20 Time Final Post

My 20 Time project was about converting regular concrete into pervious concrete. I was successful in making a slab of concrete porous by spraying it with chemicals. Gypsum and vinegar were the two chemicals that worked and I have submitted my project to Google Science Fair. Over the summer, I will continue to work on my project by finding the most effective mixtures of gypsum and vinegar for use on concrete. I will also test the structural stability of treated concrete blocks.

Gypsum I tested on the concrete in an ~1/5 solution in water

The TED Talk I gave in class about my project

I would say my talk went quite well. Although I stumbled a lot at the start, once I got on track, my speaking got smoother and I was able to articulate my thoughts in a way the audience could understand. I thought I would need my notes, but I ended up just using the images as cues. That being said, I was still very nervous beforehand because I had only written the script the night before. I also had no words in my slideshow, so there were no hints to read off of without looking down at my notes.

Even though I was more nervous before this presentation than before my "What on Earth Evolved?" Presentation, I felt this one looked more professional overall. This is because I had more true passion for what I was talking about, allowing me to walk around and look relaxed. However, I may have been unclear in some parts because during the questions, some people were asking me things that I thought I had answered while talking. Overall, this was a slight improvement from my Tiktaalik presentation, but a definite improvement from my public speaking skills at the start of the year.

Unit 9 Reflection

This unit was about life and the way it's organized. Life is organized with a system of levels from general to specific. For example, there can be multiple orders in a class, and multiple classes in a phylum. Using this method, biologists can show how closely related organisms are.

At the top, there are 3 domains. These are Archaea, Bacteria, and Eukarya. Archaeans live in extreme environments like hydrothermal vents and are prokaryotes. Bacteria are very common and live almost everywhere, including inside of us. Eukarya comprises all the "advanced" organisms that tend to have larger cells, are often multicellular, and have specialized organelles.
There are many confusing kingdoms within Archaea and Bacteria, so we focused on Eukarya.
Within Eukarya, there are the kingdoms Animalia, Fungi, Plantae, and Protista. Animals are all heterotrophic and multicellular. Fungi are all heterotrophic but vary in terms of number of cells. They are made of filaments called hyphae that absorb nutrients out of the ground. Plants are all autotrophic and multicellular. They use chloroplasts to convert sunlight, water, and CO2 into sugar, water, and O2. Protista is the "miscellaneous" category where anything that doesn't fit well in the other three kingdoms goes.

Within Animalia, there is huge variety. Phylum porifera has all the sponges which are made of unspecialized tissue and grow in a variety of shapes. Phylum cnidaria includes jellyfish, corals, anemones, and hydras that all have stinging cnidocysts. Phylum platyhelminthes is the flatworms that have a one-way gut where food comes in through the mouth/anus and goes out the same way. Phylum mollusca includes the snails, clams, and squids which share their mantle, radula, complete coelom, and ctenidia. Phylum arthropoda has segmented organisms like spiders, ants, lobsters, and trilobites whose main features are the segmented body and appendages. Phylum echinodermata, which is actually quite closely related to chordata, contains animals with radial symmetry like sea stars, brittle stars, sea urchins, sea lillies, and sea cucumbers.

Phylum chordata started with animals like the modern day agnathans that don't even have jaws. They slowly evolved jaws and other characteristics that allowed them to become more predatory. This resulted in Chondricthyes, the cartilagenous fish, and Osteicthyes, the bony fish, being formed. Osteicthyes is divided into Actinopterygii, the ray-finned fish, and Sarcopterygii, the lobe finned fish.

My "What on Earth Evolved?" Presentation on Tiktaalik

Ancestors of modern lobe finned fish like Pandericthys gave rise to the first tetrapods. These were amphibious creatures like Tiktaalik and Icthyostega. You can learn more about how they discovered a beautiful Tiktaalik fossil at this blogpost. Soon, the sauropsids and synapsids diverged. Synapsids became modern day mammals, while sauropsids became dinosaurs, lizards & snakes, turtles, crocodilians, tuataras and birds.

I want to learn more about the classification of birds, mammals, and snakes. I want to be able to identify the majority of common snakes and lizards as well as hopefully birds. I also wonder about better ways of classifying the organisms in Protista and would like to standardize and introduce those into state standards.


My "What on Earth Evolved?" presentation went extremely well. The prezi took me only about two hours to make and it looked really nice. I think the information on it was quite concise and the images helped show my point. Also, I only read through my presentation a few times beforehand in my mind, but still did amazing in class (I got more than a 100%). Because I was so passionate about this topic, I truly didn't have to do any memorization. I just used the bullet points as ideas for what to talk about and then elaborated.

