Byte Size Biology

I have written about the Journal of Serendipitous and Unexpected Results before and now this just popped in my inbox from JSUR’s Google group. Apparently JSUR is now open for business.

JSUR Call for Participation

Submit your short (2-4page) and full length manuscripts to the Journal
of Serendipitous and Unexpected Results.

Over the past month we’ve received a great amount of press and
publicity for the Journal of Serendipitous and Unexpected Results
(JSUR). Thanks to everyone who helped spread the word, please keep it
up!

In Richard Feynman’s 1966 Nobel Lecture, he said, “We have a habit in
writing articles published in scientific journals to make the work as
finished as possible, to cover up all the tracks, to not worry about
the blind alleys or describe how you had the wrong idea first, and so
on. So there isn’t any place to publish, in a dignified manner, what
you actually did in order to do the work.”

We’re writing to invite you to solicit short (2-4page) and full length
submissions to JSUR.  Why not prepare a 2-4 page writeup discussing
side-investigations, alleyways, or false-starts in your latest
published or unpublished research? Papers of this length place a
minimal burden on the authors, while providing extremely valuable
research insights to a broad audience.

Journal website: http://www.jsur.org

Sincerely,
The JSUR Editorial Board

Yes! Why should the evolution people have all the fun with their blog carnival? (After all, it is only a theory.) It’s time for bioinformaticians to show what we are made of, and to have a carnival of our own. Bio::blogs had a good run some time ago. I decided to reconnect what is hopefully now a larger and more networked community under the title of Bioinformatics Blog Carnival.

Northampton: monument to Francis Crick, born in Northampton. Copyright Ian Rob, licensed for reuse.

Programming

For many new bioinformatic programmers, there is a question of which Bio* package to choose from. The Bio* packages (Biopython, BioPerl, BioJava and BioRuby) are open source licensed packages which are used heavily in bioinformatics coding. They contain parsers for bioinformatic data file, file format converters, SQL interfaces and other goodies that make a biohacker’s life manageable. Walter Jessen presents a rapid-fire no-nonsense review of Open Source Programming with Bio* Libraries on Expressing Scientific Insight. Finally, if you would like to do everything wrong, Manuel Corpas presents 10 Sarcastic Rules on How to Be a Bioinformatician posted at Manuel Corpas’ Blog.

Databases

Morgan Langille talks about BioTorrents – a file sharing resource for scientists posted at his blog Beta Science. My take on BioTorrents is that it is a cool idea, but as most institutes block BitTorrent along with other peer-to-peer sharing utilities, I doubt there is a critical mass of feeders to make BioTorrents viable. Things can change though: institutes might decide to set up dedicated servers to Torrent scientific data, just like there are legitimate Torrent servers for Linux distros. George presents Bio-graphics, BioSQL and Rails part 1 posted at Biorelated. He talks about how to quickly add graphics support to a bioinformatics database rails application.

Brad Chapman’s Blue Collar Bioinformatics is a treasure-trove of useful bioinformatics methods. Brad is very thorough in his writing, and he covers a wide variety of topics. I particularly enjoyed reading about his adventures at the biohackathon 2010 in Tokyo, and the resulting Python query interface to BioGateway SPARQL endpoint and InterMine.

Genomics

Nick Loman from Pathogens: Genes and Genomes gives some excellent tips for de-novo genome assembly. He also gives the necessary scripts,which are great companions to Velvet, the popular short read assembler. Luke Jostins writes about AGBT: Speculating on Third Gen Tech posted at Genetic Inference, “An investigation into what data from various third generation sequencing technologies may look like.” SM presents Resources for Exome sequencing annotation posted at Organizing the Strands of Curiosity.

Structural biology

Sean Seaver talks about the retraction of several protein structure papers published by one group at the University of Alabama, Birmingham. Structuregate was reported both in the media and in the blogosphere. Sean walks us through how it might have been done, and how structural bioinformatics techniques found out the wrong structures in Origin and Orientation posted at P212121. Maria Hodges talks about how difficult it is to explain structural genomics to the man in the pub. Menachem Fromer presents Tradeoff between stability and multispecificity in the design of promiscuous proteins. Promiscuous proteins are proteins which bind different partners (ligands, or other proteins). However, the more partners they are able to bind, the less stable they are, as shown in a series of simulated evolution studies, summarized at Nir London’s Macromolecular Modeling Blog. OK, promiscuity and and a pub. There must be a joke somewhere there.

Credit: Iddo Friedberg & 3D chem for the Anthrax toxin lethal factor image

A common lament among bloggers and other enthusiastic adopters of Web 2.0 technology is the lack of mainstream uptake of these tools by active scientists. A recent report from University of California Berkeley confirmed this: “The advice given to pre-tenure scholars was consistent across all fields: focus on publishing in the right venues and avoid spending too much time on public engagement, committee work, writing op-ed pieces, developing websites, blogging, and other non-traditional forms of electronic dissemination (including online course activities)“. Maria Hodges argues that Web 2.0 thrives where journals don’t, and that the NMR community might be the first to reach the tipping point, where your career is harmed by not contributing. She talks of two wikis used by the NMR community. It is a small community, which has a need for sharing methods that are generally not publishable in peer-reviewed journals. The wiki venue makes for an ideal dissemination method for this community. On the subject of data sharing, and how it can backfire: here is an interesting connection between the history of the PDB, and the email affair known as ‘climategate’.

