COSMOS: Episode 2
Posted by Biology SL on Tuesday, April 29th, 2014 at 3:49 pmin
The second episode of Cosmos talked about the evolution of species. This relates back to the option chosen for our IBDP Biology course, Option D: Evolution. The episode begins by talking about artificial selection in wolves and continued on to talk about natural selection in polar bears. Finally, the episode shows extinctions of animals.
I was interested in the way the wolves evolved into domesticated dogs. It was interesting that the less violent wolves were the ones more likely to survive alongside humans, and evolved into domesticated dogs. I always thought that evolution was the “survival of the fittest”, which I always interpreted as the strongest and largest animals. However, after watching this episode, I found out that smaller animals can also survive, as long as they have a certain characteristic which benefits them.
I knew that polar bears evolved from normal bears, but I didn’t know that their fur color were a simple accidental gene mutation. It’s interesting to think that simple accidents can affect the survival of a whole population. Just from a small accident, the polar bears were able to catch their preys easily compared to the brown bears. I was also able to review a bit on genetics from the small section on the gene mutation in the polar bear’s egg.
The most interesting part of the whole episode for me would be the part where the host talks about how eyes evolve. I find it really interesting that our eyes aren’t as “perfect” as I expected. It turns out, our eyes were originally made to work underwater. As we evolved into land animals, our eyes were slowly adjusting, but wouldn’t work as great as it would underwater. This was because evolution didn’t start over. Instead, it changes bit by bit in our gene. I think that this part is really important as it shows that all living beings adapt. We are probably still evolving at this moment without realizing it.
There has been 5 mass extinctions in the history of the Earth. Apparently, one tiny animal known as the tardigrade was able to survive all this. The tardigrade can survive in many different conditions, from the cold ice to hot lava to even outer space. I find this creature quite cute but also interesting. This tardigrade is proof that with the right genes and characteristics, living things can survive in many different conditions.