THIS PAGE CONTAINS EVERYTHING WE DID IN THE EVOLUTION UNIT. THIS INCLUDES COMPARATIVE ANATOMY, TRANSITIONAL SPECIES VIDEO, OUR BOOK CLUB REVIEW, SOCRATIC SEMINAR REFLECTION, AND AN OVERALL REFLECTION OF THIS WHOLE UNIT. EACH SECTION IS IN BOLD WRITING.
Comparative Anatomy
Summary
In this section we compared different species as a means to learn about evolution. We looked at different species that have evolved over millions of years. In each organism we studied, we were able to see the progressing complexity of their organs. We were able to see which animals evolved first and how they evolved to the modern humans of today. The following paragraphs include more information about each organism we learned about.
Comparative Anatomy
Summary
In this section we compared different species as a means to learn about evolution. We looked at different species that have evolved over millions of years. In each organism we studied, we were able to see the progressing complexity of their organs. We were able to see which animals evolved first and how they evolved to the modern humans of today. The following paragraphs include more information about each organism we learned about.
Pictures
Jellyfish Presentation
Ecology of Sponges
Sponges play an important part of the ecology of aquatic organisms. They have irregular shapes, which makes them suitable habitats for marine animals. Sponges also have a close relationship with bacteria, algae, and other plantlike protists. These organisms provide food and oxygen for the sponge. In return, the sponge provides a protected area where these organisms can live. Since sponges live attached to the sea floor, they only receive low levels of sunlight. They are able to carry out photosynthesis by using their spicules to focus and direct sunlight to cells. This adaptation is important because it allows sponges to survive in a wider range of habitats.
Comparison of Cnidaria and Porifera
Sponges are colored green because organisms like bacteria, algae, or other plantlike protists are living in their tissues. Sponges eat food by extracting small organisms from the water that passes through it. They are asymmetrical and have choanocytes that are specialized cells that use flagella to move water through the sponge. Cnidaria are symmetrical. Cnidarians have cnidocytes, or stinging cells, that are around their tentacles. They use these cells for defense and to catch prey. Cnidarians are the simplest animals to have body symmetry and specialized tissues. Sponges do not have a nervous system and a simple skeleton. Digestion takes place inside their cells. Sponges rely on water to carry out their body functions. Cnidarians have two different stages: a polyp and a medusa. They have a body wall that surrounds an internal space called a gastrovascular cavity. Their digestion takes place outside of their cells. They gain information from the environment using specialized sensory cells. Sponges are multicellular, no cell walls. and contain a few specialized cells. Cnidarians are soft-bodied, carnivorous animals that have stinging tentacles.
Ecology of Corals
Corals rely on light and symbioses with algae because it helps capture solar energy, recycle nutrients, and help lay down their calcium carbonate skeletons. Coral reefs are suffering from human activity. Sometimes, recreational divers damage coral reefs. Sediments from logging, farming, mining, and construction can smother reefs. Chemical fertilizers, insecticides, and industrial pollutants can poison corals. Coral bleaching has become a problem, which consists of high temperatures killing algae that live in the tissues of corals. This has become such a problem that it is common for corals to die.
Ecology of Mollusks
Mollusks filter algae out of the water by eating detritus. Mollusks are also an important source of food for other organisms, including humans. Bacteria surrounding bivalves extract chemical energy from simple compounds released in superheated water. From this, they can produce food for Mollusks. Mollusks can be used to monitor water quality. They can also warn biologists about potential dangers in open water. They also are used for biological research.
Groups of Mollusks
One group are the Gastropods. They are shell-less and move by using a muscular foot. The second group are the Bivalves. They have two shells and are held together by muscles. The last group are the Cephalopods. They are soft-bodied and have a single head attached to a single foot.
Mollusk Comparison to Porifera, Cnidaria, and Annelida
Mollusks have a mantle, which serves as a thin layer of tissue that covers most of the body. They also have a foot and tentacle used for capturing prey. Mollusks also have a shell that is made of glands that secretes calcium carbonate. There is also the visceral mass, with contains most of the organs. Like Annelids, Mollusks have true coelom around mesoderm tissue. They also have complex organ systems. Mollusks have a radula, which is used for feeding. They also have a siphon in which water enters and leaves the body through. Aquatic Mollusks breathe through gills, while land Mollusks breathe using a mantle cavity. Mollusks have a circulatory system. It is either open or closed. Waste is released into the blood.
