Bio 103 Week 4: Time, Diversity, and Evolution

Paul Grobstein's picture

Glad you're here, to share explorations of life. If you're registered in Biology 103, remember to log in before posting here. Others are welcome to contribute without logging in. Such comments though will be checked to avoid spam postings and so be delayed in appearing.

In any case, remember that this isn't a place for polished writing or final words. Its a place for thoughts in progress: questions, ideas you had in class (or afterwords), things you've heard or read or seen that you think others might find interesting. Think of it as a public conversation, a place to put things from your own mind that others might find useful and to find things from others (in our class and elsewhere) that you might find useful. And a place we can always go back to to see what we were thinking before and how our conversations have affected that. Looking forward to seeing where we go, and hoping you are too.

You're free to write about anything that came into your mind this week. But if you need something to get you started, what did you think of our survey of scales of time relevant to living things? Of of the diversity of living things?  How does all this relate to thinking about evolution?

LaKesha's picture


I thought that the lab from this week was amazing. I am a hands-on person so when we got to prepare our own slides and analyze them, it was so much fun. I really enjoyed watching the cells through the microscope and seeing what happened and performing different trials. I didnt expect to see so much especially when we looked at the onion peel. The detail was incredible and watching what happened when we added substances was very cool. I really felt like I learned a lot in the lab.
r.mabe's picture

language of description

While I was researching for my web paper I had a tough time choosing a topic. I realized that many of the topics I was interested in were very abstract, philosophical, or foreign and as a result difficult to talk about in concrete terms. That is partially why I like this class/Professor Grobstein's approach to science. He presents us with concepts that are hard to grasp and make us feel uncomfortable. But the idea of organizing a paper on an abstract idea was unmanageable. For example last week we were talking about the size, rate of expansion, and limit of the universe. This greatly interested me and seemed like a good topic for my web paper. Yet, the more I tried to think and talk about it the messier it got in my head. Discussing outer space in a logical fashion is onerous because it's outside our realm of understanding. The idea that space is continuously expanding is intangible; what is outside of space? What is it expanding into? Nothing? It seems to me that it is difficult for us to grasp not only because the universe functions on different spacial and temporal scales than we are used to thinking about, but also because the language we have is inadequate. We normally use the word "space" to talk about an area that is habitable, a particular place, of definable size. Even when we say that there is an empty space, it is not actually empty, there are trees, grass, a room, concrete...something. But "space," outerspace, is also the word that we use to describe the "space" outside the earth's atmosphere. And since the universe is expanding, what space is it expanding into? How can we even begin to talk about something that is so hard to grasp? If the answer, or one of the possible answers, is nothing how can we even begin to fathom that? How can there possibly be nothing if space, outerspace, is expanding into it? Perhaps the word "space" isn't even the right kind of word to apply to what is at the edge, if it has one, of the universe.
PS2007's picture

I agree with many people

I agree with many people who have already posted in saying that I really enjoyed the lab on Wednesday. I always dreaded labs in high school because it seemed like we were all supposed to look for one right answer, and if we didn't get it right we would get a bad grade or not be able to complete the lab report. I think my high school experiences with science made me think that I hated science, when in fact I just hated the way it was being taught. I'm really enjoying looking at science in a different way, and not being afraid to make mistakes.

It was also really interesting to look at cells under the microscope. It's crazy to think that we are all made up of cells, and now when I look at a plant or animal I wonder how it's cells look. I hope that we get to spend more time using the microscope.

Ruth Goodlaxson's picture

I thought lab this week was

I thought lab this week was definitely interesting. The microscopes were a little frustrating to work with sometimes, but I thought it was cool to be getting so hands-on with something I don't actually know very much about. Yeah, I have some vague memories of cell structure from 9th grade bio, but not a whole lot. I think that made the discussion and reports to the class a little more genuine. We know and can recognize the difference between trees and grass, so the past two labs it was hard to "attack" people and come up with arguable ideas. But because we were actually trying to create knowledge for ourselves, I think the process of presenting and attacking was actually pretty genuine and helpful.
LaKesha's picture