There are more microbial cells in our body than our own. Those microbes are not just passive hitchhikers or conversely, malicious agents of disease. They affect our well-being and health in a much broader spectrum than simply “bad” or “passive”. Among other things our gut microbes play an important role in digestion, have been linked to obesity, conditions as severe as certain inflammatory bowel syndromes or as relatively mild as traveler’s diarrhea. The microbes living on our skin also affect many things: from body odor and dandruff and acne to dermatitis and psoriasis. Also, being the most exposed microbial population means that they are themselves affected by our constant exposure to various agents,and their population varies by our own behavior –  such as how often, and with what, do we wash our hands: antibacterial soap has been named as a major culprit in the development of resistant bacterial strains. In all organs the native flora, relatively benign, protects us against colonization by more virulent bacteria.

Indeed, our gut, skin, mouth and genital microbiomes can be viewed as  additional organs in the way that they affect us. If you take a long course of powerful systemic antibiotics, the ensuing diarrhea and sometimes mouth thrush are the result of these “organs” — in your mouth and gut — being removed temporarily from your body.

Credit: David Gregory&Debbie Marshall. Wellcome Images images@wellcome.ac.uk

Today, another big step has been taken towards understanding the role of our microbiomes play. Just how big, in what direction, or what will be the consequences of this step is unclear, and will remain unclear for quite some time. A group of Chinese and European researchers have published the largest sequencing effort yet of gut bacteria. Their current yield, 576 Gigabases of DNA from the feces of 124 European people is considerably larger than the previous large effort in the US: 3GB from sequenced from 33 US and Japanese adults. Also, Qin and colleagues looked at obese, lean, healthy and sick (inflamatory bowel syndrome) individuals. They identified 1,000 to 1,100 different bacterial species, with about 160 different species per individual. Healthy individual’s bacterial population was markedly different that those with inflammatory bowel syndromes, and the populations of those with IBS differed depending on disease type.

What does this all mean? Well, like in the human genome project, it will take a while before  we understand not only what these data contain, but what are the limits of our ability to interpret them, and how best they can serve us. What we have right now is the equivalent of the outline of a newly discovered continent. It is up to many individual explorers to discover and chart the myriad living things in terra excreta. Which genes are most associated with obesity or with ulcerative colitis? How prevalent is gene transfer between gut bacteria, and how much of a role does this play in antibiotic resistance? Are there microbial species more prone to changes in their genomes than others? Are there metabolic pathways that are shared between different microbial species? Are some genes faster evolving than others, what would be the ecological role different species play in the gut? And how do different microbial populations ultimately affect their human hosts? Do different bacterial species have a preference with whom they share our guts? These broad questions can be broken down into individual questions relating to a lab’s pet genes, metabolic pathways, microbial species and metabolic conditions. There is a lot to sift through here and these data will keep us busy for years to come.

Pathogenic E. coli on the intestinal lining. Credit: S. Schuller.

In other blogs Carl Zimmer has a great post on how he, for one welcomes our bacterial overlords, while Ed Yong talks about the science of things to come.

Oh, and for those of you who, like me, can’t wait to plug the data into your favorite analysis pipeline, you can get the gene and assembled and annotated sequence data data from Peer Bork’s lab at the European Molecular Biology Laboratory, or the Beijing Genome Institute. The raw sequence data are available from the European Bioinformatics Institute under the accession ERA000116. (I can’t find the latter myself right now, hopefully they will show up in a couple of days). Update March 7, 2010: the sequences are now deposited at EBI. Also, on BioTorrents (hat tip to Morgan Langille).

Some interesting events cropped up recently. The Marco Island Advances in Genome Biology and Technology meeting was heavily tweeted and blogged about.  Pacific Biosciences unveiled their third generation sequencer. Ostensibly, it can sequence reads of 20,000 length, but the fraction of actual long reads in a run, and their quality is still a bit hazy. The most interested to me is the Ion Torrent. Being rather low on budget, this seems like the family budget car of high throughput sequencing: cheap, reliable, and does not offer more than I really need. $50,000 for a sequencer with $500 runs with 160MB/hr? Nice. Genetic Inference has a great summary of the various technologies presented.

Overall, we are starting to see a divergence in sequencing technologies, as each tech concentrates on having clearly defined advantages and potential applications that differ from all others. This means that the scientists themselves can more closely tailor their choice of tech to fit their situation. Are you a small lab that needs 10 high-quality genomes on a budget? Go to Complete. Want a cheap, fast machine for library validation? Use Ion Torrent. Setting up a pipeline for sequencing thousands of genomes? Go Illumina.

