BIOLOGY 103
FALL, 2000
FORUM, WEEK 3


Name: Paul Grobstein
Username: pgrobste@brynmawr.edu
Subject: week 3
Date: Mon Sep 18 11:02:09 EDT 2000
Comments:
So .... we're running a little behind the announced schedule but ... talking about a variety of interesting/worthwhile issues. Last week's thoughts have been moved to their own file. Which isn't necessarily to say that we need to start fresh this week. There was an interesting conversation last week about whether or not there was a "first organism" which we might want to continue, in and of itself as well as because we'll find that similar issues arise in a number of other contexts. There is also the question of whether "change" is a fundamental part of life, and my more general assertion that there's a great similarity there, that both science and life are continuing processes of exploring what is and can be, with a characteristic alternation between periods of trying out new things and periods of testing what has been found. Look back, and see if there are issues from last week you want to continue thinking about/working on ... or talk about what this week (space, time, diversity, evolution) makes you think?
Name: Rachel Hochberg
Username: Garg0yle99@hotmail.com
Subject: life bigger than 10^10?
Date: Mon Sep 18 12:31:56 EDT 2000
Comments:
When I first considered the question of whether or not there was life larger than 10^10, my immediate reaction was "no." After all, there aren't any animals that size anymore, and I don't think any of the dinosaurs were that huge, either. Then I reconsidered; maybe there is a living organism that's just so large that it is usually overlooked. I went back to the criteria we decided upon in class, and soon came to the conclusion that, technically, the entire galaxy is one living organism. It's definitely an improbable assembly. It is also dependent on energy--all of the stars that make up the galaxy are, in essence, energy themselves. The Milky Way also "reproduces" with variety--other stars that are made up of the same atoms form other galaxies, similar but never exactly the same. The galaxy can change due to outside stimuli, such as black holes changing the orbits of masses within the galaxy, and the galaxy is also autonomous in that it often changes for internal reasons, such as supernovas. Although a collection of stars and planets may not seem like a living organism, by our class' criteria it just may well be.
Name: Katie Kennedy
Username: kkennedy@brynmawr.edu
Subject: Our Connection to the Universe
Date: Mon Sep 18 15:08:09 EDT 2000
Comments:
I thought Prof. Grobstein's final comment today (monday) was especailly interesting, that is, as he pointed out, how biologically we are connected to the rest of the universe. I have always thought of the universe as this great, all encompassing, intangible. However, the more I think about it the more I realize that this is such a "human" way to look at things. Is it just because we do not yet have the technology to completely explore the universe or land on planets in far off galaxies that many of us cannot even conceive of the massive size of the universe or an organism that is larger than 10^10 in size? How narrow minded we are! I find it incredibly interesting as well that here we are made up of atoms that come from such distant places- that these tiny little atoms made the journey to earth- and yet we, with all of our knowledge, may never be able to visit the origins of our components.
Name: jeanne
Username: jbraha7563@aol.com
Subject: criteria for life
Date: Mon Sep 18 18:14:57 EDT 2000
Comments:
a quick thought about the universe as an organism: one of our criteria for living organisms was that they be bounded. my very basic knowledge of astrophysics tells me that the universe is constantly expanding. if so, is it bounded and the boundary keeps getting bigger? i'm inclined, for no great reason other than a hunch, to say that the universe is not bounded.
Name: Gloria Ramon & Joan Steiner
Username:
Subject: Bio Lab #2
Date: Tue Sep 19 15:27:20 EDT 2000
Comments:
Does the size of the organizm depend on the size of the cell? Someone thought so, albeit I am questioning what they were thinking, yet out of respect for my collegues I generally accepted it until I went out with my partner to prove otherwise.

We collected four different plant organisms, ranging in size from 35'+ to 3" tall. The samples consisted of a leaf from a maple tree, a leaf from a 6' tall bush, a blade of grass measuring 5", and a little three leaf clover measuring in at 3".

After converting our samples into slides where we could observe the size and structure of the cell, we collected the following data: Tree cells averaged in size 41.6 micrometers; Bush cells 23.4 micrometers; Grass cells 55.9 mircrometers; Clover cells 26.87 micrometers.

Due to the variety of sizes ranging, there is no solid evidence present to proove that cell size determines organizm size. First off, the largest organism obviously did not display the largest cell size, the organism which did so measured only 5", the second smallest organism in the sample series. The Bush and Clover, two organisms varying greatly in size did not do so with their cell size, since at average measurements of 23.4 and 26.87, the sizes were relatively close.

From our general observations, we noted that the structure and shape of the cell was relatively similar to the overall structure of the organism or the large sample we collected. The cells which came from leaves which were jagged and pointy around the edges had cells with ridged and pointy edges; the grass had long, retangular shaped cells and the clover had small, round cells.

