EVOLUTION vs. METAMORPHOSIS

As I have been reading your posts from the Home Learning assignment where you had to identify and relate one of the 8 characteristics of life to the tadpole, I have noticed that metamorphosis and evolution have sometimes been mismatched in the way they have been discussed in the posts. I have prepared a short explanation that I hope will shed insight into the similarities and differences between these two terms.

If you chose either metamorphosis or evolution in your Home Learning assignment, I would like you, at some point - does not have to be today (and it does not have to be during class) - to read my explaniation. If you would like to leave a comment for me after reading, I added 10 writing prompts at the end. This is not a required assignment. If you do not read, you will not fail because I am not grading the comments for this post like I do the others. Even if you start reading and don't make it all the way through, drop me a comment as to how effect you think clarification like this is. To restate: how valuable is it to you, in your opinion, if I clarify concepts that I did not clearly present in class verbally, to be able to read an explanation in this blog format. I welcome your input. Thanks!


Here goes....

evolution and metamorphosis are two seemingly closely related terms. in fact, they at first may appear to be synonyms defining the same concept. i am going to try to explain to you their difference. please tell me what you understand the next time you log on and read this. the concept that many of you described in your posts as "evolution" is actually called metamorphosis.

METAMORPHOSIS
metamorphosis refers to the growth and changes that take place during the life time of an organism. in the case of the frog, a frog starts out as an egg, then grows out of the egg and when it can freely swim in the water we call it a tadpole. it has a tail and can swim around. eventually, it will change more, eating a lot and getting bigger, then growing feet. later in it's life it will be able to both walk around on the land and swim in the water. all these changes of growth are called metamorphosis.

EVOLUTION
Evolution is the name that scientists have given to the idea that over 1000's of years a particular species might change as a group. evolution is generally not noticeable in one organism during its own lifetime. let me attempt to use a frog to explain. let's say that there is a population of frogs living in a marshy area, like the mangroves or the everglades. these frogs like to live in the water and the tall grass. they eat the flies and mosquitoes that live in that area. let's imagine that there are no tall trees in this area. can you see a picture of this? let's say the year is 2007, September to be exact.

Now, let's imagine that we return to this same spot about 2000 years later, and it's the year 4012. we are still able to find these same frogs living in the marshy areas. but the place looks a little different. there are not as many mangroves as before. in one area the mangrove trees have been taken over by tall, tall, tall trees. it looks like a tropical forest. the mangroves are on the edges of the forest. inside the forest, we don't see any of the frogs living. we only see them in the marsh, where there is water.

Then, at night, we camp out in the forest and we hear lots of frog noises but we can't see any of them on the forest floor. where is the noise coming from? YUP!! look up! if you can believe it, there are lots of TREE FROGS happily chirping high, high up in the top canopy of the leafs of the trees. so, we get some climbing ropes and climb the trees to get a look. we are astonished to see that the frogs look almost identical to the frogs that live in the marsh!!! But, one thing is drastically different. The tree frogs have a different type of webbed feet. Their feet make it so they can easily climb and move around within the tree canopy.

We decide to take a few tree frogs and do an experiment with them. We take them down to the marsh to see if they can swim. In fact, they can! But not very well. Nothing like the champion frog swimmers that live in the marsh. We then take some of the marsh frogs, climb back up the tree, and see how good they are at hopping on tree limbs 200 feet above the ground. They are pretty clumsy. A few even hop off the limb and fall.... down... down.... and luckily get caught in the safety net we set up just in case they did fall off. Their expert webbed swimming feet make hopping on high branches a difficult feat.

So, now we come to the question: How did these tree frogs get here? Where did they come from? When did they come? Why are they different from the marsh dwelling frogs ONLY in the appearance and function of their feet?

What scientists have come up with to explain possible answers to this questions is called EVOLUTION.

Evolution is defined as the gradual change in a species over time. It is not the change in a single individual over time. This would be called metamorphosis.

In this hypothetical situation of tree frogs and marsh frogs - which I am hypothetically suggesting - we would want to look at all the frog fossils between the years 2007 and 4012. We would look and see if there was any gradual change in the bone structure of the feet that suggests that their were genetic (DNA) mutations that caused the feet to change over time, or rather, adapt to the environment.

What scientists would want to study is if the tree frogs were at one point the same marsh frogs. By 4012, they have clearly evolved into two separate species. They are not suited to live in each other's habitats.

TO SUMMARIZE:

This gradual change in species over a LONG period of time (1000's, thousands, of years) is called EVOLUTION.

The changes that happen in the life cycle of a particular individual (between conception and death) is called METAMORPHOSIS.


Student:
Please post some feedback (optional). In the name field, write your student ID and the Period of Bio, so I can easily identify you.

For example: In the Identity field-

NAME: 1234567 Period 3

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NAME: 0987654 Period 8

Thanks. This is an optional post. There is no extra credit that you will receive. You are not required to read or comment on this particular post.

If you do: I would like to hear one or more of the following of your opinions.

1) In your own words, how would you explain Metamorphosis?

2) In your own words, how would you describe Evolution?

3) In your opinion, what do metamorphosis and evolution have in common with each other?

4) In your opinion, in what ways do metamorphosis and evolution differ?

5) If a classmate asks you to explain both evolution and metamorphosis, how would you explain it?

6) How clear did I (Ms. P) explain the concept of evolution and metamorphosis?

7) How has your knowledge of these two characteristics of life changed after reading this post?

8) In your opinion, do you prefer to learn about something online, like this - or do you prefer to listen to a teacher talk in a classroom and teach a concept? Explain your preference.

9) What other concepts do you go to the internet to learn about? Would you say these concepts are related to your social teenager life or they are academically related to schoolwork.

10) Any other comments that are in your head, being relevant and appropriate, feel free to add.

DON'T FORGET TO TELL ME THE PERIOD YOU ATTEND BIOLOGY!!!!!!!!!!