The review article on metagenomics I recently published in PLoS Computational Biology (yeah, yeah, shameless plug) already starts to feels somewhat outdated on the sequencing technology front.

Carnival of Evolution #21 the superstar edition is up: check it out. It’s a nice and detailed one,. Some posts I liked included talking about how human fingers evolved, and why it is important to consult evolutionary biologists when making decision about conservation.

An interesting email I got yesterday: PubGet, a search engine for PDFs of scientific articles, is no linked to PLoS. PubGet is a very useful service that gets  you the article PDF immediately, without going through he usual clickeroo via Google,  pubmed, publisher’s gateway, journal gateway and then squinting along the sidebar to find the PDF link. Nice to see that these two are teaming up.

Finally, two reminders. First, Ada Lovelace day, a blogging day celebrating the achievements of women in science and technology is coming up, March 24. Go ahead, pledge and blog! Second, the Byte Size Biology will be hosting a Carnival of Bioinformatics. Quite a few posts have been submitted already, please submit yours, deadline: March 9.

Haiku:

A finer book of

Blog posts the world has not seen

Buy: you won’t regret

The fine print: one of my posts is published in this anthology

To-day we have naming of parts. Yesterday,
We had daily cleaning. And to-morrow morning,
We shall have what to do after firing. But to-day,
To-day we have naming of parts. Japonica
Glistens like coral in all of the neighboring gardens,
And to-day we have naming of parts.
— Henry Reed “Naming of Parts”

To-day we have  Henry Reed’s birthday. Henry Reed, who wrote one of my favorite poems: Lessons of the War. Reed published this poem in the New Statesman and the Nation August 1942. Superficially, the poem is a soldier’s griping in the ill-equipped British army of WWII.  But there is also the dark undercurrent of a man yanked from everyday life and forced to face his own mortality.  Lessons of War has six parts, and it gets more somber as the poem progresses. The “naming of parts” he talks about in the excerpt above is the all-too-familiar experience in basic training: getting to know your personal weapon.

Here is part II: Judging Distances.

LESSONS OF THE WAR

II. JUDGING DISTANCES

Not only how far away, but the way that you say it
Is very important. Perhaps you may never get
The knack of judging a distance, but at least you know
How to report on a landscape: the central sector,
The right of the arc and that, which we had last Tuesday,
And at least you know

That maps are of time, not place, so far as the army
Happens to be concerned—the reason being,
Is one which need not delay us. Again, you know
There are three kinds of tree, three only, the fir and the poplar,
And those which have bushy tops to; and lastly
That things only seem to be things.

A barn is not called a barn, to put it more plainly,
Or a field in the distance, where sheep may be safely grazing.
You must never be over-sure. You must say, when reporting:
At five o’clock in the central sector is a dozen
Of what appear to be animals; whatever you do,
Don’t call the bleeders sheep.

I am sure that’s quite clear; and suppose, for the sake of example,
The one at the end, asleep, endeavors to tell us
What he sees over there to the west, and how far away,
After first having come to attention. There to the west,
On the fields of summer the sun and the shadows bestow
Vestments of purple and gold.

The still white dwellings are like a mirage in the heat,
And under the swaying elms a man and a woman
Lie gently together. Which is, perhaps, only to say
That there is a row of houses to the left of the arc,
And that under some poplars a pair of what appear to be humans
Appear to be loving.

Well that, for an answer, is what we rightly call
Moderately satisfactory only, the reason being,
Is that two things have been omitted, and those are very important.
The human beings, now: in what direction are they,
And how far away, would you say? And do not forget
There may be dead ground in between.

There may be dead ground in between; and I may not have got
The knack of judging a distance; I will only venture
A guess that perhaps between me and the apparent lovers,
(Who, incidentally, appear by now to have finished,)
At seven o’clock from the houses, is roughly a distance
Of about one year and a half.

You can read all six parts of Lessons of the War here.

I’ve been cleaning out my Gmail from attachment-emails recently. (Why do people continue to send me video files when there’s YouTube?) Anyhow, Mickey Kosloff sent me this. In this pic, form meet function, being concise and to the point, as a good grant application should be.

A picture is worth one-thousand study sections

Byte Size Biology will be hosting the first edition of the bioinformatics blog carnival. All you bioinformatics bloggers, submit your entries by Mar 9, 2010 23:59:03  EST. Note the 3 second extension I have already given. There will be no more deadline extensions, I’ve been generous enough as it is. The carnival will be posted here by March 15, 2010.

Any blog posts that have to do with the computational aspects of: genomics, nextgen sequencing, sequence analysis, gene expression, systems biology, ontologies, databases, structural biology, metagenomics, phylogenetics, function prediction and I probably forgot a few other categories so don’t hold it against me, just submit. Early and often. Your own posts and others that you liked. Nothing too old please, 1/1/2009 and later. I reserve the right to be a less-than-benevolent dictator and screen out posts. This applies especially to commercial plugs with no other merits.

Please retweet, reblog, rebuzz and remember:  submit to the bioinformatics blog carnival!