Even though our evidence somewhat disproves that cell size is not relative to organism size, we cannot make a general conclusion that it definitely does not determine size, since we feel that for the larger organisms our samples were not fully adequate. It is possible that the cell structure in the bark, branches, trunks, roots, etc. differ. So it seems this experiment of ours has left us hanging at a cross road.


Name: sonam tamang and aashna hossain
Username:
Subject: bio lab #2
Date: Tue Sep 19 17:58:30 EDT 2000
Comments:
Question: Does the size of a cell determine on the size of the organism?

Jeff's hypothesis: the larger the organism, the larger the cell's size would be. Basically, it consisted of the concept that an organism's size is directly related to its cell size. We found this hypothesis to be wrong: we picked three different plants that grew on the ground as samples to be used in observation in trying to prove the hypothesis wrong.

We went to the courtyard and gathered three sample plants. All three plants that we collected were from the ground. The largest leaf that we collected measured 7cm x 4 cm, the second largest leaf measured 4.5 com x 5.0 cm and the third leaf, the smallest one, measured 2.5cm x 2.2 cm.

We scraped off cell-layer samples off the surface of the leaves onto the slides. For each leaf, we took three samples as we thought getting the average sizes would be more accurate.

The largest plant's cells averaged 39 micrometers; The second plant's cells averaged 19 micrometers and the smallest plant's cells averaged 32 x 83.2 micrometers (it was rectangular in shape unlike the other two which were circular-shaped cells).

We observed the cells to be similar in shape although the third plant's cells were slightly more rectangular. Also, we noted that the sizes of the plants themselves measure as a ratio of 2:1, as in the largest plant was almost double in length to the second plant's size while the second plant's length was double that of the smallest plant.

Results: The first two plants did provide evidence that plant size determined the cell sizes. But the third and smallest plant's result went against the hypothesis since its' cell size averaged to be greater than those of the largest plant's cells.

Problems:

· Are three samples enough to determine the size or average size of the plant's cells?

· We only observed tiny parts of a huge organism. It might not have been enough just to pick up one or two leaves and then scrape samples off of the surfaces. Maybe further sampling would be more accurate.

Overall Conclusions:

Although our evidence seems to challenge the hypothesis, the problems mentioned above could be a factor toward invalidating the observations we have made.


Name: Leila Ghaznavi
Username: lghaznav@brynmawr.edu
Subject: D'oh!
Date: Wed Sep 20 12:31:42 EDT 2000
Comments:

Just to toss in my skeptical view point of the day (it's starting to become a trend for me):

In class we talked about diversity falling into "natural" divisions, clusters. And though I'll agree that it seems that the vast majority of creatures do follow this structure there are always exceptions, admittedly few and far between, but they drill holes in our clusters. We said plants don't move, that isn't necessarily true. There are documented cases in the rainforests of entire groves of trees that move through out the forest in search of nutrients. They do not move quick enough for the human eye to notice at a glance but they ARE moving at a rate that can be observed over the span of a day or two. The reason I brought up the duckbill platuspus however you spell it in class is because it is an example of another creature which crosses boundaries, a mammal that lays eggs. Our text book talked about the arguments people have about classifcations of bacteria and single cell organisms. So what I would say overall I guess is that life may cluster, but it doesn't cluster neatly. There are always exceptions to the rule.


Name: allison h-c
Username: ahayesco@brynmawr.edu
Subject: comment on life larger than 10^10
Date: Wed Sep 20 00:14:23 EDT 2000
Comments:
Jeanne brought up the problem of the universe being unbounded. The universe may very well be unbounded. however, the galaxies in it certainly are bounded. It is surprizingly easy to think of the milky way or any other galaxy as well as the earth (and perhaps other planets) as living organisms. Of course, if we say that the earth is living, we are discussing the Gaia Hypothesis. The problem with the earth being living according to our definition is that it doesn't reproduce in the way we think of reproduction.

But, in thinking of the differences between the earth and galaxies, I had an interesting idea. Rachel pointed out that galaxies can reproduce. As far as we can see, galaxies don't reproduce other galaxies. However, this must be possible, especially if we look over extremely long time periods. Then, to the extent that galaxies can reproduce, it must also be possible that they are living. Also, galaxies reproduce parts of what make up their own galaxy. Just as animals and plants can grow and make new cells for themselves, so too can galaxies.


