Unit 8 Reflection

Unit 8, "Constant Change", was about how Earth and all its organisms have changed over time. WE learned that variation exists everywhere. Artificial selection and natural selection both eliminate traits in a populations and result in evolution, which is the change of allele frequency in a population. To see how evolution works, we did a lab called the Bird Beak Lab and we saw how natural selection acts on a population and how certain traits can be more favorable than others. All species are constantly evolving because allele frequencies are constantly changing. We learned that speciation happens when two species arise from one already existing species and results from reproductive isolation. In the Hunger Games Lab, we took a little field trip out to the field to simulate many generations of birds with different phenotypes. The lab demonstrated evolution because allele frequency changed over time.

Hunger Games Lab allele frequencies

Hunger Games lab

There are three different ways that natural selection can change the distribution of traits in a population. Directional selection is when it favors phenotypes at one extreme, stabilizing selection is when it favors the intermediate phenotype, and disruptive selection is when it favors both extremes and can sometimes lead to speciation in a population. Then, we got to learn how everything on Earth has evolved and that we all had a common ancestor. Humans have evolved over years and years. Proof of this are the vestigial structures that we have. This video shows you the vestigial structures that humans have.

Embryology suggests common ancestry

We also made a geologic timeline which showed us how small and insignificant our lives are compared to the rest of Earth's history. 88% of Earth's history didn't have much happening and only about 250 million years ago did dinosaurs walk the Earth.

Geologic timeline

For this unit, it was essential to understand that everything on Earth has changed throughout the many years. I would like to learn more about the geologic timeline and specific events that happen in each period. I'd also like to know how the Earth was created and how the first cells on Earth became organisms. I'd also like to know why land animals did not show up for a while and why organisms lived in aquatic habitats. To be more assertive, I've been working on confidence levels and the whole thing of "fake it 'til you make it" (especially because it comes in handy for color guard). For all notes and vodcasts, I've been keeping up with using colored pens so I can distinguish things from each other and help me organize it in my mind. The colors also make it easier for me to read and study.