If you have a cool logo for this carnival, email bioinfo.blog.carnival AT gmail.com OhOne and OhToo will pick the winning logo to be displayed on the carnival. Likewise, if you would like to host the next edition, let me know. Do not submit posts by email, only via blogcarnival.com.

Happy carny-ing.

This has been going around the intertubes for a while now. Still very cool.

As part of the process of manufacturing  a new car,  the designers will take the blueprints to the factory floor. There they will set up an experimental assembly line, tinkering with the manufacturing process of the prototype until it is ready for mass-production. Can we do the same with the machinery of life – the assembly of proteins? Can we set up an alternative assembly line for a new protein prototype — and then actually set up a working assembly line for the whole new protein?  A proof-of-concept has been published this week in Nature by Jason Chin’s group at the Medical Research Council Laboratory of Molecular Biology, Cambridge UK.

If there is a single common denominator to all life, it is the genetic code. All life is built around DNA encoding information for proteins  nucleotide triplets or codons. Since there are four types of nucleotides (A,T,G,C)  that are read in words of thee, there are 4³ = 64 possible codons: more than enough to encode for the 22 amino acids that make up proteins. There is nothing more basic and fundamental to life on Earth than the three-letter based genetic code.

Until now.

Chin’s group has created a four-nucleotide codon system.  It is not that the DNA is different: it is the way the cellular machinery decoding  RNA transcripts interprets the nucleotide sequence. Ribosomes –large RNA and protein complexes  which are the platform upon which messenger RNA is read and decoded — are set to serve up messenger RNA three nucleotides at a time. (Messenger RNA or mRNA is a transcript of the DNA which is carried to the ribosome.)  Transfer RNA or tRNA is a short RNA molecule that shuttles the proper amino acid to the ribosome, but will only attach if the proper codon is served up by the ribosome. The whole protein synthesis “assembly line” looks something like this:

Protein synthesis. Credit: Wikimedia Commons.

To change the interpretation of the genetic code from three lettered words  to four, Chin and his colleagues had to make new ribosomes, and new tRNAs.  To create these new ribosomes, they designed orthogonal ribosomes, or o-ribosomes. O-ribosomes are genes inserted to produce extra ribosomes that operate in the cell alongside the regular ribosomes. The cell functions because it has the regular ribosomes to maintain its viability. The ribosomal RNA in the o-ribosomes is free to be mutated to create new unnatural traits: in this case, the ability to serve as a platform read four-letter codons. They selected for Escherichia coli bacterial cells that expressed a o-ribosomes which translated a four-letter codon in a gene, which would otherwise go untranslated by the regular ribosome. The gene gives the bacterial cells resistance to the antibiotic chloramphenicol. So cells that survive a dosage of chloramphenicol are those which have functioning o-ribosomes, as they have the chloramphenicol resistance gene that is being translated by the o-ribosomes.

They also needed to create new tRNAs that have an four-nucleotide anticodon (the part that complementarily binds to the messenger RNA –  see figure above.)  So the surviving E. coli cells have a population of working o-ribosomes, regular ribosomes, modified tRNA (with a  four-letter anticodon) and regular tRNA.

Then they took their work a step further. Each three-letter tRNA carries a specific amino-acid, depending on its anticodon. Thus tRNA_AAG will always have a phenylalanine attached, because CTT (the complement of AAG on the messenger RNA) codes for phenylalanine. If you start messing with that, the translation machinery will produce non-functional proteins, which will probably kill the cells pretty quick. But with the orthogonal 4-letter code machinery, that is not really a problem: the orthogonal machinery operates alongside the normal one. Also, there are no amino acids naturally assigned to any four letter code, because this code does not appear in nature in the first place! So Chin’s lab assigned an unnatural amino acids to a four-letter code. The non-naturally occurring p-azido-l-phenylalanine amino acid was assigned to tRNA_UCCU. They then showed that the whole alternative translational machinery worked by synthesizing a mutant of the protein calmodulin which used this amino-acid in its structure.

Why do it? Well, personally I don’t see the need for justification: just being able to do it is so cool!  But seriously: think of the ability to design proteins from up to 4⁴=256 different amino acids other than the 22 we have now.  The possibilities of tinkering with existing proteins using this orthogonal, four-letter based machinery are huge. The other benefit of this orthogonal synthesis setup is the ability to control this orthogonal translational machinery: because it does not use the three-letter vocabulary, this orthogonal machinery would be much easier to manipulate, tinker with and switch on and off without getting in the way of regular cellular translational machinery. The analogy to a car assembly line breaks here. It is as if two different models are being assembled on the same line just by using different robots. The better analogy is for a program source code to be read by two different compilers, each producing a different program. Awesome.

Seriously, this is what I first thought when I saw the cover of this week’s Nature, and the associated drawings  in the press.  The dude’s haircut seems like it was even bad in the ’80s… 2080 BCE that is, which is when his body is dated. Approximately.

