Category Archives: biology

There Was A Mighty Duel!

I live in an old neighborhood and my building is a very old edifice of wood, stone, and tar. There are lots of nooks and crannies, rusty tin things, and overgrown thickets of weeds. Perfect ecology for tiny creatures and things that make me go “HOLY FUCK, GET AWAY!”

But these two guys were much too preoccupied with an epic battle to try and frighten me. It was a shock to come across this scene: an itty bitty spider and a fat ol’ beetle, locked in an epic struggle of survival. They are still going at it as I write this. Last I saw, Spidey was punching Scarab in the face, and poor old Scarab was crying (I swear I saw tears; the dude was wet, and this area hasn’t had any rain). I took a couple still photos and a couple 30-second movies with my Fujifilm FinePix S700.

They were kung-fu fighting!

Creeped out, but I could not. Walk. Away.

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In which my inner nerd comes out to play

Science alert! If you are utterly disinterested in the world around you, don’t bother to read this post as it will undoubtedly bore you.

I love evolutionary biology and genetics. The intricacies of life never cease to fascinate me, so when I read of studies like this I am so filled with wonder and excitement that I want to share it with everyone. To sum up this link for those of you not inclined to read it themselves (tsk tsk), this experiment, conducted over the course of 20 years, provided supporting evidence to Gould’s hypothesis of evolutionary contingency, in which he puts forth the idea that

…if the tape of life were rewound to the time of the organisms found in the Canadian outcrop known as the Burgess Shale, dated to about 530 million years ago, and replayed with a few contingencies tweaked here and there, humans would most likely never have evolved (source link here).

In other words, Gould suggested that you cannot re-evolve the same end result from the same starting point.

This particular experiment took 12 colonies of identical E. coli bacteria and let them flourish in identical environments for 20 years, or 40,000 generations. Every 500 generations a sample from each of the 12 colonies was frozen, to be thawed out and to resume growth at a later date, for comparison.

At around generation 31,500, something interesting happened. From the article:

After about 31,500 generations, one colony of bacteria evolved the novel ability to use a nutrient that E. coli normally can’t absorb from its environment. Thawed-out samples from after the 20,000-generation mark were much more likely to re-evolve this trait than earlier samples, which suggests that an unnoticed mutation that occurred around the 20,000th generation enabled the microbes to later evolve the nutrient-absorption ability through a second mutation…In the 11 other colonies, this earlier mutation didn’t occur, so the evolution of this novel ability never happened.

“I would argue that this is a direct empirical demonstration of Gould-like contingency in evolution,” Lenski [the lead researcher] says. “You can’t do an exact replay in nature, but we were able to literally put all these populations in virtually identical environments and show that contingency is really what had occurred.”

The next step will be to determine what that earlier mutation was and how it made the later change possible, Lenski says. If the first mutation didn’t offer any survival advantage to the microbes on its own, it would make the case airtight that Gould was right. That’s because a mutation that doesn’t improve an organism’s ability to survive and reproduce can’t be favored by evolution, so whether the microbe happens to have that necessary mutation when the second evolutionary change occurs becomes purely a matter of chance.

“I don’t think they’ve necessarily shown” that the first mutation gave the microbes no survival advantage, comments Christopher Dascher, a microbiologist at Mount Sinai School of Medicine in New York. “But they certainly point very strongly in that direction.”

Lenski notes that the growth rate and the density of bacteria in the colony jumped up after the second mutation, but not after the first one.


This is the statement that gets me excited:
“a mutation that doesn’t improve an organism’s ability to survive and reproduce can’t be favored by evolution, so whether the microbe happens to have that necessary mutation when the second evolutionary change occurs becomes purely a matter of chance.”

I know its completely nerdy and geeky of me, but I find this to be totally awesome. And a definite rejection of the creationist assertion that there is no proof of evolution in science. So to those individuals, I say “take that!”