Groups of Annelids
The first group of Annelids are titled Oligochaetes. They generally have streamlined bodies. They also have few setae compared to polychaetes. Oligochaetes live in soil or fresh-water. The second group are called leeches. They are external parasites. Leeches suck blood and body fluids of their host. They have powerful suckers that help them stick to their host. They were once commonly used for medical purposes. The last group are called Polychaetes. They are marine Annelids. They have paired, paddlelike appendages tipped with setae.
Ecology of Annelids
Annelids, generally earthworms, spend their life burrowing through soil. The tunnels they create provide passageway for plant roots and water. Earthworms help plant matter decompose. Earthworm feces are rich in nitrogen, phosphorus, micronutrients, potassium, and beneficial bacteria. These worms are also an important part of the diet of many birds. Marine annelids are also an important part of the food chain. Some marine annelids are common in areas where sediment is disturbed. They are even more common where pollution from sewage creates bacteria and algae.
Comparison of Annelids to Cnidaria and Porifera
Annelids are worms with segmented bodies. They have a true coelom which is lined with mesoderm. They are divided into segments separated by septa which are walls between each segment. They have a digestive track that food passes through. They also have a pharynx used to attack prey. They also have a crop which is where food is stored. It is then pushed through the gizzard which grinds the food into smaller pieces. Annelids typically have a closed circulatory system. Their blood circulates through two major blood vessels that run from head to tail. Marine annelids breathe through gills while land roaming annelids breathe through their skin. Waste containing nitrogen is eliminated by nephridia. They have a well-developed nervous system which includes a brain and nerve cords. Sense organs are best evolved in marine annelids. They also have body muscles that help with moving around.
Comparison of Invertebrates and Vertebrates: How Did They Evolve
Evidence shows that the most ancient chordates were closely related to echinoderms. One of the ancient chordate fossils that scientists have found is called Pikaia. It was first thought to be a worm, but upon further inspection it was noted the organism had a notochord. Notochords are a flexible, supporting structure only found in chordates. Pikaia is considered an early chordate. A notable event in chordate evolution was the development of jaws. Another event that separated vertebrates from invertebrates was the development of paired appendages. Vertebrates evolved from invertebrates.Vertebrates make up about 96 percent of all living chordates.
Comparison of Invertebrates and Vertebrates: How do They Maintain Body Temperature
The ability to maintain body temperature is well developed among vertebrates. The ability to do this is important for maintaining homeostasis, especially where temperature varies. The control of body temperature revolves around three things: a source of heat, way to conserve heat, and a method of eliminating excess heat. These organisms can be classified as ectotherms or endotherms. Mostly reptiles, fishes, and amphibians are ectotherms. They pick up heat from their environment. An endotherm controls their body heat from within. Birds conserve heat by using their feathers as insulation. Mammals use fat to conserve heat.
Comparison of Invertebrates and Vertebrates: How do They Feed, Respire, Excrete, Circulate, Move, and Respond
The skulls and teeth of vertebrates are adapted for feeding on a wider variety of food. Many mammals have sharp teeth that they use to tear their food. Their digestive system have organs that are well adapted for different feeding habits. Aquatic chordates use gills for respiration. Land vertebrates use lungs. Animals who use gills to breathe receive their oxygen from the water. Organisms who use lungs to breathe receive their oxygen from the air. Most vertebrates use their kidneys to excrete waste. Aquatic organisms excrete their waste in the form of ammonia. Chordates who use gills for breathing have a single-loop circulatory system. Vertebrates who use lungs to breathe have a double-loop circulatory system. The chordate heart has developed chambers that help separate oxygenated and deoxygenated blood traveling in the circulatory system. Nonvertebrate chordates lack bones, but have muscles. Although, most other chordates do indeed have bones. The skeletal and muscular systems make it possible for vertebrates to move. Nonvertebrate chordates have a very simple nervous system with a mass of nerve cells that form a brain. Vertebrates have a complex brain with different regions. Each of these regions have a different function.
