Geologic Time Line Reflection

Three major events in Earth's history is when the colonization of plants and animals happened, when the dinosaurs were abundant, and the ice age. The first few periods were a lot longer compared to the rest of the periods combined. We have evolved a lot and done so much on our planet. I don't have any questions that I can think of at the moment. 

Unit 8 Reflection

In this unit we learned about what evolution . Variation exists everywhere and is only a difference in traits within a population. The gene pool is the total of all alleles in a population for a trait. Gene pools change as new allele combinations form when individuals of the population have offspring. The winners pass on their alleles to their offspring. A species is a group of individuals that can reproduce and have fertile offspring. Behavioral isolation is caused by changed in courtship or mating. behaviors or occupying different niches. Embryology is where similar stages of embryo development suggests common ancestry. Hox genes are responsible for turning on other genes during development. Index fossils are species that are understood well and used for comparison. Homologous structures have the same structures but have different functions which shows common ancestry. Analogous structures have the same function but different structures. It's not individuals that evolve, but the species that do. Natural selection can change the distribution of a trait in three ways, directional selection, stabilizing selection, and disruptive selection. Directional selection favor phenotypes at one extreme. Stabilizing selection favors both extreme phenotypes. Disruptive selection favors both extreme phenotypes. Genetic drift is when a random event drastically changes a population and results in change in allele frequency. Adaptive Radiation is when there is rapid speciation from a common ancestor. As demonstrated in the Hunger Games Lab, we simulated a real world population and we saw how the different species "evolved".





Homologous structures:
       



Analogous structures:      

Hunger Games Lab

1. In this lab, we simulated a real world population. There were three different genotypes. There were pinchers, knucklers, and stumpees. The pinchers and the knucklers had an advantage over the stumpees. 
2. The pinchers were the best at catching food because they could pick up the food the easiest with the least effort. 
3. Our population evolved, at first there were nine stumpees, but at the end there were only one or two.
4. How the stumpees had a disadvantage wasn't random. The way that certain people picked up food was random. Some people were better at picking up food that others. There was also that kuncklers seemed to only want to mate with knucklers so that affected the population as well 
5. If there was more food, the results might have been different. The stumpees would have more to gather before the others took them, and more of them might have survived
6. The results would have been different if there wasn't complete dominance.The stumpees would have probably all died out and only the pinchers would have survived. There wouldn't have been any knuckers. 
7. Natural selection is what causes evolution. Only the best traits survive and are passed on.
8. The way certain people picked up food, helped them survive. One person, used their hood to gather food, which made it a lot easier. This might have helped the knuckler population, which was why it remained really high. 

BIG IDEA: Only the best evolves. Natural selection acts on the phenotype. It selects if the phenotype makes it possible to survive, and then it gets passed on.

corks were used as "food"

Bird Beak Lab

We did a Bird Beak lab, where we tested to see which beak could get more offspring. We used tweezers, a binder clip, and scissors to mimic the different beak types. I thought that if one type of beak can pick up more food than the others, then that will overpower the others and only that species will survive. 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. We found that the tweezers, which is the most similar to the woodpecker, could get the most offspring. In the first part, the tweezers got 20 chicks , while the binder clips and scissors only got 16 and 18. This data supports our claim because eventually, the woodpecker would gain more and more offspring, until it overpowers the other birds.

While our hypothesis was supported by our data, we could have had errors due to the speed of a person. One person might be able to pick up more "food" even with a weaker beak. To eliminate these possible errors, I would recommend having the same person test with all the different types of beaks rather than having different people using different beaks. Another thing we could do to improve this experiment is to have more tests. 

The lab was done to demonstrate how natural selection works. From this lab I learned the concept of natural selection. Based on my experience from this lab, I know how evolution can happen from natural selection.