Stated Clearly presents: What is Chemical Evolution? Scientists have reason to think that the
first living cells on Earth came about through a natural process
called Chemical Evolution. What is Chemical Evolution, how does it work, and how is it different
from Biological Evolution? To answer these questions we'll start by
first dissecting the terms and then look at an example of how
Ehemical Evolution can take simple molecules and organize them into complex
structured systems, similar to those found in living cells.
The word "Evolution" simply means change over time. Biological
Evolution deals with changes in things which were able to reproduce: living creatures make copies of
themselves. The change over time that we see in Giological Evolution is not just random change, oftentimes it is adaptive change. Populations become
better able to survive and reproduce within their environments. When conditions are right, biological
evolution can even drive a species to develop brand new characteristics and abilities. For this to happen, biological evolution typically requires
three conditions: Reproduction, variation, and selection. Let's see how this works: Many species of
Holly have smooth edged leaves. English Holly, however, is covered in
spikes which protect the plant from deadly
predators. How did these weapons first evolve? Well, when a holly plant reproduces its offspring often show a random
variation. They are slightly different from their parents, and slightly different from each other.
In a forest filled with grazing animals, individual plants which happened to be
harder to eat then their siblings are more likely to grow up and have
children or their own. Nature, simply by being difficult to
survive in, selects who gets to reproduce and pass
on their new traits and who does not. In this case mutations which simply caused the vanes
that these leaves to extend past their edges, gave rise to a brand new weapon! The discovery of biological evolution
was an incredible breakthrough in science. It explained how new complex traits and
abilities develop naturally in living things. The
problem is Biological Evolution depends on
reproduction in order to work. Reproduction however, is
an extremely complex process in another itself. This begs the question: How did
reproduction first evolve? To try and solve this mystery, many
scientists are looking into Chemical Evolution. Chemical Evolution refers to changes in things that need
not be capable or reproduction. Examples could be individual molecules
or entire chemical systems. A chemical system is a group of
molecules that interact with each other. Molecules, structures, and chemical systems almost always
evolve or change over time, but they often evolve towards simplicity. Solid iron corrodes into rust when it
comes in contact with the water, proteins breakdown when exposed to too
much heat. If simple chemistry is to give rise to something advanced enough
to reproduce, there must be situations in which
chemical systems can grow in complexity, form new structures, and gain new
functions. In order for this to happen, reproduction,
which is needed in biological evolution, can be
replaced with a much simpler process: repetitive production. On planet Earth and all throughout the
universe, powerful natural events take place in regular cycles: The heating and then the cooling of day and night. The repetitive
eruptions a volcanic geysers, the rise and then the fall of ocean tides. These events repetitively produce, or give birth, to
new molecules and chemical systems. These products
increase over time and often develop new abilities as they
interact with their environment. let's see an example of how this process
works! This here is a special molecule called a fatty acid. It's a collection of
carbon atoms, hydrogen atoms, and oxygen atoms all stuck together in a specific pattern. Fatty acids are one of many complex
molecules that living cells use inside their bodies. They build fatty acids with atoms they get
from their environment. Scientists used to think that living
cells were the only things able to consistently built fatty acids, but check this out! Lab experiments have
shown that when simple common gases: carbon monoxide and hydrogen, are heated
up with minerals like those found in the Earth's crust, a variety of complex carbon molecules including fatty acids began to grow! Living cells are not needed! This can
happen naturally in underground chambers heated by the Earth's Magma. As
pressure builds, these molecules can belch up into pools
of water where a simplified version of Natural Selection then takes over. Most particles blasted
into water will either float or they will sink. Nature
selects against them staying in the watery environment. Fatty Acids however, remain suspended in
warm water, growing in number as the cycle repeats. When fatty acid concentrations are high
enough, they bunched together automatically self-assembling into a
stable ball! This happens because water molecules are
attracted to the oxygen heads of the fatty acids sorta like a magnet, but water repels
their oily carbon tails. When fatty acids pass near each other,
their tails are pushed together by water eventually forming a ball. As fatty
acid collections continue to increase, they join together to make a large skins! If fluctuations in the skins happened to make the edges touch, water forces those edges the fused
together the end result is a stable hollow
container similar to the membrane, or skin, of a living cell! These containers have a brand new
ability. They can trap other molecules inside, acting as an entirely new environment
for chemical evolution to continue working within! It's important to note that these
membranes do not qualify as living creatures. They can't reproduce on their own the
same way living cells do. That said, the development of these
membranes along with many other molecules and
chemical systems that scientists have observed, demonstrate an extremely important
principle: Chemical Evolution can give rise to new characteristics and abilities. Because of this, scientists hypothesize
that under the right circumstances chemical evolution could give rise to
systems that are fully capable of reproduction! If they are correct, this would bridge
the gap between Chemical Evolution and Biological Evolution, demonstrating
that chemistry can indeed give rise to life! Scientists at the
Center for Chemical Evolution and other research groups around the
globe are working hard to test this hypothesis. So to sum things up, the main
difference between Chemical Evolution and Biological Evolution, is that Chemical
Evolution can produce new characteristics and abilities without depending on reproduction. Because of this, Chemical Evolution is being investigated as a possible cause for the origin of
life. I'm Jon Perry and that's Chemical Evolution Stated Clearly. This animation was funded by the Center
for Chemical Evolution, the National Science Foundation, NASA, and contributions from our viewers. Though we do receive grants from time to time, Stated Clearly is mainly funded by our viewers. If you'd like to help out, visit us at
statedclearly.com and click contribute. Special thanks goes
out the Tyler Proctor who volunteered to work on sound for this
project and to our team of science advisors Christopher Parsons, Dr David Deamer, Nancy Miorelli, Dr Nicholas Hud. and Dr Ram krishnamurthy. Until
next time, stay curious!
Fascinating ! Great channel.
https://www.youtube.com/watch?v=e91D5UAz-f4&index=11&list=WL
Very interesting. Very very interesting. Thanks OP
This is the coolest thing I have ever seen.
So the hypothesis is that "cells" (non-living) can be formed from groupings of things like fatty-acids. He mentioned that it has not been proven that those fake cells could lead to live-cells, but does anyone know how that might happen or if there's any theories about it?
something happens here and there and boom, self assembly RNA!
Fantastic video. Learned a lot.
This changes everything.
Is there a subreddit for such videos?