Inuk, artist's impression

A large group of researchers were involved in analyzing DNA from a 4,000 year old man found in Greenland. There is an interesting story on how the sample was obtained. Eske Villerslev spent 2 months looking for human remains in archaeological sites in Greenland, to no avail. When complaining about it to a friend, he learned that that friend’s father had already given hair samples to the national museum of Denmark… back  in 1986. Serious slap on the forehead!

The preserved DNA was of great quality. Also, this is 2010: we have a plethora of genotypic data that lets us associate a genome with phenotypes, and geographical origin. Inuk, as he was dubbed, shares many traits with east Asians, and much less with contemporary North American Inuit or other Native Americans. This means that Inuk and his people migrated fairly recently to Greenland from Siberia and across North America. Inuk and his people, the (now extinct) Saqqaq have no relationship to contemporary Native Americans. This was also shown in an earlier study of the mitochondrial DNA.

What do we know about Inuk himself? He had blood type A+; thick black hair and very likely a receding hairline due to a baldness allele; brown eyes; shovel-graded front teeth (East  Asian characteristic); dry type earwax… before you laugh that is actually, another characteristic of Asian populations on the Siberian and Chinese east coast. He also had alleles associates with human adaptation to cold temperatures.

And a bad haircut; but great press nevertheless (just got to Google News and search for  “Greenland Genome” – see, for example, the NYTimes.)

This post has been Slashdotted. Exercise extreme caution.

Gilbert MT, Kivisild T, Grønnow B, Andersen PK, Metspalu E, Reidla M, Tamm E, Axelsson E, Götherström A, Campos PF, Rasmussen M, Metspalu M, Higham TF, Schwenninger JL, Nathan R, De Hoog CJ, Koch A, Møller LN, Andreasen C, Meldgaard M, Villems R, Bendixen C, & Willerslev E (2008). Paleo-Eskimo mtDNA genome reveals matrilineal discontinuity in Greenland. Science (New York, N.Y.), 320 (5884), 1787-9 PMID: 18511654

If the title of this post makes you cringe, then you belong to a minority of people who realize why the phrase “highly evolved” is so wrong. Unfortunately, “highly evolved” (as an absolute term) and “more evolved” (as a comparative term) seem  to be used all-too frequently.  They are uttered not only by non-scientists and non-biologists but even by scientists who should know better. Even when they catch themselves after blurting out “highly evolved” in a conversation (or, more embarrassingly, in a lecture), the damage is done. Yet another Freudian (Darwinian?) slip that tells of a fundamentally bad grasp on evolution. And, yes, I know, this topic has been written about by many of my betters, who are vastly more evolved better writers than I, with much better breadth and depth of knowledge of evolution, and a reach to a much wider audience.

More evolved? Source: Wikimedia commons, public domain.

So why am I writing about it? Well, this is my blog and ranting in it is my prerogative. And despite the Richard Dawkinses and Steven Jay Goulds of this world, the use of this phrase still persists. So it is up to us foot soldiers of the blogging community to do our own modest bit. If I prevent any of my six readers from being tempted to utter this phrase the next time it is (wrongly) deemed appropriate, then I have done my bit.

Why is this “highly evolved” used so much? And why is it wrong?

Consider the sponge, and then consider Albert Einstein. There are certain traits that Einstein had, that a sponge does not. We deem these traits to be of merit. Einstein developed a fundamental theory in physics. He  played the violin. He  ate with a knife and fork, had binocular color vision, opposable thumbs and he cultivated his facial hair in the form of a mustache.

A sponge… well, to be brief, does not have all those qualities we hold in such high merit. It kinda sits there at the bottom of the shallow ocean, flopping about, filter feeding, pooping and apparently not much else. Clearly, there are qualities to Einstein that make him more interesting than the sponge.

Less evolved? Source: Wikimedia Commons

Einstein seems, intuitively, to be more complex than a sponge, and that complexity can be quantified directly, in many ways. Actually, this is a pretty contentious point by itself: can we speak of organism complexity? Can we quantify the complexity of an organism and compare between different species? And what exactly would the complexity metric we choose tell us?

But let us assume, for argument’s sake, that our intuition that Einstein is more complex than a sponge is correct. For example, we can imagine a measure derived from the diversity and number of cells. Obviously there are more cell types in Einstein than in a sponge. Does that mean he is also more evolved? Are humans a more  evolved than sponges? Chimps? After all, did life not start 3.85 billion years ago as simple and over time became more complex? Progressing, as it were from simple unicellular bacteria through more complex sponges all the way to the crowning achievement of humans? Had humans not, in a sort of (alas, Pyrrhic) victory, mastered the Earth and competed with many of earth’s species to the latter’s extinction? Isn’t competition what evolution is all about? And isn’t human victory a direct result of human complexity making humans “more evolved”? So isn’t “complexity” an end product of evolution, the more complex you are the more successful you are, and the more evolved you are?

No, no, no, no, no, and no.

