Summer Unit 01: Biology & The Scientific Method

We begin our study of Biology with the basics; some of which is going to be review for you. Since Biology is usually defined as "the study of life," it will be helpful to understand exactly what we mean by "study" and "life." In this lesson you will review the Scientific Method as the primary tool of scientific inquiry and the characteristics that define life. 

Learning Objectives: Successful students will be able to ...

• write an essay explaining the importance of the Scientific Method as the tool that separates and defines science from other fields of inquiry such as philosophy and theology.
• list the steps of the Scientific Method and explain the specific function of each step. 
• distinguish between independent (or manipulated) variables and dependent (or responding) variables in an experiment. 
• identify and use control groups of an experiment to draw conclusions regarding the hypothesis versus the null hypothesis.
• formulate a practical and testable hypothesis to test scientific questions that have been generated by observations.
• explain how repeated support of a hypothesis leads to the development of a scientific theory and be able to distinguish between a theory and a natural law.
• list the characteristics of life with examples including possible exceptions.  

Lesson One: The Scientific Method.

Go to Kimball's Page and read the section on the Scientific Method. As you read this material be sure you understand how a hypothesis grows from careful observations. You probably have learned that a hypothesis is an "educated guess" regarding a scientific question. Appreciate that there much more to a hypothesis than a random guess about a question. Hypotheses have strict requirements of testability and reproducibility that must be met in order to make conclusions from an experiment valid. Also be aware of the use of the "null" hypothesis as a comparative alternative to the hypothesis.

Once you have read this material follow the link to the case study on contact sensitivity allergies. Pay particular attention to the logical flow of these experiments. First one experiment demonstrated the development of tolerance to contact sensitivity to a common chemical agent. Then a second experiment tested one possible hypothesis explaining this observation. Be especially careful to understand the role of the positive and negative control groups when evaluating the hypothesis.

Homework, Due 30 June: Answer the following questions and email your answers to me. You must use your Fontbonne Academy email account. I will not accept emails from any other account. No exceptions.

1. What is the difference between an empirical and a designed experiment? Is one better than the other? Explain and give examples other than those you read about in the case study.
2. What is the difference between a positive and a negative control? Explain how the two types of controls were necessary to make valid conclusions from the second experiment in the case study. 

Lesson Two: The Characteristics Of Life.

Almost every biology text has a section listing and explaining the characteristic properties that define the unique condition we call life. In other words, how do you know something is alive? Most of these are common sense observations; others not so much. Keep in mind that many non-living things share some of these defining characteristics, but none have the entire pattern of properties that characterize a living organism. Rather than sending you to a reading on this topic (Google search "characteristics of life" if you must), I am asking you to view these two videos on YouTube and decide for yourself what are the characteristics of life.

Mudskipper video from the Discovery Channel/Life series.

Homework, Due 7 July: For this assignment you must post your response directly on this page. Use the comment section below. Feel free to make more than one comment and to comment on your classmates' responses as well. 

Your comment should discuss what specific elements of the videos demonstrate at least two properties that you feel are among the characteristics of life and why you came to that conclusion. Try to identify two different characteristics for each video. You must support your comments with specific examples from the videos.

Important! When you post your comments, identify yourself only by your first name and last initial. For privacy and security reasons we don't want your full name out there in cyberspace. Please!

Additional Resources:

• OurSciencePage
• Biology Active Learner
• The Scientific Method Today  
• Online Biology Textbook, sections on the Scientific Method and Characteristics of Life 

Comments

[Nathalie P.]

In the video about the Japanese Mudskipper, two characteristics of life present include adaption and energy acquisition. The Mudskipper can easily be said to be an uncommon sight in the world of ocean fish. It can live on land and water, and can breathe air. According to the video, the mudskipper has actually been around for millions of years. It has clearly adapted very well to its environment in order for the species to defy all odds of fish never living on land. For one thing, I could clearly see that the Mudskipper has adapted cleverly well to the mud with which it gets its name from and where it calls home. The Mudskipper uses the mud to its advantage by using it for both food and protection. When danger approaches, all the Mudskipper has to do is dig itself a hole in the sand, and slither down away from predators. The Mudskipper also uses its environment to obtain food. The mud also provides the Mudskipper as a cooling tactic to protect the fish from the sun’s rays. If the Mudskipper becomes too hot, all it has to do is roll in the mud or go into its home under the surface. In addition, the physical adaptations that I noticed the Mudskipper had included its large mouth as well as its fins which appear to help the fish “walk” on land. In another movie I found about the Mudskipper, (http://www.youtube.com/watch?v=KurTiX4FDuQ), the Mudskipper’s mouth has been especially adapted to help the species dig its hole where it lives. The Mudskipper appears to suck the mud into its mouth, and spit it out in pellet-like mounds onto the mud nearby. I found it so fascinating that the Mudskipper had actually adapted to the environment like that with its mouth in order to protect itself as well as its eggs. In addition, the Mudskipper has also adapted to its land environment by evolving the use of their fins as “legs”. Throughout the movie, the Mudskipper can be seen using its fins to propel itself everywhere on the mud. The fins also help the Mudskipper to swim in the water. As a result, adaption is a characteristic of life because as seen with the Mudskipper , it helps the species live well according to its surroundings.