Name: Katie Kaczmarek
Username: kkaczmar@brynmawr.edu
Subject: universe as organism
Date: Wed Sep 20 14:54:40 EDT 2000
Comments:
There has been some speculation on whether or not the universe is bounded. How can we say the universe is expanding if it doesn't have a boundary? I for one cannot imagine anything unbounded expanding; if someone else can explain such a visualization to me, I would be very interested. However, bounded or unbounded, if the universe is expanding, what is it expanding into? Perhaps our future physics majors would like to ponder that....
Name: Naomi
Username: nlim@brynmawr.edu
Subject: structure and patterns
Date: Wed Sep 20 19:15:29 EDT 2000
Comments:
It's interesting that, in class, Professor Grobstein created his diagram on organisms in a hierarchical fashion because mine was more in the form of a circle. While, "persons" was up at the top of my diagram as well, the other organisms were more scattered, while still in the pattern suggested by the class (in terms of the distance/space apart). Did anyone else construct their diagrams differently? I'm wondering whether this "down and up structuring" is more of an individual or general creation.
Name: anonymous
Username:
Subject: stuck on life
Date: Wed Sep 20 20:19:45 EDT 2000
Comments:
so i'm still thinking about this whole what is life thing. excuse my backtracking. i have been following the whole conversation around how we think that the bounds of life are between a cell and a blue whale (or a universe). we talked before about how we think of life as something similar to ourselves. i think this has always been the source of my aversion to science, or more specifically certain realms of science. i can understand the theory behind a cell being alive, and i understand the uses of studying cells, etc. i have always been very content to leave it to other people, though, because it seems so disconnected from my experience. i'm a political science major because i can relate to what i study. i guess what i wonder is what it is that makes scientists feel connected to something that seems so theoretical and distant to me. i realize that science is relevant to our lives, but so are millions of things. what makes someone feel so connected to cells, or molecules that they devote their life to studying them? i respect them for it, and at the same time don't intuitively understand it.
Name: Debbie
Username: dplotnic@brynmawr.edu
Subject: perspective
Date: Thu Sep 21 14:18:57 EDT 2000
Comments:
I’ve been thinking about the Gaia hypothesis that postulates that the Earth is a living organism. But as Professor Grobstein pointed out and Allison mentioned in her posting the hypothesis does not totally fulfill the definition of living that our class has put forth because to what we can observe the Earth does not reproduce. However, upon reflecting on the vastness of things, i.e. our class discussion of galaxies and patterns and yesterday’s lab involving cells I started thinking about why the Earth itself reproducing may or may not matter.

In the morning we looked at the vastness of the space between objects that make up solar systems and galaxies and saw no patterns in the emptiness. And then by gaining enough perspective, by allowing more units (planets, stars, clusters of stars, galaxies) into view we could see pieces, i.e. the galaxies that make up the entire universe. And as was also discussed, new galaxies do in fact form. Then in the lab we looked at cells under the microscope. Clearly, we knew, as we looked at those cells that they had been living parts of a more complex living thing (tree, bush, person, etc). And of course one of the reasons that we could not “verify” Jeff’s hypothesis was that even if there was some correlation between cell size and organism size, we needed only to remind ourselves that we were looking at only one example of a cell, among layers and types of cells that came from only one part from an organism with many parts, layers and types of cells.

Perhaps, we have trouble with the concept of the Earth as alive because we cannot understand the pattern. Even though we can see pretty far, we cannot yet see far with much clarity. We don’t know that the Earth is not an organism, a cluster of organisms, or a part in a much larger organism with vast empty spaces between its cells. The spaces between or inside of our cells do not, from our vantage point, appear to be vast. But it made me realize that scale, orders of magnitude and perspective, may be the most important concepts that science can use to become less wrong?


Name: Nimia Barrera
Username: nbarrera@brynmawr.edu
Subject: Change as a part of life
Date: Thu Sep 21 14:21:53 EDT 2000
Comments:
Change - I think - is definately a part of life. From the beginning (whenever that might have been), the earth, and everything in it, has changed. This is evident in our own lifetimes. Change is everywhere. The way we would have treated the environment ten years ago is not the same as the way we treat it today. We also have technological advances that were unheard of twenty years ago.
Name: Gloria
Username: gramon@brynmawr.edu
Subject: A bit confused
Date: Thu Sep 21 19:27:29 EDT 2000
Comments:
Wednesday in class when our disscusion on the universe was coming to a close, Prof. Grobstein stated, that the universe was formed from nothing. If I am not mistaken, "nothingness exploded". How can this be?. As we've all seen through the recent lab on cells and through our disscusions. Every living organism is dependent on each other. If this is so, how could have the first living organism been dependent on "nothing".

As human beings, we are on dependent on each other. For example, women are dependent on men to reproduce. If it be through sexual intercourse or through artificial insemination, there is a dependency on the ,male species.

Again, I question, how can something depend on nothing?


