Unit 8 Reflection

In this unit, one of the first things we learned about was Darwin's research and how Evolution is caused by Natural Selection. Darwin had 4 observations: All sexually reproducing species has variation, traits are inherited, all species have capacity to grow over limits, and that there are lots of competition (two types being - introspecific, which is competition between same species, and interspecific, competition between different species. From these observations he concluded with 2 conclusions: the first one being that in the natural world there are winners and losers; he second conclusions was that in the end population usually looks like winners because of natural selection, a process of weeding out traits in a population that do not help individuals survive. So, because of natural selection: traits that are neutral or DO help an individual survive will be passed on. With natural selection comes change and in the gene pool there is constant change. The gene pool is the total of all the alleles, which are different variations of a gene that give different variations of that trait, in a population. Hence, genetic variations is stored in the gene pool and the pools change as new allele combinations form when individuals of the population give birth to offspring. In order to measure the genetic variation, the allele frequency needs to be measured. The allele frequency is how common an allele is in a  population. Though the beneficial and "good" alleles are passed on to offspring there are non-beneficial alleles that stick around called lethal alleles. If recessive, lethal alleles, can stay hidden in a population in heterozygotes, and then can be passed one when two creatures with the recessive lethal allele mate will have offspring that contain that allele. Natural selection results in evolution and in evolution there is speciation, the rise of 2 ore more species from 1 existing species. Without isolation there cannot be speciation and that is why speciation is caused by reproductive isolation, when a population is split into 2 and eventually the 2 populations can't reproduce with one another. There are 3 different causes of speciation. The first cause is called behavioral isolation which is caused by changes in courtship (mating behaviors or occupying different niches). The second cause is geographic isolation, which is when some kind of physcial divides the species into groups. And finally the third cause is temporal isolation which is when timing prevents reproduction between populations. With the different causes of speciation comes the two different patterns of it. There is gradualism which is when speciation occurs slowly but over many generations and there is punctuated equilibrium which is when new species arise "suddenly" and extremely fast. There are evidences of evolution, one of them being fossils. Natural selection can change a distribution of traits in one of 3 ways: Directional selection, stabilizing selection, and disruptive selection. On Earth, life may have formed through chemical and physical processes on early Earth that may have produced very simple cells through sequences of stages that result in the origin of self-replicating molecules. There are 3 main eras in history: the Precambrian Era, the Paleozoic Era, the Mesozoic Era, and finally the Cenozoic Era. Each of these Eras have periods in them where mass extinction and development of the world occurred (evolution).

I would like to learn more about how exactly the development of humans shaped the world. Thus my questions is: How exactly did the development of humans affect Earth?

In order to be more assertive and less aggressive when I'm under stress now I try not to speak too much because when I do speak I tend to say not so nice things to people. I'm also being more direct and speaking up more. For me, in terms of this, I still need to work on how aggressive I am when I'm under stress, I think for this I'll probably ask my peers or research on what I can do in order to stay calm during stress.

Geologic Timeline Individual Reflection

There have been a lot of major events in Earth, but 3 stand out to me. The first event that stands out to me is the large extinction that occurred during the Permian era. This extinction wiped out many marine communities and created many niches, one of them being land, that helped the dinosaurs survive. This event is significant because if this extinction had not happen then Earth would've been still covered with marine life and would have barely any niche that would help us survive. The second one is the "Cambrian Explosion" that happened during the Cambrian Era. In this explosion, the diversification of life boosted throughout Earth, in a small amount of time, only about 40 million years. This explosion is significant because it resulted in new species and wide diversity. The third event that stands out to me is the mass extinction of the dinosaurs that occurred in the Mesozoic Era. The dinosaurs were all wiped out and this is significant because if they had not been wiped out, then humans would not have been able to dominate the food chain and perspire as we have, due to dinosaurs ultimately being the more powerful creatures when compared to humans and mammals.

The scale of Earth's history is massive, taking it a long time to grow into what it is now. Most of it is the Precambrian Era and about 542 million years ago was the Paleozoic Era, in which the oldest creatures existed. Also, about 251 million years ago, there was the Paleozoic Era, where the existence of many plants and animals started. There is also the Mesozoic Era, about 65.5 million years ago, and the Cenozoic Era, which is an ongoing era that started 65.5 million years ago. What surprised me is how recent Earth started developing and having life and diversity.

To us it seems like we've made a big impact on Earth with our technology and our creations but really we are just a very small part of Earth's history; we are merely a speck. Though we are just a speck, I feel as if we are a very important speck because of how we've used Earth's natural resources to our benefit to the point that we're ruining it (global warming, pollution, etc.). We are a little part of Earth's timeline but we have been impacting it a lot, changing it's natural flow with our creations. 

My question is what would Earth specifically been like if dinosaurs were still alive and haven't been wiped out?

Hunger Games Lab

1. In this lab, we simulated a real world population of organisms trying to survive. All of us split into 3 phenotypes, each of us had 3 pennies labeled front and back based on 3 genotypes (AA, Aa, aa). There were 50 - 100 pieces of food and we were given trials of 30 seconds of feeding to collect as much food as we could through the method we were given (our phenotype: Stumpys, can only pick up food with wrists, Knucklers, can only pick up food between the second knuckles of index and middle fingers, and Pinchers, can only pick up food between thumb and index finger). No more than half of us could survive, we were eliminated by the number of food we collected. Those dead would move to the perimeter and the survivors would find a mate. They would choose a mate that they think would be good at getting food, and then they would each flip a coin to determine the genotype of the offspring. The dead people would then come in to represent the new generation and the different type of species (Knucklers, Stumpys, and Pinchers). All of us would then record the number of each genotype. This whole cycle would then repeat 7 more times.