A second characteristic of life in the Mudskipper video is energy acquisition. In the video, the Mudskipper is seen moving along the mud in search of food. It uses its mouth which is strategically positioned at the bottom of its face to help it acquire food. As the tide goes out, it exposes broad mud flats which indicate to the Mudskipper that it is time for food. Tiny plants and animals live in the silt of the mud, which is a perfect meal for the Mudskipper. All the Mudskipper has to do, as seen in the video, is propel itself along the mud floor using its fins, and use its mouth to scoop up food from the grounds. The food in turn will provide the Mudskipper energy as it is broken down inside its body. This energy helps the Mudskipper do the daily tasks of its life such as mating, moving, sleeping, building its home, and eating some more.

[Nathalie P.]

In the video about the UCLA squirrels, the two characteristics of life present include detection and response to stimuli, and also obviously reproduction and heredity. The first characteristic I will discuss is reproduction and heredity. At first glance, the big squirrel would appear to be the baby squirrel’s mother. Hence, in order for the mother squirrel to give birth to the baby squirrel, she would have had to have found a mate around the UCLA campus, and mate with the male squirrel. Both squirrels would have conceived through sexual reproduction, and the result would be the baby squirrel seen on camera throughout the movie trying to jump over the wall. It is also known that through reproduction, DNA is passed down to the offspring in either a recessive or dominant manner. Because the baby squirrel is the offspring of the big squirrel, the mother’s DNA and hereditary traits are passed down to it. Hence, the baby squirrel is a mini replica of the mother squirrel (i.e. gray fur, busy tail, small eyes). Both squirrels therefore are the physical embodiment of reproduction and heredity, one of the characteristics of life. The mother squirrel, too, at one point was a baby, whose mother passed down her traits to it. The Cycle of Life will continue when the big squirrel seen in the video dies, and the baby squirrel will produce offspring later in its life cycle.

The second characteristic of life seen in the squirrel movie is detection and response to stimuli. All organisms respond to stimuli from their environments that can include light, temperature, odor, sound, and heat. The reaction to the stimuli is called the organism’s response. In the video, the baby squirrel approached the wall with the purpose to jump over it and follow its mother. But it had to figure out a way to jump over it first, because it was still just a baby. This response is parallel to a short term goal. The baby squirrel detected the problem (the big wall), and tried to find solutions that would help it fix the problem and help it to jump over the wall. This was transmitted to its nervous system, and being the smart creature that it is, the baby squirrel tried jumping over the wall, but failed. Another example of the detection and response to stimuli can also be seen in the simple act of the squirrels running away from the UCLA humans who tried to help them by placing bags and packages near the wall to help the baby squirrel. Both squirrels detected a disturbance in their environment with their senses (probably the sound and odor of a human), and responded to the threat by running away. Similar to Cindy’s response about a “fight or flight” reaction, the squirrels’ natural instinct is to run away. Eventually, the baby squirrel responds to the problem of the wall by using the bags offered by the students to help it to jump over. As a result, the detection and response to stimuli is another characteristic of life because it allows organisms to detect danger or obstacles in the environment, and use their nervous system in order to react.

[Callie C.]

There were two major examples of characteristics of life in the video of the baby squirrel and the bigger squirrel. The first major example was growth. The fact that the two squirrels varied in size and that the baby squirrel was the smaller one showed that the squirrels do not stay the same small size for their entire life and eventually progress in size.
The second major example of characteristics of life that the squirrels exhibited was response to stimuli. Initially, the baby squirrel was not able to jump the full height of the wall. However, the each time a new object was placed next to the wall, the baby squirrel was able to get closer to attaining its goal. Eventually, the size of the inserted stimuli was great enough that the baby squirrel was able to climb it and jump to the top of the wall. The baby squirrel positively responded to the new objects inserted by the humans.

There are two major examples of characteristics of life in the mudskipper video. The first major example is that mudskippers use energy from their environment. The mudskippers attain energy from the tiny plants and animals that they find in the mud on land. They also attain energy from the son when they bathe in the mud. The male mudskippers use the energy they attain from food and the sun to perform their high jumps and compete against other males.
The second major characteristic of life that the mudskippers exhibit is adaptation to their environment. The mudskippers were originally normal fish when they "crawled out of the ocean 365 million years ago." They needed to adapt to living on land. After 365 million years, mudskippers are now able to breathe air and crawl on land. It was necessary that they adapt because they needed the their food, which is the tiny plants and animals that reside in the mud.

