Advanced Astrobiology for Teachers II

notes from our exploration of Voyages Through Time TM

ethics of a second genesis
early hominid evolution

This will tie in a bit with the life in extreme environments course I blogged in Summer 2009

week 1 discussion:
Discussion 1
Rubrics
I use rubrics in my classroom for any sort of long term project. I especially prefer to have a rubric in place when students are to present a powerpoint or poster for an activity they performed. I also use them for some lab activities. My problem with using rubrics for lab activities is that I am in the process of changing the way labs are done in my classroom. In this transition to more inquiry type labs I have had a hard time predicting what the finished product will look like. I have had luck working with a generic rubric of what is expected in student lab reports.

The rubric obviously communicates what the expectations are on a given task. There seems to be a fine line between making a project meaningful in terms of students doing some thinking for themselves, and a project being too lined out and being borderline “cookbook”. I have found that other teachers that put information out on the web help a lot. I try to share my lessons and ideas for lessons in the virtual world myself. I find this with rubrics. Sometimes a rubric that I find online can be modified a bit and used in my classroom. Those changes can be communicated to the teacher that originally shared the resource and perhaps they can use it with the changes. Collaboration is important in the classroom for students to have a more meaningful authentic learning experience, and the collaboration among teachers can make individual lessons better, and perhaps contribute to an overall improvement of American schools in the long run. Hopefully that is why we are all here.

What is Life?
Our understanding of what is and isn't alive has changed some, but the part of biology that is the most eye-opening to me is where it turns out we are finding life. In the last 30 years we have discovered life at the bottom of the ocean where pressures were thought to be uninhabitable. But life has been discovered in extreme pressures. We had thought that life would not exist where radiation levels were high, but there are organisms that have evolved ways to deal with the mutations that would make life impossible to propagate. Extreme temperatures once thought to deny life, have yielded new forms of life, and we've found bacteria in the center of a salt crystal where the extreme salinity was thought to be impossible to shelter life. Where will we find life? The answer to that question has certainly changed in the last 30 years.


Response to James

“In a general biology classroom we typically would define things as alive that exhibit all of the following criteria:
· containing one or more cells
· a tendency towards homeostasis
· obtaining and using energy from their environment
· responding to stimuli
· growing and developing
· containing genetic information
·the ability for reproduction “

I actually appreciate the list...

“other times we create our own rubrics in our professional learning communities with collaboratively with colleagues during meetings. “


Response to Theresa
“My question is though, are there really any right or wrong answers in deciding which are the true life characteristics?”

The characteristics of life seems like a great subject for flushing out student Misconceptions about what is and isn't alive. A detailed look at viruses especially can get the wheels turning about what is and isn't alive. You will find students at all levels grappling with whether or not viruses are alive. Viruses are entirely composed of a single strand of genetic information encased within a protein capsule. Is this enough to call them alive? No most say. Viruses lack most of the internal structure and machinery which characterize 'life'. So part of our answer needs of what is alive needs to address organization, and viruses do not have the biosynthetic machinery that is necessary for reproduction. In order for a virus to replicate it must infect a suitable host cell. They can't do it alone. In the end viruses do a lot that is similar to life, but they do not contain “cells”. Do viruses use energy though?

So Theresa I would argue that there aren't any right or wrong answers but many of them will uncover some misconceptions that can be addressed in a very “teachable moment”


week 2 discussion:
How do studies of DNA sequences allow us to reconstruct the evolutionary history of life?

The study of Nucleic acids has allowed us to construct the “relatedness” of organisms, and assign them to phylogeny that they belong to. Species that were once thought to be closely related to to one another have often been found to be not as related as we might have thought. The Phylogenetic trees that many scientists drew thirty years ago are now obsolete.

How far back in time do we find evidence of life on earth?
We are limited in our fossil record, in that the earth's rocks are continually scoured of evidence of life in the endless cycle of melting, deformation, and erosional forces that we call the rock cycle. But scientists have been able to study what chemicals have been present for billions of year. Some of those chemicals are signature chemicals from eukaryote metabolism that goes back as far as 2.7 billion years.

The question about guaging how easily life arose, makes my forehead wrinkle a bit. I really don't think arose easily at all. I think it took Billions of years and the perfect recipe. I know there is life all over this planet that we never expected to find, and in conditions that just don't seem to be suitable for life, but that does not mean it was easy. It was like that perfect game when everything went right, the story of this planet and it's life that is. Do I smell the “Drake Equation” somewhere in the distant or near future in this course???