How Fish Feed, Respire, Circulate, Excrete, Respond, and Respire
Fishes are aquatic vertebrates that are characterized by paired fins, scales, and gills. Fish are herbivores, carnivores, parasites, filter feeders, and detritus. Fish can feed on many forms of nutrients depending upon their environment and what is available to them. Fishes have a mouth, food passes through a short esophagus to the stomach, where it is partially broken down. In many fishes the food is further processed in fingerlike pouches called pyloric. Other organs including the liver and pancreas, add enzymes and other digestive chemicals to the food as it moves through the digestive tract. The intestine completes the process of digestion and nutrient absorption. Most fish exchange gases using using gills located on either side of the pharynx. Gills are made up of feathery threadlike structures called filaments and each filament contains a network of fine capillaries that provided a large surface area for the exchange of H2O and CO2. A numerous amount of fish have an adaptation that allows them to survive in oxygen-poor water or in areas where bodies of water often dry up. Those fishes have specialized organs that serve as lungs. Fishes have a closed circulatory system with a heart that pumps blood around the body in a single loop. From the heart to the gills, from the gills to the rest of the body and beck to the heart. Like many other aquatic animals, most fish rid themselves of nitrogenous waste in the form of ammonia. Some diffuse waste through gills into the surrounding water, others are removed by kidneys, which filters waste from the blood. Fish have well-developed nervous systems organized around a brain, which has several parts. Most fish have highly developed sense organs and almost all fish that are active have well-developed eyes and color vision that is at least as good as ours. Many fish have specialized cells called chemoreceptors that are responsible for their extraordinary sense of taste and smell. Most fish move by alternately paired set of muscles on either side of the backbone.
Groups of Fish and Characteristics
There are several groups fish that make up the diverse species, they are bony fish, jawless fish, and cartilaginous fish. Jawless fish are more or less self explanatory with the lack of true teeth and jaws. Their skeletons are made of cartilage and are divided into two subclasses of lampreys and hagfish. Lampreys are filter feeders and parasites while Hagfish feed on the dead and dying and have six hearts with an open circulatory system. Sharks and cartilaginous species have skeletons made of cartilage and are usually carnivores with an absurd amount of teeth that constantly replace themselves, some sharks have up to 20,000 or more teeth in it’s life. Rays and Skates are also cartilaginous who are mainly filter feeders that are generally harmless to humans.
Bony fish have skeletons of hard bone hence the name. Almost all have fins though there are some that are not classified as ray finned fish such as the lungfish.
Ecology of Fishes
Certain fishes spend the majority of their lives in the ocean but migrate to fresh water when it is breeding time. Some examples of these fish are lampreys, sturgeons, and salmon. This type of fish are called anadromous. Salmon are born and begin their lives in rivers or streams but soon after make their way to the sea. After years in the ocean the salmon use their sense of smell to find their birthplace and lay/fertilize eggs of their own.The trip back can take up to months of travelling. Other fish are the opposite of anadromous and spend the majority of their life in freshwater but migrate to the ocean for breeding. These fish are categorized as catadromous. They can travel a great distance to the sea in order to lay their eggs. Currents take hold of the eggs and carry them to shallow waters. When the eggs mature and hatch the fish find their way into fresh water and move upstream.
Perch Dissection
Observations
- The body of the perch is in a general fish shape. The body shows adaptations for life in water since the perch has both fins and gills.
- The function of the gill rakers are used to prevent food from getting away. They are used to trap food.
- The pectoral and pelvic fins are used for steering. The dorsal fin is used to maintain balance. The caudal fin is used to propel the fish through the water.
- The scales are layered and hard. They face away from the head. They provide protection from predators and allow quick movement in water.
- The fish has two nostrils that closely resemble a human's.
- The gills have feathery like structures that have the ability to capture air molecules to make the gills an efficient respiratory system
- The lateral line acts as a sensory organ in the perch. It helps the fish detect vibrations in the surrounding water, and tell if there is danger coming.
- The endoskeleton gives the fish its basic structure and supports the body.
3. The swim bladder acts as a buoyancy tool in the fish. The fish inflates the bladder with gas to rise, it can also let out air to sink. This allows the fish too choose it’s place in the water column.
4. The luminescent skin provides a light source in the dank darkness of the deep water.
Groups of Amphibians
There are three groups of amphibians which consist of salamanders, frogs and toads, and caecilians. Salamanders are part of the order Urodela. They have long bodies and tails. They usually have four legs and are carnivores. Most live in moist areas. Frogs and toads are in the order Anura and have the ability to jump. Frogs tend to have longer legs than toads. Adult frogs and toads do not have tails. Caecilians are part of the order Apoda. They are legless that live in water or in moist areas. They feed on small invertebrates. Many have fishlike scales.
