Welcome to Nerdology. I am Atila: Biologist, Researcher and what I will tell here It's just a theory. Today we will understand what the stars have to do with our evolution.
Oh, and before that, I HIGHLY recommend you watch the episode on Butterfly Effect. It is necessary! You've probably seen a lot of these astronomical photos, many of them taken by the Hubble Telescope.
What you may not know is that they are pictures of the past! Sometimes thousands or millions of years ago! Astronomy does not function as much of Physics, as Quantum Physics, for example.
If you have a hypothesis about how atoms work, you can blow some of them on LHC and test what you thought. Just pay a GOOD electric bill afterwards. But, if you hypothesize on how the UNIVERSE began, such as the Big Bang Theory, can not gather a cloud of gases and wait for them to merge.
But you can look back! That's because the astronomical distances are really . .
. Astronomical! So great that even the Light takes time to go.
The sunlight, for example, takes just over 8 minutes to get here. If Aliens invading our solar system drew a Smile in the Sun, it would take us 8 minutes to find out what happened. And the CUTE photos of Pluto, which we are receiving recently, took over 4 hours to get here.
And the further we look in the Universe, the more we are seeing in the past. The Pillars of Creation, for example, are 7,000 light-years away. That means the light from there takes 7,000 years to get here.
Therefore, the destruction that the Supernova in the neighboring of the Pillars caused there, 6,000 years ago, can only be seen on Earth after the year 3000. They probably no longer exist, but we can only know that in the future. Thus, astronomers make hypotheses about the Big Bang, a SCIENTIFIC theory about how it happened.
And since they can not directly test the hypotheses, observe the oldest galaxies, formed millions ago, or BILLIONS of years, to see if they fit what was predicted. Like the Galaxy EGS-zs8-1, discovered in May 2015, which shows how the Universe was over 13. 8 BILLION years ago.
It shows what the conditions of the Universe were like in your first BILLION year of life. Looking back, in this case, is much easier than going forward. From time to time they find a fossil of the Big Bang, like the Cosmic Background Radiation, which gives even more evidence for theories.
Instead of an immutable law, which can be tested and proven, the evidence of the Universe's past is used in a historical CSI, with a theory filled with observations and facts that reinforce the proposal. because of this, the scientific theories are different from what most people are referring to when they use the word, as Conspiracy Theories. In Biology, Evolution goes through the same challenge.
Because it is a slow process outside of the Pokémon World, it is very difficult to observe the Evolution going on around us. Sometimes we can see this in real time, like bacteria that digest nylon. As nylon is an artificial substance, which came to be produced in 1935, the bacteria that digested it, found in 1975, only had 40 years of evolution to develop this ability.
But most of the time, we can only look at the past. And just as astronomers can see millions of years ago looking at stars, we can see our past looking at the genes. As we explained in the episode about Butterfly Effect, every time we copy our set of instructions, the Genome, small mistakes are inserted here or there - the mutations, and are passed on, like in a Chinese whisper Just over 50 years ago, Linus Pauling and Emile Zuckerkandl demonstrated that the mutations incorporated in our genes can accumulate at a more or less constant rate, like the continuity errors of the Terminator films A Molecular Clock of mutations that marks the relationship between living beings.
By comparing mutations and differences between the genes of one living being and another, we can look at the past and estimate how long ago that gene was shared, besides comparing the estimates with fossils found. Suddenly, the relationship between living beings that we organized intuitively, like knowing that cats and dogs are closer than cats and pigeons, was explained in detail by comparing the gene sequences. When we compare the mutations between humans and the Neanderthals genome, for example, our relatives extinct 30,000 years ago, STILL have DNA in the fossils, and that was sequenced, we are comparing mutations that have accumulated between the last 500 thousand years.
Now, just as an astronomical hypothesis can be tested looking at the farthest stars in the past, all the hypotheses of the Theory of Evolution, can and have been tested by comparing the relationships between the genes of living beings. We have spent the last 50 years improving the ways of estimating time and evolutionary relationship through mutations. All the time, with each new gene found, with each discovery mutation, we test the validity of the Theory of Evolution, and we see how living things descend from a single common ancestor.
All living beings share DNA molecules which have been passed down from generation to generation for BILLIONS of years. Molecules that were formed by the atoms formed in the Stars and Supernovae that we observe, shared in billions of years, since a single explosion. Look up, or look inside, and you will see our past, and the SAME story: the continuum of cells, the ancestry of life forms and the stars of the universe.
And this is NOT just a theory! Do not forget to enjoy and share the video, sign our channel for more looks in the past, and until the next Thursday. This Nerdology was a sponsorship from Nerdstore.
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