So if only half of it is left, where did the other half go? I enjoyed that question from a kid in class this December. We just finished half life problems the week before Christmas break in chemistry class. I have found that giving them a table that has the number of half lives, the fraction remaining , and the decimal equivalent is very helpful. First we actually build one together then the next day I give them a very pretty printed one. On the back I also put the graph of stable nuclei so that we can discuss the ratio of protons to neutrons, and how that relates to stability.

When does the half-life start? Holy cow, that is a very good question, does the half life process start when the isotopes are formed in stars and supernovas? When these elements form out of molten lava does the half-life restart? Great now I am struggling to understand a bit...

week 3 discussion post:
Sorry I am late posting, I will be honest, I turned 33 on Thursday, and spent the last couple days in Whitefish Montana celebrating, I did not do any homework :)





I will make some replies soon on the content but my initial post will be all pedagogical discussions.



In reference to the video, which was viewed after reading of the NOS article, there have been some very interesting misconceptions that have actually been solidified by teachers in my school district. This small rural community in NW Montana is home to a questionably mortally wounded economy. Formerly the location of a large mine and at one point the largest lumber mill in the Northwest Libby made a lot of successful loggers that worked hard and made a great living. All of those economic supports are gone and the economy of this community was poor before the recent downturn of the nations economy. With all that being said one could understand that there is a large citizenry of this town that reject with fervor any environmental efforts and the science behind them. It does go as far as rejecting global warming, as we have staff that make comments in class about global warming, evolution, and other scientific theories. "Just a theory" is the big misconception that we have to work toward eliminating in our schools. The process of evaluating hypotheses is very difficult with the social influences that can be present. I know some of you have mentioned similar situations. What are some constructive, positive ways to work through these misconceptions with social roots that you have discovered?



The NOS article notes the sixth aspect of NOS is that science is socially and culturally embedded, and so is bad science. Out of the article I really found it helpful to see the restructuring of a lesson to incorporate more NOS. It was noted that carefully constructed discussion is effective for incorporation. How do you feel about your discussion skills as a classroom manager?



"Theories do not mature into laws" I would say that this is a very rampant misconception and I believe many teachers would agree that "theories mature into laws" if you took an informal poll. Someone should do that and report back on their results. We know what my hypothesis would be about this right?

After doing the origin of life timeline, one can see that the very simplest organisms existed for a very long time before the more advanced organisms began to proliferate. I find this to be captivating to think that the first organisms could have been seeded here from another planet. When we look at the ability of rotifers to survive, and the bacteria that made it to the moon and back ready to "rock and roll". I also don't have a problem beleiving that simple life forms could exist in space, when I see how they survive in the most brutal environments on this planet/

week 4 discussion:
Initial post
Analogies:

I have long used the anthropomorphism of the elements to help students understand the behavior of different elements in different groups and periods. When we talk about periodic trends I like to use the metaphoric quality of elements “acting” a certain way. There are elements such as fluorine that act as bullies, and there are the alkali metals that are wimps when it comes down to stealing or giving up their lunch money (electrons)

When I have taught evolution and natural selection, we also personify organisms at all level from single celled on up to the most complex organisms. We talk about how animals think in terms of evolutionary success, even though they are not consciously thinking about what the best behavioral choice might be in terms of evolution and survival of the fittest.


Content:
It has been nearly five years since I taught a biology course, but when looking at the phases of mitosis, I reflected a bit at how much I enjoyed having my students make detailed color drawings of all the phases. Helping students improve their technical drawing skills is as important as many other scientific skills. I viewed an EO Wilson video on youtube : lord of the ants


and it is a great example of where great drawings aid in new discoveries. As cells come together to make colonies, and then perhaps we had multicellularity, then multicelled organisms become these colonies of organisms, what then???

There was a question in our prompts for the week that asked if evolution is a necessary feature of live. In our reading it stated that prokaryotes and endosymbiosis let to the eukaryotes, which then became progressively more complex and larger. The process of evolution drove this process as new niches are showing up and disappearing as the geologic fearures of our planet were ever changing. Not just for life as we know it, but for any life to make it through even 500 million years needs evolution.




My daughter was offended by her brother on our two hour journey to Hot Springs today to soak. Her brother told her to zip her lip and made the zipper motion across his mouth and made the 'zippp' noise. She stated that she did NOT have a zipper on her mouth. She is three and still does not understand the deep meaning of the analogy. Kids we teach are at different developmental levels, but we must all know where our students are developmentally and choose appropriate analogies and metaphors.






