Unit 8 Reflection

Unit 8 was all about evolution, how all the species, and the earth itself, have changed over time. We learned about what exactly was the definition of evolution and how it was measured. All the alleles that make up genes in population are called the gene pool. The frequency of an allele in the population is called allele frequency. Evolution is measured as a change in allele frequency in the gene pool, so all species are constantly evolving. One allele becomes more or less frequent due to natural selection. Natural selection ultimately ends up choosing the genes in individuals that are more likely to survive and reproduce, therefore, making the population look like the "winners". In the Hunger Games Lab, which was the main lab this unit, we saw the disappearance of stumpys over time. They had undesirable characteristics, and therefore did not get a chance to survive and reproduce. The pinchers, on the other hand, grew more in the population because they had the most desirable characteristic to pick up food (using their thumb and index finger).
Natural selection also works in different ways. Directional selection is when one extreme phenotype is favored.  As we saw in the bird beak lab, the tweezer beaks were favored since they were the most helpful in picking up food and soon the amount of offspring were mostly tweezer beaks. Stabilizing selection is when intermediate phenotypes are favored. Disruptive selection is when two extreme phenotypes are favored. Natural is not the only thing that causes species to evolve. Genetic drifts are random events that suddenly changes the allele frequency. This change may be either good or bad. Gene flow is the movement of alleles from one population to another. Mutations can cause a change in DNA, and if desirable, will become frequent in the population. Sexual selections that improve mating success but not help the organisms survive better.
Speciation is the creation of new species. Species separate when they are reproductively isolated. This means that the two species cannot reproduce and have fertile offspring. Temporal isolation is when they reproduce at different times. Geographic isolation is when they are physically separated. This is a technique often used with dog breeders. Behavioral isolation is when they have different techniques to attract mates.
The theory of evolution is opposed, but there is evidence to support it. When all organisms are an embryo, they all look very similar. This suggests that we all share a common ancestor. We also have features that helped our ancestors or that they had, such as our tailbone which shows that we used to have tails. Some organisms have same structures with different functions (homologous). Others have different structures with the same function.
 To be more assertive this unit, I tried to voice all my opinions in all the different labs we had to do, and while voicing them, I listened to others and I compromised with them. Hopefully in the future, I will get even more assertive.
 

Geologic Timeline Reflection

In this project, we made a timeline of Earth's history to better understand when and how some major events happened on our planet. We used a strip 10 meters long to represent the 4.6 billion years of Earth's history, where 1 million years was represented by 2 mm. One very significant major event is the creation of Earth itself, which happened 4.6 billion years ago. Nothing as we know it would exist if this collision did not happen to form our planet. The increase of oxygen in the atmosphere and organisms which use oxygen for life processes which happened in the Ordovician is an important event in Earth's history. This laid the foundation for processes such as photosynthesis and respiration, which are essential. The majority of organisms today are descended from these first organisms. The extinction of the dinosaurs was a very significant event in Earth's history as well. It happened during the Mesozoic Era and gave way for mammals to dominate. This paved a way for humans and other mammals to come into existence because the dinosaurs were very dominant at the time and the smaller mammals stood no chance.

In our scale, 1 million years was represented by 2 mm. It was surprising for how much of Earth's history there was no life. Being able to see this visually represented really put so much of history into perspective for me. Before doing this timeline, I knew that the Precambrian Era was 88% of Earth's history but when we scaled our timeline accordingly, I began to really understand how significant a part of history this is, and how we are not the biggest thing out there. We are an eye's blink compared to the history of the Earth.

Humans have made up such a small part of Earth's history, and it is surprising how much they have changed the planet in such an relatively insignificant amount of time. Humans are now the dominant species, but have been around for not even a speck in terms of geologic time.

One question I have is, how significantly have humans changed the planet in the relatively small time that they have lived on it it?