The reason for this series of compounding errors is the mistaken notion that evolution by natural selection is a progression resulting in a production of increasingly complex life.  Evolution is not goal oriented, and there is no teleology involved. The increasing complexity of organisms along time may seem to involve a  progressive process, but there is none. It is a “statistical illusion”.  What do I mean by that? Well, life did start out in less complex forms, that became more complex. But the less complex forms remained as well. Thus the distribution of complexity increased over time, but there is no directionality towards progress: the less complex life remained around as well. But over 3.85B years, complexity has had a chance to manifest itself in life, as natural selection favored some initial complexities, and those extended to become even more complex. Yes, we can trace a direct route from the first multicellular organisms, through sponges, invertebrates, vertebrates. But humans, chimps, sponges and bacteria living on Earth today are the result of exactly the same selective forces that have shaped life since  it crawled out of an underwater volcano, or wherever. Complexity emerged over time, and is still emerging. But complex organisms are being added to the pool of life, rather than replacing the simple organisms. The result is an increase of a distribution of complexity levels, not the moving of an entire curve of complexity rightwards.

Apparent progress due to a to a 'wall' restricting where random change can take things. Adapted from SJ Gould. Reproduced under CC from talkorigins.org

The point I am trying to make is that humans may be more complex than sponges, but we are not “more evolved” nor are we “highly evolved”.  There is no progressive process, and all of life on earth is the result of the same 3.85B years of selective pressures.

For a really good historical overview of teleological, or purpose-driven, thought in evolution, look to talkorigins.org.

Few know that Einstein was teaching evolution at Princeton. Physics was just a cover.

All of this does not mean that Highly Evolved by The Vines is not a kick-ass song. Listening to it is also  a good way to get the rage from hearing “highly evolved” out of your system.  Note the low complexity of the video:

In celebration of the biohackathon happening now in Tokyo, I am putting up a script that is oddly missing from many bioinformatic packages: extracting intergenic regions. This one was written together with my student, Ian. As for the biohackathon itself, I’m not there, but I am following the tweets and  Brad Chapman’s excellent posts:

• Day 1
• Day 2
• Day 3
• Day 4

About intergenic regions: intergenic regions are as interesting and sometimes even more interesting than the genes themselves: when you are interested in promoters, transcription factor binding sites or almost any other transcription regulation mechanism. Here’s a simple script to find intergenic regions. It reads a genbank formatted file and uses the information there to extract the intergenic regions. The sequences are written to a FASTA file.

#!/usr/bin/env python
import sys
import Bio
from Bio import SeqIO, SeqFeature
from Bio.SeqRecord import SeqRecord
import os

# Copyright(C) 2009 Iddo Friedberg & Ian MC Fleming
# Released under Biopython license. http://www.biopython.org/DIST/LICENSE
# Do not remove this comment
def get_interregions(genbank_path,intergene_length=1):
    seq_record = SeqIO.parse(open(genbank_path), "genbank").next()
    cds_list_plus = []
    cds_list_minus = []
    intergenic_records = []
    # Loop over the genome file, get the CDS features on each of the strands
    for feature in seq_record.features:
        if feature.type == 'CDS':
            mystart = feature.location._start.position
            myend = feature.location._end.position
            if feature.strand == -1:
                cds_list_minus.append((mystart,myend))
            elif feature.strand == 1:
                cds_list_plus.append((mystart,myend))
            else:
                sys.stderr.write("No strand indicated %d-%d. Assuming +\n" %
                                  (mystart, myend))
                cds_list_plus.append((mystart,myend,1))

    for i,pospair in enumerate(cds_list_plus[1:]):
        # Compare current start position to previous end position
        last_end = cds_list_plus[i][1]
        this_start = pospair[0]
        strand = pospair[2]
        if this_start - last_end >= intergene_length:
            intergene_seq = seq_record.seq[last_end:this_start]
            strand_string = "+"
            intergenic_records.append(
                  SeqRecord(intergene_seq,id="%s-ign-%d" % (seq_record.name,i),
                  description="%s %d-%d %s" % (seq_record.name, last_end+1,
                                                        this_start,strand_string)))
    for i,pospair in enumerate(cds_list_minus[1:]):
        last_end = cds_list_minus[i][1]
        this_start = pospair[0]
        strand = pospair[2]
        if this_start - last_end >= intergene_length:
            intergene_seq = seq_record.seq[last_end:this_start]
            strand_string = "-"
            intergenic_records.append(
                  SeqRecord(intergene_seq,id="%s-ign-%d" % (seq_record.name,i),
                  description="%s %d-%d %s" % (seq_record.name, last_end+1,
                                                        this_start,strand_string)))
    outpath = os.path.splitext(os.path.basename(genbank_path))[0] + "_ign.fasta"
    SeqIO.write(intergenic_records, open(outpath,"w"), "fasta")

if __name__ == '__main__':
    if len(sys.argv) == 2:
         get_interregions(sys.argv[1])
    elif len(sys.argv) == 3:
         get_interregions(sys.argv[1],int(sys.argv[2]))
    else:
         print "Usage: get_intergenic.py gb_file [intergenic_length]"
         sys.exit(0)

What are we seeing here?