[Christine C]

In the squirrel video, I found that with the many characteristics , responsiveness and interaction were the two best demonstrated. Interaction was clearly demonstrated throughout the video. As the squirrel continues to work at jumping the wall, he interacts with the people and larger squirrel who is able to jump the wall. This is an important characteristic because it shows the importance of the other animals in ones habitat and how they help to accomplish what is needed. The small squirrel is not just jumping the wall, but works with and is helped by the others. I also thought responsiveness was demonstrated. After watching the video, I concluded that responding to the given situation or obstacle is a huge part and constant action of a living animal. The wall was in front of the squirrel to jump and the bags were placed to lessen the height. Each time something new happens, or a person walked towards it, the small squirrel would respond to the given situation.
Though these characteristics were shown through the squirrel's task to jump the wall, the overall theme of responsiveness and interaction are present in all living things.
In the mudskipper video, the two characteristics I thought were clearly demonstrated, were reproduction and adaptation. Reproduction was shown during the segment about the competition to attract a mate. In the video, the mudskippers used both high jumps and wrestling to compete with each other in order to attract a mate. These competitions are not simply entertainment but an important part of their life. Attracting a mate is a vital part of life and continuation of the species. The second property I saw was adaptation. The ability to adapt to ones surroundings and environment is crucial. As the video stated, the mudskippers evolved from fish. The adapted to land with the ability to breathe air and use of the mud. As seen in the video, the creatures develops strong body parts to help maneuver their way through the mud and onto land. As the slide through the mud they scoop animals and plants into their mouths to eat and survive on. Adapting to one's environment and situation is an important part of life. In order to survive, they must successfully adapt to their surroundings.
After watching the two videos, I saw that adaptation, reproduction, interaction, responsiveness are all important properties common among living things.

[Tammy C.]

Two characteristics of living things in the squirrel video are responding and interacting to the environment. All living things respond and interact to their environment. They make changes as a response to the stimulus in their new surroundings. In the video, the baby squirrel encounters a wall that he must jump over with the other squirrel. The baby squirrel quickly learns that he is too small and weak to jump over the wall. The baby squirrel responds by trying and trying again to jump over his obstacle. The older squirrel responds to that by trying to help and show his younger companion how to jump over it. The squirrels’ responses are known as their behaviors. It based on how the squirrels respond to the new environment and working together to help each other out.
The second characteristic is interaction with the environment. Living things interact with their environment and other living things. Organisms may get energy and materials from other organisms. This is known as symbiosis. The squirrels and the humans interact with each other. The humans help the squirrels out by putting at first at backpack then more bags to assist the baby squirrel in climbing over the wall. The baby squirrel as a natural response is afraid of the humans and run quickly away. He then realizes that the bags can be used in his favor. The baby squirrel responds by climbing onto the bags and using them as a ramp to jump over the wall and join the older squirrel.
I decided on these two characteristics based on the actions of the squirrels and humans in the video. The squirrels respond to their obstacle, the wall, by attempting to jump over it. However the baby squirrel is not successful. The older squirrel tries to teach it how to jump but no matter how many times the baby squirrel tries, he is unsuccessful. The humans than interact with squirrels by assisting them by placing bags as a ramp on the wall. The baby squirrel responds by running away and responds by jumping on the bags and then successfully jumping over the wall.
The two characteristics found the Japanese Mudskipper video are adaptation and reproduction. The mudskipper is actually a fish who can also survive while being on land. The fish is able to breathe air and walk on lane in addition to swimming. It adapted to survive and exist in its muddy environment. The fish’s make up changed to be able to swim and walk and breathe in both air and water. This characteristic is an important for living things and is the reason why organisms are unique depending on where they live.
The second characteristic is reproduction. This is essential for living things to be able to continue to exist on the earth. The mudskipper males have a unique way to attract mates. They are able to stand on their front flippers and jump high into the air. This is done in order to impress the females. If that fails, the males fight each other on the muddy surface. It is important for the mudskippers to find a mate because they must continue the existence of their species.
I chose the characteristics of adaptation and reproduction for the Mudskipper video based on the fish’s actions. The mudskipper body adapted to its water and land environment. The fish is now able to breathe in air walk on land while surviving in water. It is amazing how living things evolve in order to adapt to their new surroundings. The mudskippers have a distinctive way of attracting mates. This is a natural action for all living things and is important because different species have to continue their existence.

[Rebecca S]