Overlapping Species

Class was very interesting on Wednesday! It was similar to our trips in lab to the other worlds. It was interesting to see how everyone placed the cards you gave us differently. We all had similar piles in terms of what we put together but where we put them was different. Some grouped mammals, some did seaplants and animals that live in the water together, etc. I feel that becuase everyone comes from different places and learned science very differently, that we all have our own ideas about how we classify species. I also feel that we can't disagree with what someone else says because their opinions aren't wrong, just different than the other persons.
Rachel Tashjian's picture


I was a little bit nervous when I came into lab on Thursday. Just looking at the microscopes brought back all these tedious memories of grid paper and tables and putting things into arbitrary categories (kind of like the movie "Office Space"). But first of all, looking at the cells was really interesting. Admittedly, a few looked just as I would have expected, but some, I put under the microscope and it was a bit like watching an iPod commercial, or that sensory-overload "Sgt. Pepper's Lonely Hearts Club Band" movie from the 70s. I felt a little like Sal Paradise in On the Road: "And the word was: Wow!"

But what was even more interesting to me was what happened during our oral presentations. We were just kind of discussing things, asking and answering questions, and my lab partner almost offhandedly said, "Maybe cell size is in relation to their stages of development." Then each group seemed to come up with more great ideas as to what cell size could correlate with. I just thought it was so cool that the most interesting observations we made seemed to be stumbled on accidentally. 

Catrina Mueller's picture

The lab this week really

The lab this week really got me thinking about how we can view the world differently with the use of technology such as a microscope. Things look completely different when viewed in different manners. It is very important that we take all view of things and observe them so that we can have a more "correct story" off of which to base things.

It got me thinking a bit about how humanity's views changed over the ages due to improving technolgy. Everything can be revolutionized due to one tiny observation or the invention of a new technolgy that provides a new scope to things. It's funny how quickly things so set in stone can be changed.

MarieSager's picture

ok that last line reads

ok that last line reads wrong- i meant to say that it doesn't seem to follow that being small means functioning less well or being able to do less.
MarieSager's picture

Looking at how diversity is

Looking at how diversity is organized, it seems like such a daunting task. It also, in some ways, seems like an arbitrary task. I mean, the way we look at science, new observations can always be found. And if new observations can be found, then isn't it possible that plants/animals/everything can be classified in new ways based on those findings?

Im also really broadly thinking about function. One of the questions brought up in lab was "does size relate to function?" I don't really know the answer to that. Small cells that make up life can do so much and are so essential- so it doesn't seem to follow that does smaller mean you can function less well or that you can do less? I think it is something interesting to consider. 

LuisanaT's picture

And I thought we were going to revisit planet farther again

I was happy to see that this week's lab posed a question that did not have a set answer to it. We, as scientists had the freedom to choose how to approach and test the prompt. We also had the liberty to make up stories for all of the observations made that day. This kind of thing not only leaves us with questions unanswered but with more questions to think about which I feel like is the most crucial difference between all labs I have ever done before entering college. The fact tthat here is an inifite number of possible "wrong" hypotheses and only one "right" one to answer life questions opens up doors to an infinite number of more hypotheses to question life.

Jen's picture

I really enjoyed our lab

I really enjoyed our lab this week. To be honest, I wasn't really sure whether cell size was dependent on organism size. It was interesting to see how different plants looked similar under the microscope at a smaller scale, thus enabling me to directly experience what we were discussing in class; that there is less diversity at smaller scales. 
Kee Hyun Kim's picture

clear distinctions?

 Like what others said, in the beginning of this week, it looked as if we were going to have some clear distinctions for once. The classification between autotrophs and heterotrophs seemed pretty clear and after all the confusions we went through; i was releived to see some clear distinctions and boundaries. However, with the example of fungi’s, again there proved to be exceptions to this way of grouping... 

Although, we are yet to find any clear cut definition for anything, i have learned a lot from this week. (especially from our lab Thursday). Posed with the question of does cell size have effect with the size of the organism, i thought there could be no possible connection between the two since organisms vary so greatly in size while cells are relativiely similar in their size. However, there seems to be somewhat of a connection between them since larger organisms tend to have more complicated cells and complicated cells tend to be larger in size than simpler ones.   

