Redefining the concept of organism

Staph PlateA while back, I stumbled upon an article by Freeman Dyson on Carl Woese. Carl Woese is a long time scientist studying the origins of life and revolutionized thinking around early life, microbiology, and phylogeny.

Freeman Dyson's article is a great overview of the discussions around pre- and post-Darwinian evolution*. Darwinian evolution is what we are used to, a standard "fight for survival" of non-interbreeding species that slowly evolve their fitness to the challenges in the environment.

What really flipped me was Dyson discussing pre-Darwinian evolution, an idea postulated by Carl Woese back in 2004 in an article titled "A New Biology for a New Century." The thought is that early life was a time of promiscuous gene swapping. That, as I see it, an organism was a sack of molecules and genes that worked together to propagate a collection of "features." Then, at some point (Woese suggests at least three) an organism stopped, found a good set of genes, and brought this lateral gene transfer down to a trickle. And there you have a "species."

The three times Woese mentions were the times that gave rise to Archaebacteria, Bacteria, and everyone else. This free mix and match with a sudden stop makes sense of why there are three large groups of cell structures, yet that they are related in some way.

This idea really hit home for me when listening to Penny Chisholm, a microbiologist, talking about Prochlorococcus on Science Friday. This small cyanobacteria might be the most abundant photosynthetic organism, but Chisholm and colleagues only discovered it in the 80s.

What was interesting was her answer about different species of Prochlorococcus: she called them "genomic variants."

This ties back to what Woese was implying about lateral gene transfer and pre-Darwinian evolution and sacks of organisms with a collection of genes. If all organisms are in the possibility-space of all arrangements of genetic elements, then a particular strain of organism would be a peak of variation in that particular area of arrangement of genetic elements (but still part of a continuum of possibility-space).

Micro-organisms still do a lot of gene transfer (witness the spread of antibiotic resistance across species). But I suppose at some level they mix up everything and can have a large amount of variation across a single species. Hence, Chisholm's observation that Prochlorococcus species are best viewed as variants than distinct species. Promiscuous lateral gene transfer across Prochlorococcus "species" deflates the definition of species as non-interbreeding organisms.

As microbial biology has a renaissance due to the rise of synthetic biology (humans effecting lateral gene transfer in micro-organisms at a scale we haven't done before), understanding "speciation" in terms of "genetic variants" will go a long way in understanding how and what genes are to be used.

*Dyson also compares the way cultures laterally transfer as the post-Darwinian era.

Image from If you dream it…

Funny story about common chord progressions

I read this funny article about how the ‘Sensitive Female Chord Progression’ has infiltrated so many songs.

Link: Striking a chord – Boston Globe

Even though Beyoncé’s “If I Were a Boy” hit radio too late to be the
song of the summer, there’s still a case to be made that it’s the
perfect song to cap off the year. It’s not because of the empathetic
lyrics, or B’s heartrending, disappointed vocals. No, it has everything
to do with the four chords that underpin the song’s verse, circling
from yearning to triumph and back again, four chords that were
inescapable in 2008.

While some of the comments were snooty, there was a great link to the video below – a comedian talking about how Pachabel’s Canon in D has hounded him his whole life.

Help NPR plan their social media activities for the US presidential inauguration

Cool. Via Perry Hewitt.

Link: NPR: Help NPR Plan Our Social Media Activities for the Inauguration:

Help NPR Plan Our Social Media Activities for the Inauguration

The presidential inauguration is less than a month away and the NPR social media desk is kicking it into high-gear to figure out how we can get all of you involved in our inauguration coverage. We're also looking for some techies who can help make it happen.

At least I like some of the predictions RWW made for 2009

Yup. Yup. And yup.

“One word son: filters.”

2009 Web Predictions – ReadWriteWeb.

– Apps that do filtering, inferring and recommendation have a great year; several will release plug-ins for Google Reader, Twitter, Facebook and other ‘sipping from the firehose’ apps.

– New real-time web app launches that integrates Twitter, FriendFeed & more in ways we never could have imagined.

– More contextual browsing technologies will hit the market powered by improved top-down semantic recognition engines.

Phylostratigraphy: Genetic Archeology

Strat
The Economist reports on some scientists that did some phylogenetic comparisons to see when certain genes arose. The scientists noticed that genes that appeared earlier in evolution are more likely to be disease genes than genes that arose later in evolution.

For some reason, the writer for the Economist suggests that older genes would have had more time to evolve any disease away. But, on the contrary, I suggest that older genes are more fundamental and therefore more prone to be involved in diseases. Though I am not sure sure why the scientist found that "genes specific to mammals, by contrast, barely ever carry diseases." Surely there are genetic diseases that revolve around brain genes foud in humans. But it could be even those genes go far back in time.

Nonehteless, the word "phylostratigraphy" is damn cool.

Link [via @preoccupations]: Genes, disease and evolution | Bad old genes | The Economist

As they reveal in a paper in Molecular Biology and Evolution, the researchers found that the majority of disease-causing genes were present in single-celled organisms and that most of the rest arose when multicellular creatures began to evolve. Genes specific to mammals, by contrast, barely ever carry diseases.

Image by Stephen Witherden

Presidential DNA tested for 2012 election?

Wow. This is a deep topic. While I think the discussions around DNA testing will start raging in the next 12 months, for sure there will be a question of whether presidential candidates should have a DNA test as part of the public health report.

Ho-boy, this is getting interesting.

Link: Presidential DNA: Don’t Ask, Don’t Tell? : The Personal Genome

The next presidential candidates will face an electorate that is radically more conversant in and curious about DNA than ever before. We should reasonably expect that the presidential election of 2012 will include, for the first time, requests for candidates to make their genetic information part of the public record.