In the first video involving the squirrels, there were many characteristics of life that would be both easy and hard to identify. One of these characteristics was the animal’s ability to use its surroundings to its advantage. The young squirrel was faced with a challenge when it was too small to be able to jump over the wall. However, when the objects were placed in front of the wall in order to help the squirrel jump, he was able to recognize the change and use it to his advantage in order to complete the jump. This is an important characteristic of life because both animals and plants have needs and requirements to help them live that are not always easy to get or achieve. They have to be able to use their surroundings in order to survive. The second characteristic of life that I noted from the squirrel video was the interactions between the squirrel with both the other squirrel and its interesting response to the humans. The baby squirrel trusted the older the squirrel, who was trying to teach the baby the skill of jumping over the wall. However, when the humans were first helping the baby squirrel, the squirrel ran away. He was distrusting of the humans and frightened by them, which shows how life will have different interactions with creatures they view as equals as opposed to those they think could do them harm. The actions of the squirrels and the humans showed how life is codependent upon other life, for if it were not with the help of the older squirrel and the humans, the baby squirrel would not have been able to jump the wall.
The two characteristics of life in the mudskipper video that I was able to identify were adaptation and mating. Although the mudskipper is a fish, it lives on land and breathes air which is not a trait found commonly among them. The mudskipper adapts to living on land by using its benefits. It eats the small plants and animals that live in its muddy environments to survive. Also this fish has adapted the form of the fins to better navigate the land by making them more like feet and less like fins for swimming with. What is normally a fish was able to change its ways in order to be able to live on land, which shows how living creatures often need to adapt to be able to live in their environments. The second characteristic of life shown in the mudskipper video was the mating. All living species need to find some way to reproduce whether it is a plant, a wild animals, or humans. It is one of the most common characteristics of life among them all. The mudskipper males would compete with each other to gain the attention of the females as is done within many species. Mating is a very important characteristic of life because in order to stand the test of time all species must find a way to reproduce.
The characteristics of life are what distinguish organisms from inorganic materials such as rocks and minerals. The characteristics I’ve found from these two videos can all be found in humans, other animals, and plants as well because they are all necessary to their survival.

[Erin N.]

In the first video of the squirrels at the UCLA campus, the two most apparent characteristics of life seen in the squirrels actions were adaptation and response to environment. Adaptations are traits given to organisms in order for them to gain advantage in their environment, or surroundings. In adaptation, variation is important, such as the size difference between the big and little squirrel. The big squirrel had already adapted, or did not need to adapt. The little squirrel, however, was presented with a conflict when he found his size was a disadvantage in following his friend up and over the wall. At this point in the video, the life trait known as response to environment was displayed in the little squirrel. He tried to jump over the wall a few times before realizing that he was incapable. UCLA students decided to intervene, as a stimulus, causing the squirrel to react. Twice this is shown. The first reaction was to the human approach: the squirrel ran away; a negative response. The stimulus presented a possible danger to the squirrel, and so his flight response was triggered. Secondly, when the squirrel returned, he found a backpack propped up against the wall he had tirelessly attempted to overcome. The squirrel reacted positively to his new surroundings, and used the backpack, and then the pile of bags, to try and eventually jump onto the wall. The ability to adjust to the environment and respond to the stimuli show cognitive skills in the little squirrel and, as a result, life.

The second video was a short informational documentary on Japanese mudskippers. These unique fish posess the ability to transport themselves on land and breathe air. The two characteristics of life I found in the mudskippers were reproduction and the obtainment and use of energy. The mudskippers found their energy in the very mud from which they live. As their fins push them across the ground, their mouthes pick up tiny plants and animals, from which they obtain their energy source. A major portion of the video was veered towards the unusual way in which the male mudskippers attract their mates. They use the energy obtained to jump high in the air. Leaping is a contest between the men, but when that plan fails, mud wrestling takes its place. The need to attract a mate is the first step in reproduction, a necisity in life. Adaptation is also seen in this video in addition to the video of the squirrels. This characteristic of life is announced early on in the video, when the narrator explains how the mudskippers, land every other land verterbrate, crawled from the water in the very beginning of life. They adapted to their muddy surroundings by growing the organs needed to breathe air and the muscles needed to provide their fins with the strength to carry their body across the land.

These four characteristics of life, adaptation, response to environment, reproduction, and the obtainment and use of energy, are one of few specific traits that all living organisms posess. The squirrel at UCLA jumping over the wall and the japanese mudskipper jumping into the air are actions seen in everyday life, even in humans. I came to these conclusions as a result of the actions and narrations shown in the two videos, as well as additional research on the topic of life.

[KJ (Kathleen) M.]

In the squirrel video, the living things, particularly the squirrels, demonstrate the life characteristics of adaptation to the environment, growth by example, and responses to external forces or other living things. In the case of the squirrels, the squirrels were responding to their environment. They were going somewhere with a purpose, but were faced with a wall. The older squirrel reacted to this by simply jumping up and waiting for the baby squirrel to join it. The baby squirrel, however, did not know how to jump onto the wall and had to be taught. The baby squirrel was therefore dependent on the bigger squirrel to teach it to climb the wall. This interaction is similar to that of a parent with a child. In the same way a parent teaches a child to read by reading to them at bedtime each night, the bigger squirrel encouraged the baby squirrel to climb the wall by re-climbing the wall several times to show it the right way to do it. Without teachers or parents teaching children how to read, how else would they learn? Likewise, the older squirrel taught by example. This act exhibits the characteristic of growth, for the baby squirrel was growing in the older squirrel’s knowledge through their lesson of climbing. This lesson that encouraged growth, however, was not enough. The baby squirrel depended on an external force to help it, interacting with the humans. The humans taking the video decided to help the baby squirrel by first putting a backpack against the wall, which acted almost as a staircase for the baby squirrel. After first running away from this living thing, the squirrel returned to try jumping onto the wall from the backpack. When this did not work, the humans again stepped in to provide bigger bags to push against the wall. This time, the external force helped the baby squirrel to get over the wall.