Mad Scientist

I find myself without a thing to say, staring at that picture of Dexter, wishing I still had that mad scientist costume I made in his honor. I’m thinking that if I were smarter, I totally could have been a mad scientist; I have come up a few wacky ideas. To wit:

  • Appetite suppressant: A few years ago, I contracted Mononucleosis. The first month I had no appetite whatsoever–I forced myself to eat soup, pudding, and toast when I was able. The next two months, my appetite gradually increased to half it’s normal levels, to where I was eating two medium sized meals a day: a bowl of cereal and some juice for breakfast, and half a plate of spaghetti for dinner, for example. I dropped 30 pounds in those months, from 185 to 155. Now, three years have passed, and my appetite is completely, utterly, back to where it used to be before I became sick. In the last year and one half, I have gained 15 pounds, a depressing 170 pounds. This leads me to wonder how I can get back that naturally occurring loss of appetite without getting so horribly ill. Suddenly, it came to me! If we could extract that part of the viral DNA/RNA that induces appetite loss and embed it into the genome of a bacterium that is harmless to humans, could that work as an minimal-side-effects-weight-loss-pill? Yes, I know that loss of appetite has more to do with the effect of one’s immune system working against the invading infection, and not a consequent of foreign DNA, but still–if a virus or bacteria could be found to directly impact hunger, than could not its DNA be incorporated into a “magic obesity cure”?
  • Cybernetic Prostheses: (I have no idea when or how I came up this one, but come up with it I did, when I was but a teen) Taking the idea of the cochlear implant a step further…We should combine nanotechnology, biochemical engineering, and stem cells (the stem cells part is a recent addition to this mad scheme) in the production of fully-functioning prostheses for amputees. Somehow the combination of all three technological elements should create a synthetic nerve network that can interact with the recipient’s natural central nervous system. The joint between the amputated limb and the prosthesis would be made of surgical quality stainless steel bolted into the bones of the recipient and artificial nerves, blood vessels, muscles, and bone would interlace and interface with the biological counterparts. The idea is that the artificial nerves would be able to communicate naturally with the biological nerves, thus rendering control of the prosthesis unconscious, as if it were a natural limb.


That’s all for now. Its late, my honey is home, and I want to cuddle. I’ve got a lot of other crazy ideas, not all of them scientific. A lot are entrepenurial (such as a Arts Intstitute, a World-Cuisine resturant for Dieters, and a Fun and Games Center complete with tri-level mini-golf). Maybe I’ll talk about those ideas later. But now, I’m going to go give my honey a hug.

Apparently, it was inevitable.

I’ve always had a passion for genetics. If I were smarter at math and had the patience for tedious research, I’d probably be an evolutionary geneticist, looking at microbial and viral epigenomes and geneomes. (Probably testing my pet hypothesis that viral genetic deposits–i.e. “junk dna”– have a greater impact on evolutionary processes than we heretofore supposed. Probably especially with the influence of the epigenome. ) So I am always excited to read on discoveries in the genetic fields.

Naturally I found the discoveries of the Woolly Mammoth’s genetic extinction quite fascinating.According to the genetic evidence, the woolly mammoth was already in a state of terminal decline when humanity began to hunt them for meat. At one point, the populations diverged into two distinct genetic lines, and later re-merged. One of those lines went extinct before the other, and the remaining line began to show signs of decline. The conclusion: the great mammoths would have gone extinct anyway, regardless of humanity.

This made me think of modern endangered animals, particulary the Giant Panda and the Cheetah. Everyone knows the panda would rather eat bamboo than mate or rear offspring, and the cheetah, sadly, has too little genetic diversity left. It seems extinction is inevitable for these species. Shouldn’t we just let it be, enjoy them while we can, and expend our energies on reviving the populations that actually can be saved?

I’m open to debate.
Rachel

Weirdness

Ever since I’ve started working out (its been about a week or so) and eating more plants, I haven’t wanted chocolate so much anymore. Last time I had chocolate was Monday. Yummy gooey lava cake! Oooo…..
Anyway, even now, when I’m thinking about it, I have a desire to taste it, but not that overwhelming need. Two weeks ago, I was LIVING for chocolate, eating a least a candy bar every day. And if I needed chocolate I would pace the house until I found some. But now, that need is ebbing away. Its weird: I’m in the middle of my PMS and normally I’d be craving chocolate and feeling cranky. Instead I feel fine. Looking forward to eating my rice noodle salad for lunch. Going to the gym tonight, gonna walk and run for a while. Maybe all those endorphins from exercize are replacing the effect the chocolate has. (Here’s some trivia: did you know that chocolate has trace amounts of THC–the active
drug in marijuana–in it? No wonder I always crave potato chips after eating a milky way.)
If I could remember where I found that source I’d post it….I’ll look for it, and post it in an edit when I find it.

