Week 2 - Selection In Action

    For the second week, we were asked to watch a video on "Selection In Action". I am excited to see the video that told about how the corn was like in ancient times and the stickleback fish evolution. Those are some examples on selection. Darwin was talking about natural selection which by definition is, an evolutionary change that occurs through variation between individuals and some variants give the individual an extra survival probability. Now that made sense. Some evidences were drawn out such as in biogeography, the evidence was animals in Galapagos Island similar to South American mainland but very different to animals on other islands that have similar environment. 

  In the class, we had done some interesting activities. Some terminologies that were once blurry now seem to be understandable. For instance, I had knew that artificial selection means the action of choosing the desirable traits by an outside source other than the organism itself. Meanwhile, the struggle for survival was survival of the form that will leave the most copies of the fittest in successive generations. I also discovered the four main principles of natural selection. Firstly was the variation which means a term used for genetics that causes the individuals or groups of a certain type or species to possess different characteristic from one another. Second was overproduction, the ability of species to produce more offsprings. Next was adaptation that means the characteristics which allows individual to survive better than others. Lastly the fourth was descent with modification. It means passing down adaptation from one generation to one another.

Proceeding with the next activity, I discovered some terms that I had never encountered before such as homologous, analogous and vestigial structure. Homologous structure is similar structure and position but different function because derived from a common ancestor. For example, arms in human and wings in bats have similar position and structure but obviously used for different functions. On the other hand, analogous structure is similar function but different origin due to an uncommon ancestor such as birds and bats both use their wings to fly. Besides, there is a vestigial structure which means structures exist in organisms that have no apparent function at all, appearing to be residual parts from a common ancestor like wings in flightless birds. 

  For the last part in this first topic, we learnt a little bit about the modern technologies used to create a better understanding about evolution. Those technologies were include DNA sequence analysis, pseudogenes, homeobox genes and protein comparisons. My understanding was crystal clear when we were assigned a group assignment on a comic strip about how evolution is connected with natural selection. 

My group had done about the adaptation of white and black peppered moths. Once, white-peppered moths were the majority. Meanwhile black-peppered moths numbers were declining because they were eaten by birds. The coloration of white coloured moths had deceived the birds. But the happy one will not always be happy to the end. Life is a rotating wheel. As pollution polluted the environment, all rocks and barks turned black. Now, the camouflage ability was played better by black-peppered moths. This example did give me an idea about survival of the fittest.

  Finally, as the topic of evolution had come to the end, I hope to discover more and wished Icould involve myself in research by using those modern technologies that have been discussed. This topic is really interesting for me as it contains something relatable with all living things.