Ecology of Amphibians
Amphibians have adaptations that are used to protect them from predators. Some have colors or markings that can be used to blend into their surroundings. Others have skin glands that ooze a toxin. Amphibians that release toxin are usually bright colored to warn their enemies off. Nontoxic amphibians are also sometimes bright colored to confuse predators. This way, predators assume they are toxic and leave them alone. The amount of amphibians has decreased over the past few decades. Scientists do not know why this is happening, but they guess it has to do with environmental factors. These factors include a decreasing habitat, depletion of the ozone layer, acid rain, water pollution, fungal infections, aquatic predators, and an increasing human population.
Reflection:
One thing that went well was our ability to work together. Another thing that went well was the writing of the paragraphs. One thing that went wrong was accidentally making the wrong cut in a dissection. Another thing that went wrong was the hesitancy to dissect the animals. I learned how to dissect organisms that I had never dissected before. I could still probably improve upon my dissecting skills. We could of spent more time on the dissections to make sure we didn't make any mistakes.
Transitional Species
Summary:
In this short project we created our very own transitional species. We were told to pick two phylums/animals and create a transitional species from it. My group chose to create an animal between reptiles and mammals. We came up with "Freddy". Freddy is a warm-blooded, hairy transitional species. The purpose of this project was to express our knowledge on the evolution of species. To learn more about our creature and the environment he lived in, please watch the video below.
Video:
Book Club Review
Introduction:
For this project we had a choice of books about evolution we could choose to read. I chose to read Undeniable by Bill Nye. The review is below.
Undeniable is Undeniable (Book Review)
We read Undeniable by Bill Nye. This book is centralized around the idea that animals have evolved over the course of time. Bill Nye denies ideas of creationism, stating that they are flat out unreasonable. Nye argues his case with convincing factors that will be further discussed later on in this review. Undeniable is full of hard evidence that can convince any non-believer of the reality of evolution.
Bill Nye starts his book off with a flashback to his childhood. He says he remembers seeing bees in his backyard and wondering how they are able to fly. Nye learned later on that bees shouldn’t technically be able to fly. Turns out that their bodies are not proportional to their wings. He uses this as a segment into evolution and how organisms can evolve to become more likely to survive in their environment. Nye goes to explain the different types of selection. This included topics such as natural and artificial selection. He goes on the describe the difference saying that artificial selection is due to human interference, while natural selection is caused by an animal’s environment.
After Nye explains the bee story, he goes into a segment about creationism. He talks about his debate with Ken Ham, the representative for the creationist side of things. Nye discusses the debate and proceeds to debunk everything that Ham has to say. He says it is just plain unreasonable for the world to have been created in only six days. Nye also says that it is impossible for the planet to be only six thousand years old. Bill brings up hard evidence including things like fossils, that you can’t just dismiss as unimportant. In the debate Nye brings up the famous “Noah’s Ark” story. He states that this is completely unbelievable for it doesn’t explain how every single species could fit on a single boat or how they reached their current habitats.
Bill also talks about how he dreams of finding life on other plants such as Mars. He also talks about the tools we would need to achieve this. We can discover more about ourselves from other existing organisms from new planets if we would ever be able to conquer this great feat. He thinks humans have to be committed to finding out new things about our world and universe. He also mentions that the world would be better off if the population decreased. This would make sense, as it is logical to think that the world isn’t able to satisfy the needs of seven billion people. Nye also talks about the increasing climate change. Saying this, he sees the need for an immediate change in how we treat our environment, as humans are slowly starting to destroy our atmosphere.
This is a captivating book, though some people may disagree due to their religious beliefs. There’s no denying it, the evidence is all there. Nye gives multiple forms of evidence proving creationism to be untrue and telling how he believes evolution occurred. Some readers who believe in the aspect of creationism will argue that his evidence seems flawed or untrue, but it is backed by a plethora of other scientists, geologists, and paleontologists all working to prove that evolution has occurred and might still be occurring. We found this book to be an interesting and informative read. Undeniable is undeniable!
Socratic Seminar:
Introduction:
During this Socratic Seminar we discussed our views on creationism versus evolution. We had a group of students state their cases. Anyone who wanted to add anything to the conversation, had the opportunity to.
Reflection:
During this seminar I learned a lot more about creationism. I learned more about different stories in the bible. I also learned what was created on each of the days God created the planet. I wanted to talk more about the scientific side of things. I wish I had talked more about evolution and fossils. I also wished we talked about transitional species and how everything evolved.