For my upcoming TED talk, I will use prezi again because of its versatility and beauty. I will minimize the words on my slideshow to challenge myself to memorize all the main points. But overall, I actually think the TED talk will be easier. This is because I am going to talk about my experience with 20 Time, and talking about interesting things I've done has always been fun and easy for me. For the TED Talk, I will try to keep the confident and engaging tone that I used in my Tiktaalik presentation.

My Inner Fish

"Your Inner Fish" was a video series about evolution and how long it has taken for humans to evolve on this planet. We first watched part 1, which talks about the transition from water to land. We learned about Tiktaalik, a transitional organism that scientists think is the ancestor of all tetrapods. It also showed how the human hand evolved and its relation to structures in other tetrapods. This links back to the evolution unit and homologous structures because our palms & fingers are descended from Tiktaalik's flipper-hands. 

The second video was called "Your Inner Reptile", which was about synapsids and the transition from ancient reptiles to mammals. We learned about the ancestors of mammals and how their lifestyle involved living underground, hunting/foraging during night, hiding from dinosaurs, using whiskers as a sensory organ. It also explained the master gene "EDA" which controls all the integumentary organs including hair, nails, and glands. This relates to Unit 5 because the gene EDA causes proteins to be produced and determines the location of growth for many organs.

Q7. What was the "needle in the haystack" that they were looking for in the Canadian fossils? Why was it important?

They were looking for a transitional tetrapod fossil. The organism would have to fill the gap between lobe-finned fish and the early amphibian Icthyostega. It should have an about equal amount of fish and tetrapod characteristics to be the "needle" they are looking for. The reason it is so hard to find is because the chance of an organism from almost 400 million years ago fossilizing is very low and even if you find a specimen, the chance of it being well-preserved is miniscule. Plus, the weather is pretty harsh and they don't have much time. However, you could consider it easy to find because the team was able to narrow the location down to a relatively small area.

An extremely well fossilized Tiktaalik specimen

https://upload.wikimedia.org/wikipedia/commons/f/fa/Tiktaalik_Chicago.JPG

Q24. How and why did hair first evolve?

We think hair first evolved as a sensory organ in early mammals. They would have been similar to modern whiskers, except the rest of the body was just covered in bare skin or scales. But that makes me wonder what did they actually have on the rest of their body? Did they just have bare skin or did they have scales? If they had bare skin, then did mutations in the EDA gene cause whiskers to spread through the rest of their body? If they had scales, then wouldn't the scales have evolved into hairs because they are both keratinous structures? Although both ideas may involve EDA, the first one says that whiskers spread through the body and became hair, while the second posits that the body scales evolved into modern fur. If this were the case, then wouldn't the theory that early synapsids had whiskers become irrelevant to the development of modern hair?

Flatworm Penis Fighting

Flatworms are organisms that are part of the phylum Platyhelminthes. Flatworms are soft-bodied sea creatures that don't have segments and are bilaterally symmetrical. They are more advanced than Cnidarians due to their digestive tract, but less advanced than Molluscs because flatworms only have a one-way gastric passage.

One really cool thing about flatworms are their penis fights. They are hermaphrodites, meaning each one produces both sperm and egg. When two flatworms find each other, they start a "penis fencing" duel. Each worm has to try and stab the other with its penis and the worm that is inseminated becomes the mother. Alternatively, both worms stab each other with their penises and inseminate one another. This process is known as bilateral sperm transfer and results in both worms giving birth. When the sperm exits the male's penis, it enters the haemocoel of the other worm. The haemocoel is a blood filled cavity in platyhelminths that works as their open circulatory system.

Sources:
https://en.wikipedia.org/wiki/Flatworm
https://en.wikipedia.org/wiki/Penis_fencing
https://upload.wikimedia.org/wikipedia/commons/2/2b/Mating_Pseudobiceros_bedfordi.png

Unit 8 Reflection

This unit was about evolution and how it occurs.  Evolution is a process where mutations that are favorable for an environment become more common. This happens because organisms with favorable mutations are more likely to reproduce. We know that natural selection has occurred if there is an overall shift in the allele frequency of a population.

 In this picture, a form of selection that favors one extreme of a trait over medial and the other extreme. For example, if large claws helped a lion survive, then directional selection could occur and make large claws a common trait.

Another way we can know evolution has occurred and whether two species have a common ancestor is by looking for homologous structures. These are structures like bat wings and whale fins that have different functions but came from a common ancestor's structure.

Evolution takes place over long periods of time. The earth has been around for 4.6 billion years and basic life didn't pop up until 3.8 BYA. During the Cambrian explosion, 542 MYA, most eukaryotic phylums that we are familiar with popped up. After this event, we have a mostly clear fossil record through which we can trace evolutionary paths. What is really surprising is that H. Sapiens Sapiens only evolved 200,000 years ago. This is a blink-of-an-eye ago in geologic terms, meaning that we aren't as significant as we like to think of ourselves as.