This story was strengthened by our lecture (?) on the prokaryotes and eukaryotes. Only single cell organisms (which are therefore much simpler and smaller) had prokaryote cells ( which do not have walls and are smaller)


Although there havent been any clear boundaries or distinctions about living organisms, I think I have learned a great deal about life and what composes them.




andrelle's picture

I like the lab on wednesday

I like the lab on wednesday because i felt like we actually got somewhere in trying to figure out how we are different even though we are all made up of cells.  Before, even though i left with questions, sometimes i felt as if we were never going to get anywhere.  I guess I am just someone who likes to have definitive answers sometimes.

In lab, we decided that the difference in cells has to do with a number of different reasons.  Some of those reasons have to do with the environment of the cell, the stage that the cell is in, or even where the cell is located in the organism.  I think that things in general has several reasons why they are the way they are, and that it's never one clear cut reason.  That's why its hard to group things in definitive categories, there are always going to be overlapping.

kcough's picture

cells, colors, sizes, etc.

I agree with Sharhea, I thought this week's lab was a lot of fun. I was surprised by the fact that the size of the cell has no bearing on the size of the organism-I thought it would make at least a little bit of difference. I also found it interesting that within an organism cells not only varied in size but also in color. Biology is fascinating. Living organisms are so phenomenally complex-cells, as we discovered, vary not just because of one factor but because of many-complexity, development, function of the cell, age and history, environment, genetics...the fact that there are no rings on the trees (because cells stop growing in the winter, which makes the rings, and if there is no winter...) I thought was really interesting.
The more we study this, and the more I research my web paper, the more I understand how complex science is. There are no real right answers. Everything is interdependent, including all the information. I'm becoming more comfortable with the idea, though it was nice to have something that I could think of as definitive, but I guess I'll just have to let that go....

Sharhea's picture

Thinking about evolution

I really enjoyed this week's lab. I have never really had the privilege of working with a microscope. We discussed what makes the cells vary after all the groups presented their findings. We really got into the topic of how cells may vary for many different reasons including climate/weather, or simply over time changes as their surroundings change. Evolution is all about organisms developing over time, changing as their environment, etc develop. The cells that we looked at in class differentiated in organisms' size e.g small flower like the buttercups vs huge tree like the pine. The pine tree changes over time or in different climates, but the amount and/or size of their cells would always have some set range because of the simple fact that it is a pine tree.  
eharnett's picture


I thought it was intersting that, after our discussion on Friday, we "determined" that there is not random variation but rather nested clumps of diversity. Because there are so many similarities between organisms at different levels and scales, it seems like this would make sense. However, according to Darwins Theory of "survival of the fittest", shouldn't part of evolution be random variation? Along the way there must have been some sort of variation that allowed for certain organisms to be "fitter" and reproduce more successfully than others and therefore allow for their genes to be passed on. Maybe I am thinking about this the wrong way, but that was what puzzled me after class-there must of been some type of random variation.
ekim's picture

on categorizing & diversity.

the last few classes when we discussed life and spatial scales, it always seemed to have some unexpected twist by the end of the lessons: maybe there are no sharp boundaries between living and non-living things, maybe there IS a limit to spatial scales (& therefore, the universe).

but today in class, we actually categorized living things into autotrophs and heterotrophs. we made sharp boundaries.

but thanks to fungi, we're back where we started: there are no sharp boundaries because fungi took its place in between the autotrophs & heterotrophs.

& i actually like it without sharp boundaries because not everything's black and white...there's always a gray area.

Paul Grobstein's picture

grey areas

Yep, lots of grey areas in life. But careful ... fungi are plant like in some senses but are clearly heterotrophs (animal like) in one. They depend for their energy on other living organisms rather than being able to get it from non-living things.
Samar Aryani's picture

I liked the discussion in

I liked the discussion in class on Wednesday about the differences between plants and animals. It was concluded that plants and animals are in two different groups (aka 'clumps'). We elaborated on the differences by categorizing them. First, as stated before, plants are autotrophs and animals are heterotrophs. The second distinction is that plant cells have walls and animals do not. The third is that animal cells move a great deal in their development, whereas, plants do not move their cells around. The last differentiation being that plants themselves do not move around. This seemed very logical but what struck me was the idea that there are no living organisms that connect the gap between the two groups. I never thought of it in that manner and after thinking it over, I could not think of any group that would fill that gap. The great thing about science is that there are always new discoveries, maybe one day that gap will be filled. Hopefully this discovery will happen because as said in class, classifications will change when new observations are made.