Adaptation, growth, and responses to external forces or other living beings represent characteristics of life because they are relatable to most forms of life. Most living things learn from their parents or from those of their species around them. Whether they are animals or humans, life learns from those who came before. Living things also have to learn how to adapt to their environment as well as learn to deal with and react to external forces. Living things depend on each other: the squirrel depends on the human to help it get over the wall while the human depends on the squirrel to mix different plants and enrich the wild life of the human’s world. Ultimately, the squirrel video proves how life depends on other life to help keep the world in balance and shows this special symbiosis between living things.

In the mudskipper video, mudskippers demonstrate the life characteristics of reproduction and competition for survival. The male mudskipper is seen to be using the high jump to attract mates, an invitation to females to reproduce. This practice, however, is met with competition. There are other male mudskippers that want to mate with the female mudskippers. An invitation becomes a quest for survival, a quest to be the strongest male mudskipper. This leads to wrestling, a fight to be the last one to survive, which relates to the concept of adaptation. Those who are the strongest will survive and thus aptly adapt to their environment. The mudskipper must prove its strength to other mudskippers as the one to survive and ultimately the one who will adapt. This characteristic of survival contrasts with the squirrel’s and the human’s symbiosis. Instead of helping other living things, competition compels living things to defeat other life. Nevertheless, competition helps life to evolve and weed out the weak of a species; life depends on survival of the fittest.

While researching the characteristics of life, I was curious as to the definition of life, not just the characteristics, after remembering the video “Google is Alive” by Hank Green, who I follow on YouTube. (http://www.youtube.com/watch?v=etiobM3KwNc&feature=channel_video_titlehttp://www.youtube.com/watch?v=etiobM3KwNc&feature=channel_video_title). Green explains his own theory concerning the definition of life. Upon asking his followers on Twitter what they believed the definition of life to be, he received a number of characteristics: move, respire, sense, grow, reproduce, excrete, nourish. The criterion, however, do not apply to all animals. For example, a mule is the offspring of a male donkey and a female horse. Although they can move, respire, sense, grow, excrete, and nourish, the majority of mules are infertile. Green, however, argues that life can be defined simply as: life wants. Green explains, “If thing X requires thing Y in order to continue its existence and thing X shows attempts to acquire thing Y, thing X…is alive.” It’s an interesting concept. Any thoughts?

[Emma B]

The squirrel video demonstrates two characteristics of life; adaptation and interaction. These two characteristics are survival skills for all animals. The little squirrel was not able to jump over the wall and had to be taught. The big squirrel adapted to the little squirrel’s needs and attempted to teach the small squirrel how to adapt to its environment. The small squirrel became dependant on its interaction with the big squirrel. Although the assistance of the big squirrel was necessary it was not enough to achieve the survival goal of jumping over the wall. Adapting to this new environment must be accomplished by the interactions the baby squirrel with its surroundings. The addition of the human organism initiated the success of the squirrel. The backpack and the beige bags were essential to the success of the squirrel. The squirrel was able to adjust to the new environment created by the humans and jump over the wall. This entire chain of events demonstrates that survival requires successful interactions between organisms and adaptations of individual organisms.
A second example that demonstrates a response to the interactions between organisms is when the baby squirrel ran away from the humans. The squirrel did not know if the human was there to help or hurt it. The initial response to seeing a potential predator is to escape the danger. This response, although not shown in the video, is most likely taught by a bigger squirrel. These life-saving responses to potential danger are survival techniques used by all animals. This shows that the reaction to interactions between organisms is a necessary characteristic of life.
The mudskipper video exhibits adaptation and interaction but it also demonstrate reproduction. The mudskipper, being both a sea creature and land creature needs to adapt to both environments. It can breathe air and water and has strong fins that are use to maneuver around the mud. The mud skipper interacts with the different organisms in the mud in order to eat the various plants and receive the appropriate amount of nutrients to survive. Life on land is more appealing to the mudskipper because of its adaptation and interaction with the mud. Along with providing the proper food, the mud allows the animal to perform the high jump required for mating. The male mudskippers jump in the air to attract a female mate. Reproduction is an essential characteristic of life because it is what continues the life cycle to avoid extinction. Adaptation to the environment and interactions between organisms allows species to survive and reproduce. These three life characteristics are necessary for the success of organisms living together in the same environment.

[Alyssa J.]

In the squirrel video, two characteristics of life I observed were that living things respond to their environment and that living things learn from and depend on one another. The baby squirrel was dependent on the bigger squirrel to teach it how to get over the wall. The larger squirrel showed the baby many times how to jump over the wall. The baby squirrel was learning from the bigger squirrel how to maneuver through the environment, a life skill very important to squirrels. Because squirrels are always climbing up trees and over walls and fences, it was necessary for the baby to learn the jumping skill from the larger squirrel. The baby depended on the larger squirrel to learn its survival technique, and learned by example. The other characteristic of responding to the environment became evident when the bag was placed up against the wall. The squirrels took this addition to their environment and used it to their benefit in order to get the baby squirrel over the wall.

