Category Archives: biology

#hopejahrensurecanwrite

I discovered Hope Jahren and her writing via Twitter a few years ago, before she even had a blog. Instantly hooked, I added my voice to the rising chorus of #hopejahrensurecanwrite urging her to start a blog so we could get more from her virtual pen. I am constantly blown away by the astonishingly precise emotional power of her writing.

As you may have heard or read, Hope Jahren has a new book out, one that had even the notoriously hard to please Michiko Kakutani gushing praise at the New York Times, comparing the precise poetry and scientific imagination in her writing to that of the late great Oliver Sacks and Stephen Jay Gould! Other reviews of “Lab Girl” are unanimous in saying that Jahren’s writing will change the way you look at plants and at the world of science and nature.

My own amazement at plant lives, shaped in some part by Hope Jahren, has been exploding in recent years, as I read more about the astonishing things we continue to discover about their far from dull lives. Just this past week, I found myself urging my Intro Biology students out of their post-lunch lethargy by telling them to contemplate the life of a plant. Boring… they responded, before I started telling them about some of the incredible things plants do. Luckily, I had this passage from Lab Girl to read to them:

“It might strike you as fantastic, but you really can hear plants growing in the Midwest. At its peak, sweet corn grows a whole inch every single day and as the layers of husk shift slightly to accommodate this expansion, you can hear it as a low continuous rustle if you stand inside the rows of cornfield on a perfectly still August day.”

And today, when we start the unit on Fungi, I expect to share this gem of an observation:

“You may think a mushroom is a fungus. This is exactly like believing that a penis is a man.”

Somehow I was one of the lucky ones to receive an advance reader’s copy of Lab Girl, and have been meaning to write a review here. But this post ain’t it. Fan as I am of Hope Jahren’s writing, her book landed in my mailbox smack in the middle of the semester in an exceptionally busy and stressful year. I’ve started the book, but haven’t finished it yet, for… reasons…

I get the feeling that I may have pulled back from Hope Jahren’s book just a bit mainly as a perhaps misguided attempt to protect my time for things I must get done. And I don’t mean that Lab Girl isn’t something I must read – in fact I feel quite the opposite, that this book is more important than anything else right now, and therefore is something I must finish before anything else; and paradoxically, given the urgencies of other things, I’m forced to delay the gratification of immersing myself in this fantastic book because I have chores to finish. Why must one deny oneself such simple pleasures as reading a richly complex thing? Poorly structured procrastination? Lame excuse, I know, but I will allow myself to be swept away by Lab Girl very soon…

Meanwhile, my teenaged daughter S has swooped in and is devouring the book, savoring it slowly and reading particularly well-turned phrases and passages out loud to me from time to time. A budding writer herself, S delights in being swept away by Hope Jahren’s tales. After telling me more about it this weekend, and asking me how I could keep from finishing reading this book, S asked me to reread another thing which is her favorite from Jahren’s amazing blog: her open love letter to millennial women, which contains such passages as this:

“I finally understand why my mother was so adamant that I should not pierce my ears. Us old ladies have been disappointed to find that we are not so different from our male masters after all, when fear rotted our love into control. Your freedom terrifies us. In our day, if you admitted to being a lesbian, men tried to rape it out of you. For us, forty years of financial safety pragmatically trumped romance, and rendered purity before marriage one of many survival techniques. I struggle and hold my tongue, knowing deep down that you know best how to live in the world that you are creating. When you have time and pity, you are teaching me. You are better with people than I’ve ever been, naturally friendly and sweet.”

And this:

“Watching you from a distance, I like to think that you were born of the pain of my generation, of our punitive divorces and meager unfair paychecks and deadly IUDs. You are the precious daughters of the Revolution that we wanted, and of the broken-parts-missing Revolution that we got. When I am old and sick and ugly it will comfort me to know that you are the ones running the world.”

Indeed. Go read the whole love letter. Now. And then read the rest of her blog and bookmark it and add it to your RSS feed or whatever other device you have for keeping up with blogs. And buy and read her book “Lab Girl“.

Because you know what?

#hopejahrensurecanwrite

Ooze like an amoeba, float like a bird – wish we could still do that when stressed!

Here’s another fun weird science story from NPR, about a creature that might be in the dirt in your own backyard:

20100305 Me 03 by Npr
Download now or listen on posterous

Naegleria-NPR.mp3 (1426 KB)

Naegleria gruberi

Courtesy of Lillian Fritz-Laylan
Naegleria gruberi grows a pair of flagella when under stress. But unlike a sperm tail, it puts these appendages out front, and swims by breast stroke. The organism is stained to emphasize its anatomy.