Lines 11-16 are the preamble: we read the GenBank file using Biopython’s genbank parser in line 12.  Beacuse we expect a genome file, which contains a single record, this is a one-time read. Note that this is a rate limiting step, and can take a couple of seconds. Took me ~2secs to read the full E. coli genome on my Linux box.  We prepare one list for the + strand intergenic regions (13), another one for the minus strand intergenic regions (14) and one for all the records (line 15).

The rest of the code are three loop blocks: lines 16-28 I loop over the genbank features, extracting the coordinated of the genes themselves. Line 32-41 I find the intergenic regions on the + strand. Lines 42-52 I do the same for the “-” strand.

Now for a philosophical interlude: although there is a way to read all the intergenic regions in a single pass, I subscribe to the “code simple” doctrine of research software writing. Code performance optimization is a low priority for me. I’d much rather have something that is simple to write,read and modify. I also don’t want to spend too much time coding and elegant script for elegance’s sake, especially if I may not use it too much. Historically, scientific code written for research is mostly extinct: thrown away after a short lived hypothesis was tested and ended its days. Research coding is mostly throwaway glue code. Very rarely it matures into a product. Then, and only then, can you apply all those fine software engineering you learned in college. Before that, write fast and simple.

But I digress. Line 17 loops over the features in the genome file. Line 18 we identify if it is a coding sequence (CDS). If so, we identify the start position, and position and the strand the CDS is on. The list cds_list_minus is a list of 2-tuples. Each 2-tuple is the start and end positions of a CDS on the minus strand. (If you would like to go over the genes, as opposed to coding sequences, change line 18 to:

if feature.type == 'gene':

(or better yet, pass an argument that defines it.)

cds_list_plus, is, yes, the same as cds_list_minus, only for the plus strand (line 24).

Sometime, a CDS does not contain information on which strand it is. With genome files, that is usually the case with single stranded viral genomes. Therefore, we put in the default assumption that if there is no strand indication, then the feature is is on the plus strand. We generate a warning message nevertheless (lines 25-28).

Lines 30-41 we loop over the plus  strand list, and identify the coordinates between the genes. Python’s enumerate function is very useful here. The enumerate function allows us to iterate over a list, but at the same time keep track of which index we are in when looping over the list. So in line 30, pospair receives the start and end coordinates of a CDS as a 2-tuple, while i receives the actual number if the index in the plus strand CDS list. In that way, we can look back to the previous list member, find the coordinates where that CDS ends, and where the current CDS begins. The two coordinates make up the beginning and end of the intergenic regions between those two genes on that strand. In line 35 we check if the intergenic region length is equal to or larger than a threshold: suppose we are only interested in those intergenic regions that are longer than 100 bases? (The default value is 1, see line 11.) In lines 38-39 we build a biopython sequence object that contains an informative header, and the sequence of the intergenic region. The description which goes in the sequence header contains the start and end coordinates of the intergenic region, and the locus ID of the CDS directly downstream from it. The sequence object is appended to a list, which will eventually get written (lines 40-41).

Lines 42-52 are a repeat of lines 30-41, only for the minus strand.  Lines 53 & 54: the list that contains all the intergenic region sequence objects gets written to its own fasta file.

Finally, line 56-63 are boilerplate code, that make this script runnable from the command line. Have fun looking at intergenic regions. Let me know of you find something interesting.

Marketing yourself is a process you go through many times. The job hunt comes to mind — but not only. Academia is rife with self-marketing: grant applications, promotion & tenure reports, attracting students to your courses and to your lab,  competing for conference lecture slots, giving a lecture.

But not only academia, and not only in the present day.

Leonardo di ser Piero da Vinci was, among many other things, a civil and military engineer.  Marc Cenedella has this report on Da Vinci’s resume, sent to the Duke of Milan, who apparently was in need of some military hardware.  The resume, such as it is, is truly a great piece of self-marketing. Note how LDV tailors his resume to the Duke’s needs. He does not list his artistic achievements (which were many by the time), but only those achievements and skills that fit his prospective employer’s interests. My observations are in boldface.

“Most Illustrious Lord, Having now sufficiently considered the specimens of all those who proclaim themselves skilled contrivers of instruments of war, and that the invention and operation of the said instruments are nothing different from those in common use: I shall endeavor, without prejudice to any one else, to explain myself to your Excellency, showing your Lordship my secret, and then offering them to your best pleasure and approbation to work with effect at opportune moments on all those things which, in part, shall be briefly noted below.

1. I have a sort of extremely light and strong bridges, adapted to be most easily carried, and with them you may pursue, and at any time flee from the enemy; and others, secure and indestructible by fire and battle, easy and convenient to lift and place. Also methods of burning and destroying those of the enemy. [Before the legendary British WWII Bailey Bridge]

2. I know how, when a place is besieged, to take the water out of the trenches, and make endless variety of bridges, and covered ways and ladders, and other machines pertaining to such expeditions.

3. If, by reason of the height of the banks, or the strength of the place and its position, it is impossible, when besieging a place, to avail oneself of the plan of bombardment, I have methods for destroying every rock or other fortress, even if it were founded on a rock, etc.