PS: okay I did some internet reading. I must correct myself. Chocolate does not contain THC. It has a bunch of happy chemicals in it, but the one that I was thinking of is lipid anandamide which is chemically similar to THC and activates the same receptors. Here’s the link! : http://serendip.brynmawr.edu/bb/neuro/neuro04/web1/kcoveleskie.html

Lilacs

I’ve always liked lilacs. They have a sweet and heady scent that never
fails to make me feel happy, like all is well with the world.

I was reading the life section of the local newspaper (www.rep-am.com),
and there was an article about an upcoming lilac show. I was surprised
to learn that they have 15 varieties of liacs. I thought there were
only the purple and the pinkish-white that I grew up with.

Then I go online and find out there are over a THOUSAND varieties of
lilacs!
http://www.gardenersnet.com/lilac/lilac04.htm

Not only that, lilacs come in all different colors and arrangements.
http://lilacs.freeservers.com/petalsandcolors.html

For descriptions of specific varieties, go here:

http://www.ipm.iastate.edu/ipm/hortnews/1995/5-26-1995/lil.html

After learning all this, I noticed that there are lilac bushes growing
everywhere in these parts. And I noticed they WEREN’T what I beleived
them to be. Here in Connecticut, the lilacs are lavendar or white or
pink, not the deeper purple or pale pink I am familiar with, growing up
in the Mountian West.

I am amazed at how ignorant, and how unaware of that ignorance I was. I
suppose it just goes to show how our beliefs and ignorances can cloud
our perceptions, leading us to see only what we are capable of seeing,
or preventing us from seeing what stands before us.

Kevin Trudeau’s "Weight Loss Cure"

Lately, they’ve been showing early-morning infomercials selling Trudeau’s book. He makes a very passionate case trying to sell it, talking about governmental oppression, etc. etc…

I am dubious of wild claims and impassioned oratory, especially when such is made in the pursuit of money. So I went online and did some research.

First, I went to amazon.com to read reader reviews. Found out the miracle cure has something to do with “hCG”. I googled “hgc weight loss” and that led me to this website:

http://hcgobesity.org/

I read their articles, and here is the gist of it all:
Seems that Trudeau is hyping a treatment “discovered” by a Dr. ATW Simeons in 1954, consisting of daily injections of the hormone human choriogonadotropin (HCG, brand name Novarel), which is normally used to treat female infertility and undescended testes in males.

Apparently, the weight loss protocol described by Trudeau consists of a daily dose of diluted HCG (oral or injected) AND a 500 calorie diet, and requires daily monitoring by a trained physician. Further, it seems that HCG does not affect adipose subcutaneous fat directly (both camps agree on this point)–the weight loss is a result of the restricted caloric intake. Hypothetically, HGC’s role in the diet is to regulate mood and appetite, and increases fat mobilization (I take that to mean it encourages fat burn). The research on those claims regarding HCG’s role is controversial and incomplete. The FDA says that the available research shows no significant impact upon weight loss. Proponents say the FDA’s conclusion is based on flawed research that relied on measures of total weight loss rather than actual fat loss. They present research that claims an actual statistical diffrence in total fat loss, measuring actual levels of subcutaneous fat rather than a person’s total mass. In rebuttal, impartial researchers claim that an analysis of all the research shows no evidence of “fat distribution” “caloric mobilization”, or “appeitite suppressing effects” of any statistical significance. I also noticed that the research used to support their claims has a sample size that’s quite small: at the end of the study, only 5 subjects received the placebo, and only 8 received oral hCG. That makes me doubt the statistical validity of the results.

Here are some sources (all links full of pharmacological technobabble):

For the pro-hcg side:
Here’s the offical website:
http://hcgobesity.org/ifcor/introduction.htm

Here’s the study mentioned above:
http://indexmedico.com/obesity/hcg.htm

And for the anti-hcg side:
Here’s a critical overview of all the claims:
http://www.dietscam.org/reports/hcg.shtml

And this is the impartial review of available research on the topic:
http://www.crd.york.ac.uk/CRDWeb/ShowRecord.asp?View=Full&ID=11995002683

There ya go: the “weight loss cure” is an overhyped starvation diet of dubious, unsubstantiated worth.
Don’t buy the book.
Rachel