A wander through personal genomics

ChromatinSo, I’ve been talking about trends in biology that I think are significant (maybe because I’ve only started following biology again in the past year). In any case, I’ve said the trends were synthetic biology, the future of scientific publishing, and personal genomics.

Personal genomics is where individuals have detailed access to their genomic information (your genotype). To put us all on the same page, your genome is the totality of all your DNA – your nuclear DNA and your mitochondrial DNA. I claim that it also needs to include your micro-organismal biota DNA, as well. But, what the genomic information gives you is the programmatic basis for who you are, where you’ve come from, and what you might pass on.

Genetics 101

To be frank, you already have a clue as to what your genotype is, through observation of your phenotype (how your genotype is expressed in an observable attribute). For example, if you have blue eyes and only one of your parents do, you know that the non-blue eye parent is carrying a blue-eye gene (in normal cases, of course, but you get the idea). Indeed, the long list of questions of parental and family history that doctors ask are a sort of genetic profiling to give an idea of your own hereditary susceptibility to diseases.

Knowing all your DNA code at this time (through sequencing) is unlikely, mostly due to cost (unless you are on this list, or this program, or are this guy). Sure, it will come (and on the way, someone will win a prize). But for now, you need to be satisfied with just the direct sequencing of known stretches of DNA.

Another way is to look for indicative SNPs (pronounced ‘snips’, small nucleotide polymorhphisms, basically differences in code at a certain position of the genome). These SNPs are used as markers associated with a gene or phenotype. Hence, knowing SNPs, which are easier to scan for than sequencing the whole genome, are the state of the art in whole genome understanding.

Booming area?

While the dream of personal genomics is to drive more targeted pharmaceutical treatments, I think where it will really boom is in giving people their information to do what they want to.

I have seen a few companies pop up that offer various forms of DNA tests for regular folks, for curiosity or what. It definitely sits in a general self-knowledge, self-measurement trend that new sensors and tools have begun to provide.

One company I have been following is 23andMe (a play on humans having 23 pairs of chromosomes). In a nice twist, the genetic testing (they scan one million SNPs) is really just a conversations piece, a social object that customers discuss on 23anMe’s socially-driven service. Yep. Social sharing meets biological diagnostics.

How much can it cost? 23andMe used to charge about $1000 per test (and I think that was for 500k SNPs). Recently they lowered the price to $400 and cover over one million SNPs. I suppose, at some point, the price will level off to ensure business profitability. Well, so long as profitability is based on selling tests. Which I probably suppose it won’t be, since these are smart folks running the company.

Thoughts on this

While I am still trying to get a feel for how 23andMe is positioning itself, I do think that the drive in personal genomics will come from people wanting to know more about themselves, to help them make lifestyle decisions, and to feel more secure about their potential health future and of their children. And having the information before knowing what it means is fine, since companies like 23andMe keep combing the literature to add meaning to the data.

Also, pulling on the self-quanitification thread, one might want to marry this with other whole-organism tests. Metabolomics, the sum total of your metabolites, gives a great understanding of your current physiological make up. Marry a string of metabolic analyses with the understanding of your genome, and you have a powerful whole-body understanding. And metabolomics is a mature field with a good technological and informatics underpinning. And it is not expensive.

And and and, what’s more. If you think of the genomic data 23andMe are sitting on, they stand a lot to gain from adding further info to the genomic set. They are already doing surveys that they can match to customer genomic profiles. Imagine if they had detailed metabolic information? Then they have a powerful repository of information to mine about health and genetics. Ripe enough to make oodles of money on, without violating anyone’s privacy.

Hm.

Image by Image Editor

Potential of immune system reboot?

This is cool (below). Gene therapy combined with a re-install of the immune system.

I am writing a story where the main character basically gets an immune system reboot. Due to the longevity of the people in the story, they are more susceptible to auto-immune diseases as the immune system breaks down or goes awry. Therefore, folks get regular immune system resets and required re-immunizations.

I know someone who is over 80 and is healthy except for an auto-immune disease that he got in the past 5 years. A reboot would cure him. Right?

Link: The Spittoon » Very Personalized Medicine: Genetically Customized Bone Marrow Transplant May Have Eradicated Patient’s HIV

The doctors reasoned that if they could find a donor who was not only immune compatible with their patient, but also had two copies of the Delta32 mutation in the CCR5 gene, perhaps they could simultaneously eradicate his leukemia and his HIV infection.

Remarkably, such a donor existed. And 600 days after his bone marrow transplant, the patient is both leukemia- and HIV-free.

Hm. Just noticed changes in Google Search

When was the last time Google messed with their search page? Seems like in this past week’s big push (they killed Lively and made changes to Gmail) they seemed to have added some controls to their search results (or at least, as suggested below, I finally got to see it).

There are promote and remove buttons and a comment button. Has the GOOG finally realized that robots can’t do it all?

This feature has been getting rolled out for a while (a report from Read Write Web). And it seems to me that it actually is something personal, rather than publicly shared. Though it’s probably one more, "use it privately and we aggregate and data mine it" (like Gmail).

I think this is a big thing for Google.

A good warning for writers, by Joel

Another great article by Joel Spolsky on, basically, literary laziness.

Link: Anecdotes – Joel on Software

This is not the way to move science forward. On Sunday Dave Winer [partially] defined “great blogging” as “people talking about things they know about, not just expressing opinions about things they are not experts in (nothing wrong with that, of course).” Can we get some more of that, please? Thanks.