These two characteristics of life are important because animals are dependent on the older and wiser to teach them how to survive and live their lives. In the same way our parents or guardians taught us how to walk, talk, read, etc, the older squirrel teaches the baby to jump in this video. It is important for all animals to learn from those with experience. Responding to the environment is crucial as it helps the animal to survive. Often times the animal will respond to the climate and terrain in their environment. In this video, that characteristic is exhibited when the squirrels use the bag they can climb up to get to the top of the wall, rather than jumping straight up.

In the mudskipper video, the two characteristics I identified were that living things adapt to their environment and that living things need energy to survive. The mudskippers get their energy through the mud. According to the video, when the tide goes out, it exposes the mud in which, the mudskippers find plants and animals they feed on. Through their feeding on the plants and animals, the mudskippers gain their energy through food. In the same way that we as humans need to eat throughout the day to gain energy through the calories in our food to keep our bodies running, the mudskippers also need to gain this energy through their food they obtain through the mud. All living things, whether they are plants or animals, need energy for survival and will gain it through either the sun or the food they eat.

The mudskippers are also shown to have adapted to their environment. While it is a fish, it has adapted to living on land as it is able to both walk on land and breathe air. The narrator explains that the fish crawled out of the ocean millions of years ago, and then had to adapt to their environment in order to survive. It is explained in the video that life on land rather than in the ocean like most fish appealed to the mudskipper because of the mud, which is a great energy source for them. The mud also provides a place for them to perform their high jump, which the mudskippers use in mating, which will then lead to reproduction, another characteristic of living things that helps the species to continue its existence.

In these two videos, different characteristics of living things are shown through the examples of squirrels and mudskippers. The characteristics can be expanded to all living things, which need each to survive in this world. Without the ability to adapt to the environment, respond to the environment, reproduce, get energy, and depend and learn from one another, living things would not be able to survive in this world, risking complete extinction. We can relate the videos to all species, human beings, plants, insects, etc, all of which share the same characteristics of living things.

[Eliza M.]

Two characteristics of life that are present in the squirrel video include interactions and detection and response. Both the squirrels experience interactions, not only with each other but also with the humans who attempt to help the baby squirrel over the wall, the bags that help the baby squirrel get over the wall and of course, and the wall itself.
The squirrels interact with each other as the big squirrel attempts to help the baby squirrel get over the wall. The big squirrel waits for the baby squirrel even though it takes the baby a long time as well as many different efforts to eventually climb the wall. Both squirrels interact with the wall, as the big squirrel is able to jump the wall immediately while the baby squirrel makes several failed attempts to climb the wall before finally using the bags to make it to the top. The baby squirrel interacts with the bags after the humans put them there as a source of help for it. The baby squirrel uses the bags to climb the wall, which would have been too big for it otherwise. Lastly, the squirrels interact with the humans as the humans place the bags in front of the wall so as to help the baby squirrel climb the wall. Further, when the humans approach, both squirrels react by running away. In this interaction, while the humans are not afraid of the squirrels – the squirrels are frightened by their interaction with the humans causing them to run away. However, this interaction between the humans and the squirrels will ultimately result in the baby squirrels success in overcoming the obstacle of the wall.
The squirrels experienced both detection and response towards a stimulus. The first stimulus for the squirrels was a physical change in their environment: the wall. The squirrels detected the problem, the baby squirrel’s inability to make it over the wall by itself, and consequently issued a response to it. Their first responses, however not fruitful, included the big squirrel waiting at the top of the wall while the baby squirrel attempted to make it up the wall on its own. The second detection and response stemmed from the introduction of the bags into their environment. The bags also acted as a stimulus. While it took a while at first, because the squirrels initially ran away from the humans, once the squirrels detected the potential use of the bag, their response to it would ultimately end in success. The baby squirrel responded to the bags by using them as a ramp to climb the wall. The squirrels responded to the second bag, or stimulus, more quickly and successfully than the first bag, proving that they had learned from their first experience with the other bags.
In the Mudskipper video, the two characteristics of life that I believed to be the most apparent and significant are reproduction and adaptation. It was obvious in the video the ways in which the Mudskipper attracts a mate. First and foremost, the mudskipper performs a unique jump, high into the air by flinging its body around and leaping into the air. This is intended to attract female Mudskipper mates. Secondly, if necessary the Mudskipper will fight with other male Mudskippers. This attraction of a mate illustrates the vitality of finding a mate and eventually reproducing offspring. Without reproduction as an important characteristic of life, the Mudskipper would not produce offspring and as a result, would eventually be without descendents in the species, causing the species to become extinct.
Adaptation is another important characteristic of life for the Mudskipper. The most obvious form of adaptation is in the structure and makeup of the Mudskippers’ bodies. The Mudskipper is able to breathe under water like all fish can, and at the same time, has the ability to move around and breathe on land. The Mudskippers’ ability to move around on land is one that is crucial to its wellbeing and survival. The land on which it lives is covered in mud that is full of small plants and animals, which the Mudskipper lives off of. In this way, the Mudskipper adapted over time to adjust to its environment as well as its needs as an organism. It adapted to have lungs so it can breathe under water as well as breathe on land, which allows it to gain the nutrients and food that it needs from the mud on the land.
In conclusion, it is very evident through these videos that the characteristics of life are significant to the wellbeing and survival of each particular living organism. Whether it is reproduction, adaptation, interaction or detection and response, each characteristic supports both a means of survival and consequently procreation. As these characteristics aid living organisms in a means of survival, they, as a result, will cause the reproduction of any particular organism. Whether interaction is helping a baby squirrel over a wall or adaptation allows a Mudskipper to gain food from the mud on land, the characteristics of life are vital to all who breathe and live on our planet.

