conclusion
evolution from phylum porifera to phylum chordata
1. Lower Invertes
|
2. Higher Invertes
|
3. Chordata
|
The best adapted organism to life on earth
Sponges are the most adapted organism to life on Earth. Sponges are incredibly simple organisms, but that is what allows them to survive and thrive. Their simplicity frees them from having to eat a lot while allowing them to survive through harsh environments and environmental changes.
In the beginning when the Earth was first forming, sponges were the first animals to evolve. As such, they do not display some of the more “advanced” characteristics that other animals display. They do not display true tissues, symmetry, segmentation, cephalization, a coelom, or even germ layers. Sponges are simply made up of some very cooperative cells. The cells work together to ensure that each cell is nourished and functioning properly. For example, a sponge feeds by filtering the water in it. They have flagellated choanocytes (also called collar cells) that line the inside of the sponge’s cavity (called the spongocoel). The flagella of the collar cells create a wave that causes a current of water to flow through the sponge. While creating this current, the cells also capture food particles from the water. The food particles travel through the choanocytes and into the amoebocytes which digest them. Amoebocytes then carry the nutrients to the other cells in the sponge. This system works quite well for the sponge. It gets nutrients to all of its cells while not costing the expending much energy. Sponges do not eat much, nor do they need to hunt for their food which allows them to focus on living.
Furthermore, they do not need to expend any of their energy on finding mates. Sponges can reproduce asexually and sexually. This gives sponges great versatility in reproduction. They create gemmules if they sense a massive change in their environment to ensure species survival, and their sperm and eggs double as choanocytes and amoebocytes respectively. Despite being so simple, they do not have any unnecessary parts or systems. With having such a simple make-up, they reduce the risk of malfunctioning parts or organs which reduces the risk of premature death. Reproducing sexually is quite easy for a sponge as they just wait for some sperm to come along to fertilize their eggs. It is much like how they eat: they do not need to go out in search of sperm, they merely need to wait and it shall come.
The theory goes that at the time when the Earth was being formed, it was a very extreme place to live. When sponges first came into being, the Earth was not very hospitable to or accommodating of the various forms of life we see today. Sponges (and perhaps other simple organisms) would be an exception. We as humans need to maintain a constant body temperature and pressure or we will die. It would be impossible for us to live in extremely cold regions without the technologies that we have developed (such as clothing). Sponges, however, are able to adapt to and live through those harsh environments. Not only are they able to survive through extreme temperatures (so long as the water they are in does not freeze completely), they are also able to survive through incredible pressure changes. If pushed through a sieve, a sponge will regenerate within three weeks. A sponge is basically a gathering of cells that cooperate with each other in order to survive. Because of their lack of true tissues, their cells can easily reform into a new sponge when broken apart.
One might think that living on land is superior to living in water, but this may not be entirely true. Sponges must be surrounded by water to survive. That might sound very limiting, but remember: we, as humans, are trapped on land. Water is more plentiful on our wonderful blue planet, making up around 75% of the globe. Therefore, being able to live in water is far better in terms of survival than being able to live on land.
So why are sponges the organisms that are best adapted to life here on Earth? Well, sponges are able to spread out all through the ocean, surviving way deep down where we cannot reach without the aid of advanced technology. They are able to survive in more areas than any organism on land can. Sponges do not have to waste their precious time and energy with hunting for food. They merely stay attached to one surface their entire lives and pick out the pieces of food that flow by them. They have great versatility in reproduction because they can reproduce asexually or sexually and neither cost the sponge much energy. And lastly, living in water is far superior to living on land because there is more of it. All these are reasons why the sponge is the organism that is best adapted to life on Earth.