Name: Meghan McCabe
Username: mmccabe@brynmawr.edu
Subject: universe an organism?
Date: Thu Sep 21 21:08:02 EDT 2000
Comments:
To address an issue brought up in class on Wednesday, I don't think the universe can be considered an organism. Many aspects of the universe do seem to be highly improbable assemblies, but it doesn't reproduce with variation, doesn't have semi-autonomy, isn't bounded, and is not semi-homostatic (or, at least I don't think so). I don't think that just because something contains life mean that it itself is life.
Name: Jakki Rowlett
Username: jakkirowlett@hotmail.com
Subject: sumpin or nuffin?
Date: Thu Sep 21 22:06:37 EDT 2000
Comments:
I would not touch Gloria's question with a 10 ft (to the 25 magnitude) pole! Couldn't explain it even if I did fully understand it... But, it got me to thinking: the thing Prof. Grobstein calls a nothingness, I have heard called a "singularity" which is a an area of extremely high density which sucks in light and matter. It is smaller than a black whole, in fact, if I remember correctly,(someone please correct me if i am getting it wrong) Stephen Hawking claimed that they exist inside of black holes. I metion this because in light of our discussion of "firsts" I think it is a pretty ironic bit of naming.

More food for "firsts" thought: The Vendian (first) Animals section in the Eukaryotes vs Prokaryotes link in class notes...


Name: Jess
Username: jhayesco@brynmawr.edu
Subject: nothingness and existence
Date: Fri Sep 22 01:00:41 EDT 2000
Comments:
So, if the universe is 14 billion light years long, and it is expanding, what is it expanding into? What exists beyond the universe? If it is nothingness that exists beyond, how big is that nothingness? Does it have a size? Can nothingness have a size? And how can we even name it 'nothingness' if we cannot describe it nor even conceive of it? Of course, these questions are virtually impossible for us, at this time, to answer. So how can we do more than ponder or wonder over whether or not the earth is living? Even in lab we took at least five cell samples from each specimen. And earth is just one of many. How can we conclude so much based on one example? After all, we have established that we are only a very tiny, and relatively insignificant part of existence.
Name: Paul Grobstein
Username: pgrobste
Subject: being and nothingness
Date: Fri Sep 22 09:04:26 EDT 2000
Comments:
Hmmmm .... people are INTERESTED in where the universe comes from, and what might or might not be around it, huh? Good, so am I. But that IS a different course, or, to put it differently, if we spend too much time on things I've thought less about than I would like to have spent we won't spend enough time on things the course is billed as covering and that I've thought more about. So ... here's the bottom line on cosmology (for the moment). No one KNOWS where the universe came from, what is beyond it, or even whether those are meaningful questions. But there are a LOT of relevant observations, and more are being made at an ever accelerating rate. Ned Wright's Cosmology Tutorial provides a very nice summary of them, and of their implications (see his FAQ in relation to "what's around the universe?"). And it is unquestionably one of the most interesting/productive areas of science at the moment, in the sense that, if nothing else, it is clear that the observations will require changes in our intuitions at levels so deep that some existing "ultimate" questions may indeed cease to exist and be replaced by others we cannot as yet fully imagine.

In that context, I am intrigued/bemused by Gloria's question, which seems to me another version of the "was there a first living organism?" question. If our experience is always of a diverse collection of interacting things, is it possible that that is actually a fundamental starting point (both for biology and for physics/cosmology), and that our "intuitions" (themselves the product of observations) are misleading us when we believe there must have been a first organism AND a starting point, out of "nothingness", for the universe? Can we instead get ourselves to think of an always changing but also always existing interactive collection of diverse things? What would that "look" like? And what different questions would arise (what different observations would it be worth making?) if we took that starting point seriously?


Name: Jenny Wilson
Username: wilson_jl@yahoo.com
Subject: Plant vs. Animal
Date: Fri Sep 22 10:23:33 EDT 2000
Comments:
The following is a response to the question raised at the end of class on Wednesday by Professor Grobstein: Are the distinctions drawn between plant and animal life really biological in nature? I think we, as human beings, naturally assume that the characteristics that distinguish plants from animals are both distinctive and numerous. There are distinctive difference in the cell structure, reproductive methods, and overall internal make-up. And then of course there are the external differences: color, texture, scent (we should hope), and general appearance. But are these differences biological in nature. Well, seemingly so, since the process of classification requires us to consider all of the above characteristics. However there are some anomolies--for example, the Venus Fly Trap is carnivorous (or rather, omnivorous), yet clearly of the plant family. But since it is not the only plant with this quality, it falls in to a sub-class within the plant class. Basically, we can classify several living organisms as having "crossover traits". This, however, does not supercede the basic classification scheme. Therefore, I can state with certainty that I believe that the distinctions drawn between plant life and animal life are biological in nature, as they relate to a scientifically accepted process of classification. (Brief Disclaimer: that is not to say, however, that all scientifically accepted processes are necessarily worthy of acceptance by non-scientists simply because they were formulated by those with a greater knowledge of science in general).


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