4. Again, I have kinds of mortars; most convenient and easy to carry; and with these I can fling small stones almost resembling a storm; and with the smoke of these cause great terror to the enemy, to his great detriment and confusion. [Battlefield smoke].

5. And if the fight should be at sea I have kinds of many machines most efficient for offense and defense; and vessels which will resist the attack of the largest guns and powder and fumes.

6. I have means by secret and tortuous mines and ways, made without noise, to reach a designated spot, even if it were needed to pass under a trench or a river.

7. I will make covered chariots, safe and unattackable, which, entering among the enemy with their artillery, there is no body of men so great but they would break them. And behind these, infantry could follow quite unhurt and without any hindrance. [Yes, LDV invented the tank! Note also the combined infantry / armor tactics].

8. In case of need I will make big guns, mortars, and light ordnance of fine and useful forms, out of the common type. [Not only can I do it, I can do it cheaply, by re-purposing your existing ordinance.]

9. Where the operation of bombardment might fail, I would contrive catapults, mangonels, trabocchi, and other machines of marvelous efficacy and not in common use. And in short, according to the variety of cases, I can contrive various and endless means of offense and defense.

10. In times of peace I believe I can give perfect satisfaction and to the equal of any other in architecture and the composition of buildings public and private; and in guiding water from one place to another. [Dear Duke: you want to hire me even if you are not fighting, or you will want to keep me after your wars are over.]

11. I can carry out sculpture in marble, bronze, or clay, and also I can do in painting whatever may be done, as well as any other, be he who he may. [Another peacetime skill.]

Again, the bronze horse may be taken in hand, which is to be to the immortal glory and eternal honor of the prince your father of happy memory, and of the illustrious house of Sforza. [Catering to the employer's vanity. Gotta know how to do it right...]

And if any of the above-named things seem to anyone to be impossible or not feasible, I am most ready to make the experiment in your park, or in whatever place may please your Excellency – to whom I comment myself with the utmost humility, etc.” [I realize make big claims, but I can back them up. Just get me an interview.]

edw513 at Ycombinator.com has adapted this resume to fit current market needs:

If it worked for Leonardo da Vinci, maybe it could work for me. The next time I’m looking for a job, I’ll try this:“Most Illustrious Proprietor, Having now sufficiently considered the specimens of all those who proclaim themselves skilled developers of applications of business, and that the invention and operation of the said programs are nothing different from those in common use: I shall endeavor, without prejudice to any one else, to explain myself to your Company, showing your Management my secret, and then offering them to your best pleasure and approbation to work with effect at opportune moments on all those things which, in part, shall be briefly noted below.

1. I have a sort of extremely light and strong functions and modules, adapted to be most easily ftp’d, and with them you may pursue, and at any time combine them with others, secure and indestructible by standard mean time to failure of hardware and denial of service, easy and convenient to compile and catalog. Also methods of unzipping and storing the data of the customers.

2. I know how, when a website is besieged, to shard data onto the cloud, and make endless variety of mirrors, and fault tolerant disks and RAIDs, and other machines pertaining to such concerns.

3. If, by reason of the volume of the data, or the structure of the btrees and its indexes, it is impossible, when conducting a search, to avail oneself of sub-second response time, I have methods for benchmarking every process or other function, even if it were interpreted, etc.

4. Again, I have kinds of functions; most convenient and easy to ftp; and with these I can spawn lots of data almost resembling a torrent; and with the download of these cause great terror to the competitor, to his great detriment and confusion.

5. And if the processing should be on the desktop I have apps of many machines most efficient for data entry and reporting; and utilities which will satisfy the needs of the most demanding customers and users and consumers.

6. I have means by secret and tortuous scripts and modules, made without leaving tracks, to generate source code, even if it were needed to run on a client or a server.

7. I will make secure firewalls, safe and unattackable, which, entering among the hackers with their utilities, there is no body of crackers so great but they would break them. And behind these, software could run quite unhurt and without any hindrance.

8. In case of need I will make big properties, methods, and collections and useful forms, out of the common type.

9. Where the operation of compiling might fail, I would contrive scripts, functions, routines, and other parameter driven processes of marvellous efficacy and not in common use. And in short, according to the variety of cases, I can contrive various and endless means of data entry, reporting, and storage.

10. In times of low revenue I believe I can give perfect satisfaction and to the equal of any other in maintenance and the refactoring of code public and private; and in guiding data from one warehouse to another.

11. I can carry out code in Javascript, PHP, or C, and also I can do in network administration whatever may be done, as well as any other, be he who he may.

Again, the intranet app may be taken in hand, which is to be to the immortal glory and eternal honor of all your customers of happy memory, and of the illustrious house of Google.

And if any of the above-named things seem to anyone to be impossible or not feasible, I am most ready to make the experiment in your data center, or in whatever place may please your Businessperson – to whom I comment myself with the utmost humility, etc.”

Boys and girls, it can be done. Published in the Journal of Irreproducible Results (Where else?)