2. The phenotype that was the best at capturing food were the Pinchers due to their phenotype being an advantage over the other species. The Pinchers got to pick up the food through their thumb and index finger, which compared to the other phenotypes was the easiest way to pick up food quickly.

3. The population did evolve because in the first trial the population size was 23, having 8 Stumpys, 8 Knucklers, and 7 Pinchers, but than in the last trial the population size was down to 15, having 0 Stumpys, 9 Knucklers, and 6 Pinchers. This shows how the overall population size decreased, meaning that the population did in fact evolve.

4. In this lab, the things that were random were how the food was placed on the field. Sometimes it was all evenly spread out, sometimes there were more at one part of the field, and other times it was all piled up in the center. This affected the evolution of the population because if there was more on part of the field than whichever species that were closest to the food would perspire. And if it was all evenly spread out or it was all piled up in the center, whichever species that was the fastest and had the most advantageous phenotype would live on and give birth to offspring.

5. The results would have been definitely different if the food was larger or smaller. If the food was larger than it could've been harder to collect so the species would've been unable to collect enough food and the population would decrease. If the food was smaller than it could've been easier to collect so species would be able to pick up food more easily which could lead to the population rising.

6. If there was no incomplete dominance then the results would've been different because in this case, if there were 0 Knucklers, than the Stumpys would die, resulting in Pinchers being able to collect the most food. If the Pinchers collect the most food than they'll have offspring but the offspring will have to go against each other for food since all the other species have already died out, which is harder thus the population decreasing.

7. Evolution is the result of natural selection. Natural selection eliminates species with worse traits and give species with better traits the chance to expand their population through offspring and this leads to evolution because once this process happens the population begins to look more like winners; and evolution is the change in allele frequency over time.

8. Strategies that group of people adopt in order to increase their likelihood of survival and reproduction is that species of the same kind would work together and team up in order to have their specific population size increase, as well as survive. This would result in their specific allele frequency in the population to increase. In nature, this is also what happens, species of the same kind team up together in order to beat other species so that the species themselves can survive and reproduce.

9. In evolution, the whole population size evolves due to natural selection. Natural selection acts on both genotype and phenotype since it changes both the appearance and genetic makeup of an animal over time. When the process of natural selection happens. those with better phenotype, caused by the genotype, survive and reproduce, looking like the winners of a population.

- A question I still have is how would the world have been like if there was no natural selection, thus evolution. Would every species just keep staying the same since none are changing?


Graph:

Bird Beak Lab

1.Graphs:

Part 1 Analysis:

Claim/hypothesis: 

"Individual with better traits leave more offspring."

 My group and I did a experiment using different kind of utensils, that resembled and represented different kinds of beak of birds, to test which beak would collect the most "food" (Macaroni "seeds", Paper clips "seeds", Rubber bands "leaves", and Toothpicks "seed pods"), thus have more offspring. We had three different trials and in the end we got our results. The tweezers beak bird had a total of 25 chicks, the scissors beak bird 14, the binder clip beak bird 18, and the spoon beak bird 9. This supports the claim because it shows how individuals with better traits, in this case the tweezers beak bird and binder clip beak bird, do produce more offspring than individuals with worse traits, the scissor beak bird and the spoon beak bird. The tweezers beak bird and binder clip bird would produce more offspring than the scissor beak bird and the spoon beak bird because they collect more food, with the help of their better traits, which means that they could have more chicks to feed that extra amount of food to. 

"Populations begin to look more like the winners."

From the experiment described in the first CER paragraph, we collected data showing how out of 100% (the population), from the order of individuals with better traits (the winners) to ones with worse traits (the losers), the percentage of chicks in the population from the different beak birds were: the tweezers beak bird boasting 37.9%, the binder clip beak bird with 27.3%, the scissor beak bird with 21.2%, and lastly, the spoon beak bird with only 13.6%. This supports the claim that populations begin to look more like the winners because it shows how out of the whole population (100%) the birds that covered it more were the birds that had won (have better traits, therefore collect more food, thus have more offspring), in this case the tweezers beak bird and the binder clip beak bird, each covering more than 1/4 of the population. 

Part 2 Conclusion:

The question of this lab was: "If natural selection occurs in a population, how do changes in selective pressures affect the evolution of that species?" To that question, my hypothesis is: If a famine hits in the area and in order to survive there needs to be 10 items of food for each offspring, then there will be less offspring overall. My group and I carried out the experiment again, getting new results. Overall there were less offspring, this time instead of having a total of 66 offspring like how before the famine hit, there were only 29 chicks. This supports my claim of there being less offspring overall because my evidence shows how the number of chicks decreased drastically, lessening more than half. The number of chicks overall probably decreased so much because the amount of food needed in order to survive increased and this makes the competition between the different beak birds harder, thus the result of less chicks for each bird (since there is now technically less food for every bird).

An error that could've occur in this lab is the miscount of rubber band "leaves" for the scissors beak bird due to them cutting some of the bands in half (or even more), resulting in them having twice (or more) the actual "leaves" they have. To minimize this error, thicker rubber bands can be used, making it harder for the scissors beak to accidentally cut them. A second error that could've occur in this lab is miscounting of the amount of food. Anyone could've easily accidentally skipped a number or two when counting their amount of food and this could've have lead to them writing down that they have more chicks than they actually do. To minimize this error, when doing this process students can slowly and quietly (in order to not be a distraction to others also counting) count two times, in order to make sure that their number's correct.

The purpose of this lab is to help us understand what Mr.Orre taught us in the vodcasts: Darwin's 4 observations and how natural selection causes evolution. Natural selection causing evolution occurs everywhere in our lives constantly, including in our own human race. As each generation of humans pass by, it is said that we get more and more attractive overall. This is so because those already attractive attract others that are also attractive, leading to them both mating and birthing a child that have their attractive traits.