Hunger Games Final Analysis

1. In this Hunger Games Lab, we ate corks using different methods including wrist, thumb/index finger, and middle finger/index finger knuckles. Those with less food died off. Those who survived mated and tossed coins to simulate sex. The offspring was given the traits. As each generation progressed, the allele frequency changed. This stimulated natural selection and a real world population of organisms trying to survive.
2. The phenotype that was the best at capturing food was the pincher phenotype. This was because the pinchers could get the corks the easiest because using your fingers is easier than using your knuckles and wrists.  
3. Our population did evolve, according to the defintition of evolution. This is because our allele frequency changed over time. The allele frequency changed from 52-48 to 31-69 to 42-58 to 39-61 to 32-68 to 27-73 40-60 from the ration A-a. This change meant that the genotype aa was more favorable, leading more of us to try and get this genotype.
4. The non-random was the equal allele frequency at the beginning. This would help us understand the drastic change more. The non-random part were the people who retained the phenotypes. For example, if a person with big jackets and big pockets were to particiapte in this lab, he/she would do better than most, no matter their phenotype. In addition, the food was scattered randomly. Some people were farther away, and some were very close. Lastly, the physical attributes of the participants also affected the outcome. Those who are larger can scoop the food and get the food in large volumes. Those who are faster can get to the jackpot or the big pile in the middle faster.
5. If the food were larger, then the pinchers would have a more difficult time, but the stumpies would actually thrive. However, the knucklers would die first If the food were smaller, then the stumpies would die off quite fast, but the pinchers would still thrive. The knucklers would have some difficulty, but would still survive. This may be found in nature if humans intervene with nature. Some small fish in the ocean may die becuase of toxic waters, whilst big fish survive.
6. If there were no incomplete dominance, then knucklers would not exist. However, the stumpys would be much more dominant, with the allele frequency being more drastic. 
7. Natural selection is the catalyst and the driving force behind evolution. Those with favorable traits are naturally selected, and the next generation begins to look like the winners.
8. Some strategies that individuals took were to mate with those with better phenotypes or those with the same phenotype. This made it so that most offspring were pinchers and knucklers. This was natural selection, becuase those with unfavorable traits cannot mate. You cannot mate if you are dead. 
9. In evolution, an individual does not evolve. Instead, the general population evolves. Natural selection acts upon both phenotype and the genotype. The new generation's genotype consists of the dominant allele and the majority of phenotypes is the dominante phenotype. In this case, it would be the pinchers,
10. My only question is if this stimulation continued for many trials, will the allele frequency ever reach a limit?

Bird Beak Lab

Hypothesis(claim)	Evidence of this occurring	Reasoning for this
Individuals with better traits leave more offspring	Tweezer beaks had more offspring Had 44% of the total offspring	The tweezers collected more food, which made more offspring
Populations begin to look more like the winners	Almost half of the new population(44%) had tweezer  beaks	Tweezers pass on their traits and make more offspring and others don’t

 In this lab we asked the question, "If natural selection occurs in a population, how do changes in selective pressures affect the evolution of that species?" Before the environment changed, we found that out of the beak types: scissors, tweezers, scissors, and a binder clip, the tweezers got the most food resulting in more offspring.The tweezers managed to pick up enough food to support 31 chicks. The next beak type that was also quite effective was the binder clip, at 19 chicks.  The worst one out of the 4, was the spoon, at 10 chicks. This confirmed Charles Darwin's conclusion that, "Individuals whose inherited  traits help them survive and reproduce more tend to leave more offspring than other individuals." However, the environment later changed, and the results were drastically different. The environment change was that we had 10 seconds to collect food instead of 30. Here, the binder clip had the most total offspring, at 16. Tweezers were close behind, at 14 chicks. The least number of chicks was different this time. It was the scissors beak, at 7 chicks. This proves that environment changes affect a population and its traits.

While our hypothesis was supported by our data, there could have been errors due to the "food" we were given. Maybe if one beak that did not get as much offspring could have had a food that they were good at collecting. However, there might not have been as much of that food. This would have caused the beak to not produce as much offspring. Next time, make sure that all the materials that are needed are present to provide the most exact data. Secondly, it would be unfair for certain players/birds because the food would be more towards others, and also because of the limited space it didn't allow us do our best. This cause some people to maybe have an a vantage because the food was closer to them. For future references,maybe make the field a bit bigger so that it is evenly spread out.

This lab was done to demonstrate natural selection and resembles the competition between the different organisms in an environment. From this lab, I learned how different features affect the lives of species. Also, this supported conclusions of Charles Darwin. This can be used to raise awareness to protect other species from these environment changes. Based on my experience from this lab, I now get a closer feeling of the competition between animals.