WEEK 2 - COMIC ASSIGNMENT and Topic 1 : History of Life Part I

REFLECTIVE JOURNAL - WEEK 2

Hello readers,

We've got an assignment which we were asked to make a comic related to natural selection. So my group decided to create a story of two populations white and black peppered moth living peacefully in same area. Unfortunately, population occurred where the factories had released too many of soot until the trees at the forest became sooty. The population of white peppered moth extremely decreasing due to the insufficient hiding place from the predators. This is because their appearance are too obvious and attractive for predators to catch them compared to the black peppered moth body which is closely and almost same color as the sooty trees.

The second topic of Cell and Development Biology is History of Life. This topic is divided into two division which are

1. History of Life - Part 1 
2. History of Life - Part 2 (Systematic, Taxonomic and Classification)

History of life - part 1

• Have you all imagine how life's form? 
• For the first time by referring to this topic, i'm so curious and think what is actually had happened billions years ago? 
• How was it happened? 
• What is the thing that induced it to happen? 
• How can earth finally turns out like now? How? Why? 

For the first part we had learnt about how did life begin which is the 'the origin of life'. The most important thing that i realized, not all we had naturally nowadays like Oxygen (O₂ gas) is already present itself on the early earth. It surprised me a lot. 

By looking the graph of time-line for the origin of life, i tried to relate it with human evolution theory from the first topic. At what duration of time did human exist actually? It also may took sufficient of time to evolve right? i think it is the biggest and hardest evolution. Ya at least I could know my ancestor's birthday roughly.

Overall based on what I've learnt, the life's begin from the molecules to cells.

                                                 INORGANIC MATERIALS

↓

 chemical evolution occurred 

- life can not survive

-earth is not condusive place for life

↓

ORGANIC MOLECULES

↓

biological evolution occurred  

-life comes out

-about 3.8 billion years ago

↓

LIFE

↓

natural selection and mutation occurred

↓

DIVERSITY 

It's not on the lecture notes but I've been told by Prof Madya Dr. Parameswari that it's took about 1.1 billion years for the chemical reaction the inorganic molecules to accumulate and react before the life started. It's already a sufficient time. 

Before this i'm curious how was the chemical evolution have been induced to occurred? Beside the theory of the fallen comets, it is actually about the prebiotics broth hypothesis that have been proved by Miller-Urey's experiment.

They found that micro molecules like simple amino acid monomers formed at the end of the reaction. Examples, monosaccharides and glycerol + fatty acid. 

CHEMICAL EVOLUTION (PREBIOTICS BROTH HYPOTHESIS)

INORGANIC MOLECULES

                  

         ↓                                   
MONOMERS ORGANIC – SIMPLE ORGANIC         

            ↓                                                              

POLYMERS ORGANIC

Moreover, i like the quite confusing and interesting question for this topic. 

"Can you all guess which came out first, RNA or DNA?"

By referring to this website; 

http://www.science-explained.com/theory/dna-rna-and-protein/ 

It's clearly stated that: 

RNA is synthesized from DNA strands and from a single RNA strand also can be formed DNA strands. Closely like question that never have the exactly true answer so far. 

"Which came out first, egg or chicken?" 

It's confusing right? Well, but between RNA and DNA it is actually RNA did came first in early earth. From the website Exploring Life's Origin;

http://exploringorigins.org/nucleicacids.html

  I find out that the reason is relevant and acceptable which is evolution. At the first beginning, RNA evolved to become DNA because DNA is more stable compared to RNA (not fittest to survive).  The replication of RNA also do not need the help of enzyme, it can be replicated by itself. While DNA replication need the help of enzyme. RNA is actually ribozymes. If DNA need the help of enzyme to replicate, it can be said that RNA must be existed first, right? However, it is sad to say I still couldn't find the answer for which came first either egg or chicken.

  Overall, I think this topic is much related to the first topic which evolution. Because most of the life have been through several stages or evolution. For example the essential part of living thing which is DNA. DNA itself have been through evolution.



Cheers,
Nurul Syafiqah Azhar-published on 260915;0841pm