Shkelqim Hajrullahi: Hi there, Shkelqim here. Ever
wondered how fossils look like? They look like this. (Show 2 pictures of
fossils.) I agree. They can be very interesting to look at. Fossils are the
preserved remains from dead organisms, which makes them quite old too. (Remove
the 2 pictures that are shown on the screen.) How do we know how old they are?
Well, there are several methods of knowing how old an object is.
A common method
we use is called radiometric dating. You just measure a radioactive compound, which
is a substance that breaks down in a predictable manner according to how much time
has passed. For example, carbon-14 is such a compound. About every 5730 years
half of the carbon-14 that’s inside a dead organism will have broken down. If
you know how much carbon-14 there was at the time of death, then you can
compare that to how much carbon-14 there is left and thereby estimate the age.
Another method that is common is amino
acid dating. The main building blocks of all living organisms, called proteins,
are built from amino acids. Most of these amino acids can exist in two
different 3D-forms, the L-forms and the D-forms. With only very few exceptions
the amino acids inside all living organisms consist of the L-form variety. The
D-form is simply not used in the vast majority of organisms. These two forms
are not stable and spontaneously turn from one form to the other based on how
much time has passed. This is not the case for as long as the organism is
alive. When an organism dies the L-forms and D-forms stop being managed by the
dead cells. Initially, the amino acids are in the L-form. At the point of death
the amino acids begin to turn from their L-form to their D-form. Of course,
some of amino acids in their D-form also turn to their L-form, but since there
are fewer amino acids in their D-form this happens to a lesser extent. This
process continues on gradually over time until it reaches equilibrium, meaning
that equal amounts of amino acids turn from one form to the other. Depending on
how far along the reaction has gotten towards equilibrium we can estimate the
time of death.
There are many more methods that can
be used in dating fossils. But, far more interesting is what the fossils reveal
to us. Essentially, each fossil reveals what lived during that time and how the
living organisms changed over time. When comparing two fossils that come from
two different species it becomes clear that they are related to each other in
some way since they are so similar. Not only that, you can see that species come
into existence only to vanish later on. How can that be? How can species of
organisms just pop up as fossils in a given time period and then later on
vanish so as to not leave any fossils in another time period? And, why are
older species just replaced by newer species that are extremely similar to the
ones that vanished? It’s almost as if there is a very slow and gradual change from
one generation of organisms to the next. It’s almost as if they slowly evolved
through time. Hmm… could it be evolution? Well, that is precisely the case.
Organisms evolved as time went on. The ones who failed to evolve sufficiently
enough died out. The ones who did evolve, meaning that they successfully
adapted to their environment, survived and replaced the ones who died out.
If fossils were all the evidence we
had in support of the theory of evolution then it wouldn’t be much of a scientific
theory. Luckily, we have far more evidence at hand in support of this theory.
For starters, we have DNA, which is what our cells have as a means of storing
the functional instructions of the cells. In short, the DNA is the instruction
manual for how cells are to function. Not only that but how our DNA is read,
called the universal genetic code, when the goal is to produce proteins is almost
completely identical in all organisms and cells. This means that cells and
organisms not only use the same type of instruction manual as every other
organism and cell but that also the instructions are read in an identical
manner. Even more unambiguous is the composition of the DNA itself. Even though
DNA could be made from many different forms of bases, meaning different
building blocks, which could differ from one species to another this is not the
case. Almost all cells and organisms known to man use the same 4 bases, which
is quite remarkable and greatly supports the theory of evolution. Even our
genes, which is a specific stretch of DNA that codes for a certain protein, supports
the theory of evolution. Comparisons of DNA and genes between different species
shows that different species have much more in common than would be expected by
chance alone. For example, we humans and fruit flies have about 60% of our
genes in common, meaning that we have more genes in common than genes that
actually differ between humans and fruit flies. Lending even further support to
the theory of evolution is what machinery the cells use to build proteins. Protein
synthesis is done by ribosomes, some sort of complex machinery that
manufactures the proteins themselves. The ribosomes between 2 different species
are so similar, oftentimes indistinguishable, that if any human cell for some
reason lacked their own ribosomes then it would be entirely possible to just
inject ribosomes from a different species and the injected ribosomes would work
very well, if not just as well. These are just some few examples and all of
this just scratches the surface. Almost all of physiology, the science of how
living organisms function, reflects and supports the theory of evolution.
If you don’t really get what all of
this with DNA and genes means, let me use an allegory to illustrate what I
mean. If you look into a book you can think of the book as one cell and the text
as the DNA in one cell. How the DNA is read, the language, is the universal
genetic code. One sentence would be one chromosome, which is one unbroken chain
of DNA containing many genes. The words themselves are the genes and the bases
are the specific letters. We use letters to construct words, which are used to
construct sentences and finally all sentences are collectively called a text.
In the same manner, bases are used to create genes, which construct chromosomes
and the chromosomes are collectively called the DNA in one cell. This may help
if you’re having trouble figuring out the meaning of these words.
Anyone that still doubts the
validity of the theory of evolution can simply go ahead and test the theory
themselves. It’s quite easy to do so. Just take a species of bacteria and expose
it to something toxic, like antibiotics. If you did that the bacteria would die,
but occasionally some would survive by adapting to the antibiotics. This
enables you to see evolutionary principles at work without having to wait for
years on end. This is actually what has happened when you hear that some
bacteria have become drug resistant bacteria. When that happens you can try to
kill these bacteria by exposing the bacteria to a different antibiotic, meaning
some drug that the bacteria hasn’t adapted to since it hasn’t been exposed to
the drug.