[Maretta M.]

I just wanted to make a quick comment about Julia's sentence "Life stems from life, and it is necessary for living things to produce more living things if life is to continue”. I think that it is fascinating that when the Mudskipper evolved, it changed not only its physical appearance, but also how it attracted a mate. It is truly amazing how creatures are able to grow and adapt to a new environment in a way that allows life to continue and flourish in future generations.

[Julia B.]

In the squirrel video, two characteristics of life I identified are dependence and survival techniques. Life is dependent on other life for its existence. This is demonstrated by the interaction between the two squirrels and the humans. Without the help of the big squirrel and the surrounding people, the baby squirrel may not have been able to reach the other side of the wall. If that were a life and death situation, the baby squirrel would owe its survival to those other living things around it. There are many other ways life depends on other life. While a rock, for example, can simply exist, living things need support from other living things for their existence. For example, plants need insects to spread pollen and worms to digest nutrients and make their soil richer. Animals consume plants or other animals as necessary sustenance, and baby animals often depend on their parent(s) for support until they are mature enough to venture out on their own. In some cases, animals survive because they live in packs all their lives and depend on the other members of the pack. This baby squirrel is an example of life because its successful existence is not possible without the support of other living things.
A second characteristic of life I observed in this video is survival techniques, which, whether physical traits or other behaviors, many living things have. In this video, the baby squirrel demonstrated repeatedly the survival technique of fight or flight. The approach of large humans triggered the reaction of the baby squirrel to run away. This is a survival technique, as the squirrel obviously cannot predict the intentions of the humans but recognizes them as a potential threat, due to their much larger size. I come to the conclusion that survival techniques are a characteristic of life because almost all living things have some trait which promotes their survival in a threatening situation. Some animals can fly, run very quickly, or strangle their foes. Some plants can poison a creature trying to consume them. The baby squirrel in this video was demonstrating his ability to flee from a potentially dangerous situation.
In the mudskipper video, two characteristics of life I noticed are adaptation and reproduction. The mudskipper is a very unique creature because it is a fish that can live on land and breathe air. This is an example of adaptation. The mudskipper evolved, through natural selection, to be capable of such feats. It adapted to its environment in order to better survive there. A valuable resource in the environment of the mudskipper is the mud, which is rich in small plants and animals. However, this resource is unavailable to fish that must remain underwater. The mudskipper is an example of adaptation because it changed in order to suit its environment. It has lungs to breathe air and muscles to move around on land, and is consequently able to obtain the benefits of the mud.
Another characteristic of life is reproduction. This video showed one step in the process of reproduction, which is finding a mate. Life stems from life, and it is necessary for living things to produce more living things if life is to continue. The mudskippers of this video practice two methods to find a mate. The first is the high jump, which is intended to be impressive and attract a female mudskipper. If this does not succeed in obtaining a mate, the males will proceed to wrestle one another. These behaviors are a very important aspect of the mudskippers’ existence and are vital to the continuation of life: if male mudskippers do not attract mates and offspring are not produced, when that generation dies they leave no successors to their species.
Overall, it is evident from these videos that many characteristics of life can be traced back to survival. Whether the organism is adapting to its environment, fleeing from or fending off a foe, or attracting a mate to reproduce offspring, characteristics of life promote the continuance of life.

[Cindy T.]

Hello Mr. Birch. This is Cindy T. I won’t be able to comment on other people’s comments because I’m going to be away until the 11th, which is also why I’m posting early.

In the squirrel video, the two characteristics of life I identified were responding to their environment and adapting to one’s environment. In the video, a backpack was placed down in front a wall the baby squirrel was trying to jump over. The baby squirrel knew from trial and error that the wall was too tall for it to jump over. It then tried to use this new object in its environment so it could jump over the wall. The backpack was then replaced with larger bags. The squirrel’s environment was changed again. The baby squirrel knew from the last time with the backpack that it could use these bags in order to jump over the wall. Finally, it was able to make it over the wall.
The squirrels also adapted to their environment. Whenever a person came over to the wall to place a bag down, the squirrel ran away. Over many years, the squirrels developed a flight response, as in “fight or flight” as a part of their natural instinct. Over the course of many years, squirrels learned to hide from larger predators in order to protect themselves. The modern day squirrel runs away when a human approaches because it sees the human as a large predator. If the human was not going to harm it intentionally, the human could harm it accidentally. Thus it learned to run and get out of the way of large animals.