Post 2

We stopped at McGregor lake resort today on our way to Hot Springs from Libby. This is one of the most gorgeous drives in America. The drive starts in a termperate forest, steep and dotted with many lakes ranging from small little 5 acre ponds to McGregor Lake which is over seven miles long and over 300 feet deep in parts of it. The drive is only 105 miles, but is kind of a long drive because the shortcut we take is about 25 miles of graveled mountain road that goes from tunneling through old growth until it spits us on to the south-facing bare grassy slopes on the other end of the mountain range. The views...
The McGregor lake Marina is a place that we went to have breakfast one day that we were camping with my brother, my kids favorite uncle. My son noticed that we had been here when we were camping the summer before. We went in to use the bathroom. As we went in my son said, “dad, there are no mosquitoes when there is snow on the ground” I said, “ How do you know that?” He said, “because the last time we were here we tried to eat outside and there were so many mosquitoes.“ He is five and I was impressed. He is 5 years old, where along the way is this natural inference drawing ability lost? Has the traditional education system made kids afraid to be wrong?


Post 3
Some content 'light bulbs' I would like to share

A good look at ribosomal RNA and mitochondrial DNA is a great way to help kids look at evolution, and this done while taking a look at real data. We can actually look at data, and draw some conclusions, using our inferring skills to get a better look at the process of evolution. They can better see that it is not some inexact science based on one person's opinion and faith, but a very quantified theory.

Reminder that elodea are a must have in an aquarium in a science classroom. I forgot how much fun we used to have with these giant celled aquatic plants that can be easily grown in your own classrooms.

Discussion of sponges are great way to help students understand that we do indeed have a number of organisms like sponges that show how life gets progressively more complex.

I would thank that some sort of inquiry based research project involving increasingly more complex colonial organisms would lead to students coming up with their own solid sound understandings of how multi-celled organisms might have came to be.

A moon with life?

funny:
"The hardest part will be deciding if an odd smelling atmosphere is the work of flatulent cows or volcanism."
thoughts:
Also here the comment at the bottom states "But Europa is at the bottom of a killer gravity well in the middle of a nasty radiation field, thus it truly is isolated. " I wonder, would that really stop life?
Oh and this was from either this week's stuff or the project material, not sure it is all dribbling together!





second genesis

The hardest part will be deciding if an odd smelling atmosphere is the work of flatulent cows or volcanism.

Also here the comment at the bottom states “But Europa is at the bottom of a killer gravity well in the middle of a nasty radiation field, thus it truly is isolated. “ I wonder, would that really stop life?





Barry
“May be I am missing the point but I do not understand the religious, ethical dilemmas that this research is supposedly producing.“

Obviously there are many religious folks that believe in their religious texts creation story. If science proves how indeed all life was created down to the very first chemical reaction there would be a dilemma for some. What if alien life is discovered? Perhaps humans are not the center of the universe, and the focus of all of God's creative energy? I think people might get their wires crossed up a bit and assume the aliens we discover are actually intelligent, communicative, bipeds with two eyes and a mouth and a religion of their own. We are starting to discover that is probably not going to be the case any time soon, but perhaps in the next ten years we will discover an alien life-form somewhere. It may be a place we thought we already looked or perhaps thought they could never live, and they may be in a form that we would never have imagined. But Barry, that is the problem, many religious folks are afraid of the possibilities that their faith will not hold up if they find that we are not alone and that there is indeed life on other spheres in the universe. Others feel like discovering the very beginning of life and the whole story of life's evolution would be a challenge to their faith. I personally am a committed Christian and gleefully anticipatory of the next discovery that will bring us closer to an understanding of how life began. 2-4 thousand years ago would middle Easterners have understood if God had told them the whole story of how man came to be?

Now there are some religions that believe we were seeded here by aliens, so they certainly wouldn't be so bummed if/when we discover common ancestors from somewhere else in the universe. It's all about perspective.


In reference to a second genesis:

“Thankfully, the intense blast of ultraviolet radiation from the sun would kill of any Earth hitchhiking microbes sneaking off a contaminated lander. “ This fellow was a very interesting writer, but I think he is also being shortsighted in thinking that there may be a type of life that may indeed be able to survive that intense blast of UV radiation. The deeper we dive into the world of life in extreme environments and begin to apply our findings there to astrobiology it becomes easier to imagine a broader definition of the requirements of life."

primordial soup
self replicating RNA
RNA timeline
Week 6:
project based learning

Buck institute for project based learning

ten extinct beasts that could roam the earth again

ten extinct beasts that could roam the earth again


this is a great reference article to use in the science classroom. Genetics, ecology, biotech, ethics, Great stuff

about time

even if everything has not gone as smooth as we thought, this is worth it!




we want our money back and we're gonna get it!