Unit 8 Reflection

This unit relates to these blog posts
Hunger Games lab
Bird Beak Lab
In Unit 8, we learned about the constant change in our world. It includes the gradual change over time, natural change, gene pool, speciation, structural evidence of evolution, evolution in populations, and the origin of life. We have also done some fun labs during this unit. The gradual change over time includes variation which is any difference in traits within a population and exists because of meiosis, mutations and sex cross over. Artificial selection occurs in the gradual changes as it occurs when humans select a certain trait from a certain population that they want and mate individuals with the certain trait that was chosen. This results in species changing over time and a new breed is created. Natural change is about Charles Darwin's observations and conclusions. He discovered that evolution is caused by natural selection.
He made 4 observations about evolution that is caused by natural selection. The observations are that all species that sexual reproduce have a high genetic variation in traits, traits are inherited from parents to offspring, all species are capable of producing more offspring that the environment can suppor
t, and competition is stiff. The conclusions he made were that there are winners and losers and populations are the winners. In swimming in the gene pool, it's about the total of all alleles in a population. It includes genetic variation, and change in gene pool when allele combination when individuals of the population have offspring. Allele frequencies measures genetic variation. Allele frequency is how common an allele is in a population and can be calculated for each allele in a gene pool. The steps for determining the allele frequency is adding up the total for all alleles, adding up the total for each type of alleles, and dividing the number by its total. Natural selection in a gene pool favors on a certain phenotype. The better phenotypes survive and reproduce. Winners pass on their alleles to their offspring. Also, lethal alleles stick around. If they are recessive, they will stick around and can be beneficial if condition changes.
          Speciation is about how species form. It is the rise of two or more species from an existing specie. It's caused when a population is split into two and eventually the two populations cannot reproduce. There are many causes of speciation which include behavioral, geographic, and temporal isolation. These can cause speciation to occur depending on its behaviors, geographic location, and timing of speciation. Speciation over time can cause new species to rise and can have common ancestors. The decendents have common traits that are given to the new species. There are two patterns of speciation which include graudualism,
and punctuated equilibrium. Gradualism occurs slowly, but new species arise. In punctuated equilibrium, new species rise suddenly as speciation occurs quickly due to sudden reproductive isolation. In structural evidence, there are many types of evidence that relate to evolution. It includes developmental evidence which includes embryology, which studies similar stages of embryo development, and evo devo which is the study of evolution in a developmental process. Another type of evidence is vestigial structures which is when evolution has leftovers and adaptation are benefit ancestors and are no longer needed in decendants. Another good type of evidence is fossils which can show change over time. Index fossils are species that are understood well and used for comparison. There are also many types of structures that relate to the body parts in a specie. In evolving populations there are many types of change that changes natural selection. They are directional selection, stabilizing selection, and disruptive selection. Another type of change includes genetic drift which is when a random event changes a population and results in a change in allele frequency, gene flow which moves alleles from one population to another, mutations, which produce new genetic variation that natural selection can act on, sexual selection, which selects certain traits to give to other species to improve mating success, and natural selection which selects traits that gives an advantage for survival. In the origin of life,it shows how life is formed. It's shown by abiotic synthesis or small organic molecules, joining them, forming macromolecules, packaging molecules into protocells, and origin of self replication molecules. It was discovered by Stanley Miller and Harold Urey when they showed that abiotic synthesis of organic molecules in reducing atmosphere is possible. A geologic time scale is for breaking down time periods in a time line. There are several era in the geologic time scale that covers from the formation of Earth to now. Earth has changed rapidly throughout the years.
In this unit, we've done many labs relating to this unit. We did the hunger games lab, and the bird beak lab. The hunger games lab covered the swimming in the gene pool vodcast as we collected food and created more offspring by allele frequency. In the bird beak lab, this related to change, its all natural vodcast as it covered Darwin's observation and conclusions. In this lab, we've picked up food using different types of beaks. We would count our food after a certain time limit and determine how many offspring were made. The more food picked up, then more offspring would be made.
In this unit, I want to learn about the how the Earth has changed rapidly besides the formation of the Earth. I have been more assertive especially doing group work, but still need to improve. I am still sometimes passive and I need to speak up more than before. I need to have more eye contact when I talk to others.