Some things that molecules do

This is going to be a different type of blog. Its going to be different in the sense that I'm going to be explaining one of the episodes of the new Cosmos television series, one which I thoroughly enjoyed and feel like it should be shared with more people. This episode was titled: "Some things that molecules do". I'm reviewing this episode rather then a chapter of the book because Sagan touches quite heavily on the topic of evolution in the original cosmos, so i figured that reviewing the episode would have a similar effect as to reviewing the chapter in the book. 

One of the more interesting things that this show featured was how wild wolves evolved into domesticated dogs which we know today. What originally happened when dogs first came to be were wolves which weren't  afraid of humans had an advantage over the ones who were. Humans offered a source of food wherever they went, and also offered some protection from other wolves whom weren't so brave when it came to humans. Gradually, wolves became friendlier and friendlier to humans, eventually becoming hunting partners and symbiotically helping each other hunting and gathering food. We assume that this all happened around 8000-13000 years ago, just around the time that people were starting to settle down and start making towns and cities. 

One of the most prominent arguments against evolution and natural selection are the existence of unbelievably complicated organs which we have, such as the eye. The eye is such a specialized and fine tuned organ that there is no way that something like this could have come from mere chance... or did it? The fact of the matter is that the eye ins't actually perfect. There are hundreds of improvements which could be made on the eye all of which would make it more efficient and effective. The show then proceeds to outline the progression which the eye has had, from the first light-sensitive cells to exist, all the way to the we which we see in most animals in modern day times. 

One of the more interesting topics that was discussed in the show were the 5 major mass extinctions which have occurred throughout the earths existence. Everyone has heard of the infamous ice age that supposedly wiped out the dinosaurs, however the ice age pales in comparison to the rest of the 5 major mass extinctions. One which was focused on in the show was the Permian- Triassic event, more commonly referred to as "The Great Dying". During this time, 57% of all families, 83% of all genera and 90% to 96% of all species went extinct. This mass extinction was caused by a sudden release of methane gas that made most

 of the habitats on earth unlivable. There was one animal in particular though which has survived and flourished in circumstances just like these. The tardigrade is undoubtedly the toughest animal to ever live. They can survive in nearly any habitat imaginable, from the antarctic to death valley, they can even survive in the vacuum of space, these guys have been found, everywhere. 

I encourage all of you to watch this episode here!