In the mudskipper video, the two characteristics of life I identified were obtaining and using energy and adapting to the environment. In the video, a mudskipper is shown feeding on small plants and animals living in the mud. Mudskippers obtain their energy from food and use this energy for various activities. The video shows a few examples of these activities, such as walking across the mud, high jumping, and mud wrestling.
The mudskipper’s physical traits also show that they have adapted to their environment over time. Mudskippers eat small animals and plants that live in the mud. The mudskipper’s mouth is placed at the bottom of its head so it has easy access to the mud bed and can eat. In the video, it is also shown that their fins, the ones used for walking, are able to bend differently from a regular fish. A regular fish’s side fins move back and forth to swim. If one looks close, one can see the mudskipper’s fins bend in a way that resembles when one pushes their hand with only the top portion of the fingers at the edge of the desk and the rest of the hand off of the desk. These fins must be strong enough and flexible enough to walk and also do high jumps. The high jumps are to attract mates; the higher the jump, the more attractive the mudskipper appears. Thus through natural selection, the mudskippers that cannot jump high, and have weak fins, die off while the strong-fin gene is carried on.

I came to the conclusion that these three characteristics I have mentioned are characteristics of life because these traits help living organisms to survive. The mudskipper needs energy in order to survive and complete various functions, from simple as breathing to as complex as high jumping. The squirrel and the mudskipper also adapted to their respective environments. A mudskipper has strong fins and a mouth paced on the bottom of its head because they are best used in a muddy environment and the mudskipper needs them in order to live easily in the environment. Squirrels, over time, learned how to run and hide from larger predators in order to protect themselves. If they were exposed, there was a strong chance of dying at the hands of the predator or at least getting harmed.

[Maretta M.]

Two characteristics present in the Mudskipper video are Growth and Development and Adaptation. These characteristics are seen in the physical appearance of the Mudskipper. Firstly, the Mudskipper has legs and a long body that allow it to move through the thick mud. This adaptation allowed the fish to leave the water and enjoy the rich feeding ground that the mud has to offer. Further, the development of this body type allows the fish to jump high into the air and attract a mate. A second adaptation that allows the fish to survive is the position of its mouth. The Mudskipper’s mouth is at the bottom of its face, perfect for picking up food as it moves through the mud. Another example of growth and development is the Mudskipper’s ability to breathe on land. Outside research showed that the Mudskipper breathes through its skin, allowing it to survive outside the water. Life on land is further supported by the development of larger gill chambers. These larger gill chambers hold a large air bubble, which also helps to allow the fish to live on land. (http://www.wetwebmedia.com/ca/volume_7/volume_7_1/mudskippers.html)
I can hypothesize that this pocket of air would help the Mudskipper to live even while buried under the mud. In the beginning of the video, the fish emerged from beneath the mud. While I do not know how deep the fish was buried, it is likely that there was less air reaching the Mudskipper beneath the mud. The stored air pocket would allow the fish to survive even in these conditions.
I came to these conclusions, because the adaptations and growth and development discussed above allow the Mudskipper to survive and supports the growth of future generations of Mudskippers. Without these characteristics the Mudskippers would be unable to survive on land, and thereby unable to eat the food that the mud provides.

Two characteristics present in the squirrel video are Interactions and Detection and Response to a Stimulus. Both the baby squirrel and the big squirrel interact with each other, the people, and the inanimate objects such as the wall and the bags that the students put down. The two squirrels interact when the big squirrel tries to teach the little squirrel how to get over the wall. Both squirrels interact with the wall. The bigger squirrel can easily jump over the wall; however the little squirrel has difficulty. He tries several times to jump, managing only to crash into the wall and fall back to the street. The people and the squirrel interact when the students put down the backpack and later the brown bags. Though the squirrel initially runs away, he always returns. When he does, he then interacts with the bags. He finds a way to use the bags as a ramp to climb over the wall. In the end, the baby squirrel’s interactions with the environment allow him to accomplish his task, climbing over the wall.
The second characteristic is Detection and Response to a Stimulus. In this video the stimulus was the introduction of the backpacks and the bags. This change triggered a response in the squirrel—to use the bags as a ramp. To the students, using the backpacks as a ramp was a logical and simple action. To the squirrel, it was more difficult. This is seen in how the squirrel responds to the stimuli. The first time the squirrel saw the bag he was unsure of what to do. When the second set of bags were put down, it took far less time for the squirrel to figure out how to use the bags to get over the wall. These responses reflect the squirrel’s increased ability to react to the stimuli. The first time using the bags as a ramp was a new concept. The second time the similar stimulus was introduced, the squirrel responded more quickly and effectively.
It can be concluded that these are characteristics of life because they allowed the squirrel to move about his environment, accomplish tasks, and gain new knowledge about interacting with the environment. The abilities to interact with its environment and respond to stimuli are important for the squirrel’s survival. No, getting over the wall was not a matter of life or death, but there will be other times in the squirrel’s life were interactions with both other animals and its environment will be far more important. These early interactions and responses to outside stimuli allow the squirrel to gain experiences and knowledge for future survival.