In the beginning when the Earth was first forming, sponges were the first animals to evolve. As such, they do not display some of the more “advanced” characteristics that other animals display. They do not display true tissues, symmetry, segmentation, cephalization, a coelom, or even germ layers. Sponges are simply made up of some very cooperative cells. The cells work together to ensure that each cell is nourished and functioning properly. For example, a sponge feeds by filtering the water in it. They have flagellated choanocytes (also called collar cells) that line the inside of the sponge’s cavity (called the spongocoel). The flagella of the collar cells create a wave that causes a current of water to flow through the sponge. While creating this current, the cells also capture food particles from the water. The food particles travel through the choanocytes and into the amoebocytes which digest them. Amoebocytes then carry the nutrients to the other cells in the sponge. This system works quite well for the sponge. It gets nutrients to all of its cells while not costing the expending much energy. Sponges do not eat much, nor do they need to hunt for their food which allows them to focus on living.
Furthermore, they do not need to expend any of their energy on finding mates. Sponges can reproduce asexually and sexually. This gives sponges great versatility in reproduction. They create gemmules if they sense a massive change in their environment to ensure species survival, and their sperm and eggs double as choanocytes and amoebocytes respectively. Despite being so simple, they do not have any unnecessary parts or systems. With having such a simple make-up, they reduce the risk of malfunctioning parts or organs which reduces the risk of premature death. Reproducing sexually is quite easy for a sponge as they just wait for some sperm to come along to fertilize their eggs. It is much like how they eat: they do not need to go out in search of sperm, they merely need to wait and it shall come.
The theory goes that at the time when the Earth was being formed, it was a very extreme place to live. When sponges first came into being, the Earth was not very hospitable to or accommodating of the various forms of life we see today. Sponges (and perhaps other simple organisms) would be an exception. We as humans need to maintain a constant body temperature and pressure or we will die. It would be impossible for us to live in extremely cold regions without the technologies that we have developed (such as clothing). Sponges, however, are able to adapt to and live through those harsh environments. Not only are they able to survive through extreme temperatures (so long as the water they are in does not freeze completely), they are also able to survive through incredible pressure changes. If pushed through a sieve, a sponge will regenerate within three weeks. A sponge is basically a gathering of cells that cooperate with each other in order to survive. Because of their lack of true tissues, their cells can easily reform into a new sponge when broken apart.
One might think that living on land is superior to living in water, but this may not be entirely true. Sponges must be surrounded by water to survive. That might sound very limiting, but remember: we, as humans, are trapped on land. Water is more plentiful on our wonderful blue planet, making up around 75% of the globe. Therefore, being able to live in water is far better in terms of survival than being able to live on land.
So why are sponges the organisms that are best adapted to life here on Earth? Well, sponges are able to spread out all through the ocean, surviving way deep down where we cannot reach without the aid of advanced technology. They are able to survive in more areas than any organism on land can. Sponges do not have to waste their precious time and energy with hunting for food. They merely stay attached to one surface their entire lives and pick out the pieces of food that flow by them. They have great versatility in reproduction because they can reproduce asexually or sexually and neither cost the sponge much energy. And lastly, living in water is far superior to living on land because there is more of it. All these are reasons why the sponge is the organism that is best adapted to life on Earth.
is my portfolio a sound piece of evidence for evolution?
I would have to say no. Firstly, I haven’t bothered to hide the fact that I don’t believe in macro-evolution thus far. In fact, I have offered my skepticism for scrutiny in a lovely multi-paragraph write-up on the evolution and taxonomy page. I find evolution and it’s connection to the living world endlessly fascinating and I certainly hope to continue to study it, but I do not believe it. I feel that my stating my disbelief of evolution detracts from this portfolio as being a solid piece of evidence. Furthermore, as a student, I have had the generally accepted theories, however unproved they are, handed to me as fact. As such, I have had a lot of exposure to the theory of evolution and how it ties into biology and have merely rewritten what I had learned in class on this website. These ideas and “findings” were predetermined learning outcomes and previously tested experiments for me to “discover”. Everything I have shared on this website comes from another source. That source (the school system) has deemed it appropriate that I should learn about evolution, so here we are. I have certainly shown the increasing complexity of organisms from Porifera to Chordata, but I have not provided how that would have happened. This information being omitted also detracts from this portfolio as being a solid piece of evidence. Thus, I would have to say that my portfolio is not a very good piece of evidence of evolution.