Reflection on the Whole Unit:
This unit was very intriguing. We learned everything there is to know about evolution. One thing our group did well was work very efficiently. We always finished quickly and had plenty of extra time. Another thing we did well was do each project to the best of our abilities. One thing I liked was the book club. It was fun to read an evolution book and learn about someone else's take on the subject. Another thing I liked was the Socratic Seminar. It was interesting to hear people argue their case on evolution. One thing I did not like was the dissections. It was hard for me to watch people cut up animals. Another thing I didn't like was all the paragraphs we had to write. Let's face it, we wrote a whole lot during this unit. One thing my group could improve upon would be staying on task and not getting distracted. Another thing we could improve upon would be maybe spending more time on our projects, so as a group, we could make sure our projects were absolutely perfect.
Introduction:
For this project we had a choice of books about evolution we could choose to read. I chose to read Undeniable by Bill Nye. The review is below.
Undeniable is Undeniable (Book Review)
We read Undeniable by Bill Nye. This book is centralized around the idea that animals have evolved over the course of time. Bill Nye denies ideas of creationism, stating that they are flat out unreasonable. Nye argues his case with convincing factors that will be further discussed later on in this review. Undeniable is full of hard evidence that can convince any non-believer of the reality of evolution.
Bill Nye starts his book off with a flashback to his childhood. He says he remembers seeing bees in his backyard and wondering how they are able to fly. Nye learned later on that bees shouldn’t technically be able to fly. Turns out that their bodies are not proportional to their wings. He uses this as a segment into evolution and how organisms can evolve to become more likely to survive in their environment. Nye goes to explain the different types of selection. This included topics such as natural and artificial selection. He goes on the describe the difference saying that artificial selection is due to human interference, while natural selection is caused by an animal’s environment.
After Nye explains the bee story, he goes into a segment about creationism. He talks about his debate with Ken Ham, the representative for the creationist side of things. Nye discusses the debate and proceeds to debunk everything that Ham has to say. He says it is just plain unreasonable for the world to have been created in only six days. Nye also says that it is impossible for the planet to be only six thousand years old. Bill brings up hard evidence including things like fossils, that you can’t just dismiss as unimportant. In the debate Nye brings up the famous “Noah’s Ark” story. He states that this is completely unbelievable for it doesn’t explain how every single species could fit on a single boat or how they reached their current habitats.
Bill also talks about how he dreams of finding life on other plants such as Mars. He also talks about the tools we would need to achieve this. We can discover more about ourselves from other existing organisms from new planets if we would ever be able to conquer this great feat. He thinks humans have to be committed to finding out new things about our world and universe. He also mentions that the world would be better off if the population decreased. This would make sense, as it is logical to think that the world isn’t able to satisfy the needs of seven billion people. Nye also talks about the increasing climate change. Saying this, he sees the need for an immediate change in how we treat our environment, as humans are slowly starting to destroy our atmosphere.
This is a captivating book, though some people may disagree due to their religious beliefs. There’s no denying it, the evidence is all there. Nye gives multiple forms of evidence proving creationism to be untrue and telling how he believes evolution occurred. Some readers who believe in the aspect of creationism will argue that his evidence seems flawed or untrue, but it is backed by a plethora of other scientists, geologists, and paleontologists all working to prove that evolution has occurred and might still be occurring. We found this book to be an interesting and informative read. Undeniable is undeniable!
Socratic Seminar:
Introduction:
During this Socratic Seminar we discussed our views on creationism versus evolution. We had a group of students state their cases. Anyone who wanted to add anything to the conversation, had the opportunity to.
Reflection:
During this seminar I learned a lot more about creationism. I learned more about different stories in the bible. I also learned what was created on each of the days God created the planet. I wanted to talk more about the scientific side of things. I wish I had talked more about evolution and fossils. I also wished we talked about transitional species and how everything evolved.
Reflection on the Whole Unit:
This unit was very intriguing. We learned everything there is to know about evolution. One thing our group did well was work very efficiently. We always finished quickly and had plenty of extra time. Another thing we did well was do each project to the best of our abilities. One thing I liked was the book club. It was fun to read an evolution book and learn about someone else's take on the subject. Another thing I liked was the Socratic Seminar. It was interesting to hear people argue their case on evolution. One thing I did not like was the dissections. It was hard for me to watch people cut up animals. Another thing I didn't like was all the paragraphs we had to write. Let's face it, we wrote a whole lot during this unit. One thing my group could improve upon would be staying on task and not getting distracted. Another thing we could improve upon would be maybe spending more time on our projects, so as a group, we could make sure our projects were absolutely perfect.