I want to learn more about the relationship between the different ways of speciation and natural selection because it is not completely clear to me yet. I'm very interested in the classification of organisms so I want to find out more about phylogenetics.

In my Unit 7 reflection, I talked about being assertive. The survey found that assertiveness is my dominant trait and aggressiveness is strong as well. In the geologic timeline project, I have been very assertive and made sure that things got done in the best & most efficient way possible.  However, I was also quite aggressive in convincing my groupmates to do what I thought was best. I was conscious of my words and actions, which allowed me to only use aggression when trying to get something done. In my next group project, I will try to be more accepting of my teammates' thoughts and ideas.

Geologic Timeline Individual Reflection

The first major event in Earth's history is its formation. The Earth formed around 4.6 billion years ago as a magma ball that was constantly being pummeled by meteors. Slowly, it cooled down and developed a carbon dioxide atmosphere that protected the surface from celestial objects. The formation is very significant because without it, there would be no place for life to develop in our solar system.
Another important event is the Great Oxygenation Event. The event occurred around 2.3 billion years ago because of the appearance of Cyanobacteria that converted carbon dioxide into oxygen. It is a vital event because it allowed aerobic organisms to evolve and all multicellular life depends on oxygen for survival.
A huge event in the history of our planet is the Industrial Revolution. The Industrial Revolution started about 200 years ago and created a shift from mostly manual, cottage-industry style companies to concentrated, urbanized factories that depended on fossil fuels for power. The event in part lead to our current global society and materialistic, unsustainable lives. If the industrial revolution didn't occur, we may not be as technologically advanced, but we also wouldn't be seeing spikes in CO2 levels, temperature fluctuations, extreme weather events, microplastics in our oceans, and colossal extinction rates.

The Earth's history stretches from 4.6 billion years ago to today. If we compressed the 13.8 billion years that the universe has existed into 365 days, all human history would take place in the last few seconds of the last day of December. Although I knew the geologic time scale very well before this, I had never come across this comparison. The comparison shows how small and insignificant we are as well as how many millions of years of evolution it has taken for us to develop.

In our short time on Earth, humans have caused extinctions, elevated CO2 levels, climate change, and plastic to become extremely common. I think that by devastating our environment, we are being unfair to both our ancestors and our descendants. We are being unfair to our ancestors by harming other species which we are actually quite closely related to and destroying the planet that they contributed so much energy to. Environmental issues are very detrimental to our descendants because they will have to live in a barren world and deal with the consequences of our materialism.

Hunger Games Lab

1. In this lab, we assigned people to certain types of feeding patterns. People with the AA genotype had to pick up food (corks) with their wrists, Aa had to use their second knuckles, and aa had to use their fingers. Each round, each individual would need to have eaten a certain amount of food to reproduce and survive. If the survive, they find a mate and flip coins to choose their baby's genotype. As the experiment goes on, favorable traits reproduce more and the allele frequency changes. The experiment simulated how natural selection occurs and put together the concepts of mendelian genetics and survival of the fittest.

2. The data shows that the knucklers were the best at capturing food. However, this is most likely a result of cheating because many of the knucklers used their entire hands rather than just their knuckles.

3. The population definitely evolved. At the start, 48% of the population had "a" alleles and 52% had "A" alleles. This was pretty even and the allele frequency was very balanced at the start. However, by the end of the 8th trial, the "a" had a staggering 70% frequency while "A" only had a frequency of 30%. If evolution is a change in allele frequency over time, then a change of this scale is definitely evidence that natural selection took place.

 4. In this lab, there was a lot of other factors that affected results. Some people didn't have pockets which prevented them from gathering much food. Others weren't very fast at running or picking the corks up which prevented them from getting to the food. Many participants also cheated by not using their assigned phenotype, which allowed them to unfairly sway the results in their phenotype's favor.

5. If food was larger, then disruptive selection may take place. This is because the stumpies would be able to pick it up with their palms and the pinchers could grasp around the food with their long fingers. But the knucklers, whose phalanges can't stretch that far apart, would die off. If the corks were smaller, I would expect directional selection in which the knucklers and pinchers are favored due to their better dexterity.

6. Yes. If one allele had complete dominance over the other, then the pinchers might have become extremely rare. This would doom the population to being outcompeted by other species because only the inefficient knucklers would be common.

7. Natural selection is the mechanism, while evolution is the actual change that results from the shift in allele frequency.

8. The pinchers tended to mate with other pinchers because we knew that the "aa" phenotype tended to survive better. Also, the stumpies would try to mate with knucklers or pinchers because that would allow their child to be a knuckler. If mating choice was random, knucklers would easily become the majority phenotype.

9. In evolution, the population evolves. Natural selection acts on phenotypes, but as a result the genotype frequency changes. For example, if black fur helps with camouflage, then natural selection will cause the black fur trait to become common. But various genotypes can cause black fur and natural selection does not discriminate between those.