing, if you wanted
to see if all of the batteries were dead or
just some of the batteries were dead.
But you have new avenues you could pursue,
but regardless, your flashlight is working.
But let's say instead of that other situation
you put in new fresh batteries you flip the
switch and still nothing.
Nothing happens.
Well at this point you can rule out the batteries
as being the reason for the flashlights not
working.
Maybe the switch itself is broken?
Maybe the light bulb is burned out?
These are other things you can then go on
to test to figure out what's necessary to
get that flashlight working again.
Now, that last example maybe seemed a little
artificial or not not really biology-focused,
but we use the scientific method in our daily
lives all the time.
So, a slightly more biologically relevant
example.
Remember a little earlier when I talked about
going out to a lake or a river and seeing
the surface of that body of water just covered
with dead fish, well those sorts of things
can happen and have happened in the past.
We call these massive fish die-offs and in
the early 1990s there were massive fish die-offs
in many bodies of water in the North Carolina
area.
Now these fish that were dead, it's not just
that they were dead, but they had these big
open sores on their side and they would die
off in mass numbers.
Now, many different people saw these dead
fish and they all had the same question, “Why?
What happened?
What caused these fish to be killed?”
And there were many different hypotheses.
Some people claimed pollution, some people
blamed birds, some people blamed insect parasites.
Well there's a group of researchers who were
familiar with the fish in that area.
Dr. Burkholder and her associates, they had
in their own laboratory setting, seen fish
die in this way previously and they had tracked
it down to a specific type of microorganism
called a protist.
So based on the experiences and the knowledge
of her and her fellow researchers, they came
up with a different hypothesis.
That these fish were dying off because of
the protists.
Now if these fish are being killed by protists,
then we'd expect to see increases in the number
of protists at the time of the fish die-off.
We would also expect that if we added these
protists to an aquarium containing the same
type of fish, well, it would cause death for
those fish as well.
These are predictions 
based on their hypothesis that it was these
protists causing the fish to die off that
they could actually test.
They could perform these experiments and look
at their results.
And sure enough, they did find that it was
in fact protists leading off to those fish
die-offs.
Now that then opened up the whole nother series
of question.
“Why is it that the protists started killing
off the fish?
Were the protists always there?
Were they newly introduced?
Why is it that now things are different than
they were before?
And each of these questions can be approached
using that scientific method.
Now that we've talked a bit about the scientific
method and how it works, it's time to discuss
just a bit the limits to the scientific method.
Now the scientific method is great for studying
the natural world, for studying things that
are observable and repeatable and testable,
but there are many aspects of life in society
in which scientific analysis is not the best
way of answering those questions.
For instance, science cannot make moral judgments.
Science can't say whether something is morally
right or morally wrong.
That's in the realm of philosophy, in sociology.
That's not in the realm of natural science.
Also, science cannot prove or disprove faith-based
beliefs.
If we're talking about something that cannot
be repeated, cannot be observed, cannot occur
again, that's sort of outside of the realm
of science.
Another thing that science doesn't have a
say on is personal aesthetic values.
Science can't say which style of music is
the best.
Science can't say whether a picture is beautiful
or ugly.
Those are in the realms of personal aesthetic
values.
Now a friend of mine posted this picture a
while ago.
“Science can tell you how to clone a Tyrannosaurus
Rex whereas Humanities can tell you why this
might be a bad idea.”
Now it's not saying that all science is foolhardy
or shouldn't be attempted, but don't leave
it to science whether something should happen
or not.
Science just tells us if something can happen.
Thank you all very much for your attention.
I'll see you in the next video!