If you prefer to read the story rather than listen to it aloud, here’s the transcript via npr.org.

ResearchBlogging.org

While that behavioral and morphological flexibility is remarkable enough in something we might, from our lofty hominid perch, consider rather “primitive” and “simple”, what graduate student Lillian Fritz-Laylan and colleagues found in its genome is perhaps even more surprising. Whle the NPR story focuses on the physical transformation of the organism, cool as that is, the full story is much richer and has far more significance for our own origins from a common eukaryotic ancestor. As they describe in their paper in the current issue of Cell, Naegleria gruberi turns out to have almost 16000 protein-coding genes, which is over two-thirds of what you and I have! A single celled organism with that many genes – no wonder it can transform itself so radically.

Here’s an image from the paper illustrating that transformation, which takes a mere 90 minutes or so (far cooler special effects at half the duration of Avatar, if you ask me!):

Figure 1: Schematic of Naegleria Amoeba and Flagellate Forms. Naegleria amoebae move along a surface with a large blunt pseudopod. Changing direction (arrows) follows the eruption of a new, usually anterior, pseudopod. Naegleria maintains fluid balance using a contractile vacuole. The nucleus contains a large nucleolus. The cytoplasm has many mitochondria and food vacuoles that are excluded from pseudopods. Flagellates also contain canonical basal bodies and flagella (insets). Basal bodies are connected to the nuclear envelope via a single striated rootlet. 

Is it just me, or does that upper image, of the amoeboid form, remind you of someone? And… I just realized… that someone also has two apparent flagellae at the top of his head, which unfurl during times of stress!! What better proof do you want of our shared ancestry with Naegleria, eh? No? Oh, what – you mean citing widely published and viewed cartoons is not good enough evidence for you (even though that is a standard of evidence good enough for a third of the good people of Texas)? You want all the boring science-y stuff instead? Well, go read the paper then, which the journal Cell has graciously made freely available!

The paper (luckily for you) turns out to be far from boring. It is indeed quite fascinating because, apart from presenting the complete genome sequence of this remarkable free-living protist, Fritz-Laylan et al also describe several genetic modules for aerobic and anaerobic metabolism (for these guys can do both), amoeboid motility, and a number of other structural and functional necessities of the ecologically diverse lifestyles common to their clade. Further, comparisons with genomes of other protists allow them to predict which genes might have been present in the genome of the common ancestor to all eukaryotes. As the first representative of a fifth (out of 6) major clade of eukaryotes whose genomes have been sequenced thus far, Naegleria holds great promise of generating fresh insights into the early evolution and diversificatiion of eukaryotes. While their lineage diverged from the one we hail from about, oh, a billion or so years ago, understanding their genome brings us closer to understanding and reconstructing the genome of our shared ancestors, those early free-living eukaryotes that gave rise to us both. For it turns out that they contain over 4000 protein families that are similar to ones we have, and therefore were likely found in that common ancestor! That ancestor was presumably also quite versatile and equipped with a set of flexible modules to deal with the diverse environments of that time. And that remarkable flexibility probably underlies the extraordinary diversity of organisms that subsequently evolved from that ancestor. How fascinating and wonderful is that! (Even if some of us later lost the ability to transform ourselves and float away when under stress!)

Let me end with a video where the lead authors talk about what Nargleria‘s genome can tell us about our own ancestry:


Reference:

Fritz-Laylin, L., Prochnik, S., Ginger, M., Dacks, J., Carpenter, M., Field, M., Kuo, A., Paredez, A., Chapman, J., & Pham, J. (2010). The Genome of Naegleria gruberi Illuminates Early Eukaryotic Versatility Cell, 140 (5), 631-642 DOI: 10.1016/j.cell.2010.01.032

The immortal HeLa cells and their source, Henrietta Lacks

ABC World News aired this story last Sunday, which includes a short interview clip with Rebecca Skloot, whose book The Immortal Life of Henrietta Lacks is just hitting the stores. And yes, the woman’s name is Lacks – but lame as it seems, the ABC website and video have misspelt it!! The story itself is quite remarkable, and really well told. I will try to post a review of the book here as I’m hoping to finish reading it soon.

Posted via web from a leaf warbler’s gleanings