We humans have actually been using
evolutionary principles for a long time, starting before we even had the
concept of evolution. For example, humans started breeding the gray wolf far
prior to Darwin publishing his very famous book “On the Origin of Species”. (Show
picture of the evolution of domestic dogs from the gray wolf.) By selectively mating,
that is breeding, based on one or several desired traits we humans succeeded in
breeding the gray wolf so as to create the modern domestic dog breeds. In fact,
all of the domestic dogs are part of the same species and came from ancestral
gray wolves. (Remove the picture that is shown.)
Finally, let me mention vestigial
structures. Vestigial structures are anatomical components of organisms that
still exist in a species but which have lost all, or almost all, of their
function in the course of evolution. (Show picture of a whale with its
vestigial legs.) For example, whales have degenerated bones similar to legs
that serve no function. It only makes sense that they still have these false
and useless legs if they evolved from a species which used those legs at one point
in time and then later on the legs degenerated when those legs no longer served
any function and only were a hindrance. (Remove the picture that is shown.) Another
example would be the ostrich with its wings that no longer are capable of
making the ostrich fly. Again, it only makes sense if they evolved from a
species that could fly.
Much more evidence is available for
those of you who are interested and want to know more. As for now, that should
more than suffice as evidence in favor of evolution, especially since there
exists no empirical evidence to the contrary. Just let me add one thing before
the end of this video. I do know that very few people will be swayed by a video
explaining the logical basis and evidence for evolution, be it this video or
any other video. I only wish that you think about the arguments made, not that
you agree with them. Even if you disagree with me I only request that you don’t
feel hateful prejudice towards us who believe in evolution just because we use
logic and follow the evidence. It wouldn’t be so important for many atheists,
including myself, to convince religious people that they are wrong if it weren’t
for a lot of religious people wanting to force their beliefs onto others. If
you could just respect that some people want to use reason and evidence when
drawing conclusions, I would be fine with other people thinking that faith is
the right way to go. You can have your religion and your faith as long as you
don’t try to force it on me and take away my usage of reason and evidence. You
might not know this but some of us value logic and evidence just as highly as
you value your faith.
For those of you who want a transcript of this video please look down below the video. Please try to watch my videos in the order that I’ve uploaded them since you need to watch some of my older videos if you want to fully understand the content in some of the newer ones. Don’t forget to donate so as to support and motivate me in further production of quality videos. If any of you donate and contact me afterwards, I just might listen to any request of video topic you might have. See you later. May knowledge and virtue find you.
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Riding a Dinosaur to Work - Evolution 02
Shkelqim Hajrullahi: Daisy had just woken up from a nice
dream. She was in a good mood and put on a casual dress since is looked to be a
warm summer day. Once she had combed through her hair she went to the kitchen. Then
she started making breakfast for herself and her 5-year old son. When she was
almost done with the bacon and eggs she started screaming towards the stairs
that were close to the kitchen.
Daisy: Luke, Luke, come down and eat
your breakfast!
A few minutes later Luke came
running down the stairs and sat down to eat. He was hungry and swallowed the
food without chewing much.
Daisy: Sweety, don’t eat so fast or
you’ll choke.
Luke answered her only with a small
burp. When he was done he stood up and started running towards the entrance
door. He stopped when he heard his mother’s voice calling after him.
Daisy: Sweety, come back. Go
upstairs and put some clean clothes on. We’re going to the museum today. And don’t
forget to comb your hair.
Luke: But, mom. I want to go out and
play.
Daisy: You can do that later. I want
you to learn a lot while you’re still young. Going to the museum will teach you
a lot. It’s going to be fun, sweety.
Reluctantly Luke did as his mother
told him. 15 minutes later Daisy and Luke were ready and left their house. Luke
was too energetic and ran around his mother while she walked.
Luke: Mom, mom, what’s a musem
thing?
Daisy: It’s called a museum, sweety.
It’s a place where you can see very old things and learn about how people lived
many, many years ago.
Luke: What kinda old things? Are
there swords there? I want to see a sword.
Daisy: No, sweety. This museum has
no swords. It’s a museum about dinosaurs.
Luke: What’s that?
Daisy: Old and big animals that lived
long ago. All of them have died so now we can only see their bones in museums.
Luke: They are big? Wow. I wanna see
that.
They had arrived at the museum,
which had a statue of a man riding a dinosaur in the front of it. They entered and
Luke immediately started running to the first dinosaur that he could see.
Luke: Mom, mom, what’s this. It’s so
big. Wow.
Daisy: That one is called a T-Rex,
sweety.
Luke: Why is there someone there?
Luke pointed to a human doll that
was placed on the back of the T-Rex.
Daisy: That’s only a doll. It’s
there so that you can see that we rode the dinosaurs long ago.
Luke: We lived together with them?
Daisy: Well, of course. We have
their bones here so we know that there were dinosaurs once upon a time, sweety.
When god created the world he made us the rulers of everything in the world.
So, of course we ruled over the dinosaurs too.
Luke: Wow. You’re so smart, mom.
Thank you for teaching me. They look so cool.
Daisy: Oh, you’re so sweet. I’d do
anything for you. I want you to become a smart young man when you grow up. Do
you know why we rode them?
Luke looked confused and shook his
head.
Daisy: We had no cars then so we
rode the dinosaurs to work and to buy food. Smart, right?
Luke: Yeah, you… like… know
everything. When I grow up I hope I become smart just like you, mom.
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