An introduction to DNA

I decided to take the biology stuff ‘from the top‘ and this is as far as I’ll go today:

…This is pure gold. I’m currenty at chapter 9 in Russell’s Genetics…, which is about ‘The Organization of DNA in Chromosomes’, after having read the chapter about ‘The Structure of Genetic Material’ (‘the chemical composition of DNA and RNA’). So I can tell you that Sal’s treatment is, as he also mentions himself again and again, grossly simplified – some of this is very complex stuff. However ‘the basics’ needn’t be that hard to get, and Salman Khan does his best to make this stuff approachable, even to people with very little knowledge of biology.

Today’s been a great day where I feel like I’ve learned a lot. If you’ve liked (some of..?) the videos I’ve posted from Khan Academy so far, then you really should go make a user profile (one can log in via google or facebook) and start exploring more systematically. There’s a lot of good stuff here.


July 12, 2011 Posted by | Biology, Genetics, Khan Academy, Lectures | 10 Comments

Once again, there is no soul (‘outside the brain’)

“The idea that the self, or the conscious mind, emerges from the workings of the physical structures of the brain – with no need to invoke any supernatural spirit, essence or soul – is so fundamental to modern neuroscience that it almost goes unmentioned. It is the tacitly assumed starting point for discussions between neuroscientists, justified by the fact that all the data in neuroscience are consistent with it being true. Yet it is not an idea that the vast majority of the population is at all comfortable with or remotely convinced by. Its implications are profound and deeply unsettling, prompting us to question every aspect of our most deeply held beliefs and intuitions.

This idea has crept along with little fanfare – it did not emerge all at once like the theory of evolution by natural selection. There was no sudden revolution, no body of evidence proffered in a single moment that overturned the prevailing dogma. While the Creator was toppled with a single, momentous push, the Soul has been slowly chipped away at over a hundred years or more, with most people blissfully unaware of the ongoing assault. But its demolition has been no less complete.

If you are among those who is skeptical of this claim or who feels, as many do, that there must be something more than just the workings of the brain to explain the complexities of the human mind and the qualities of subjective experience (especially your own), then first ask yourself: what kind of evidence would it take to convince you that the function of the brain is sufficient to explain the emergence of the mind?

Imagine you came across a robot that performed all the functions a human can perform – that reported a subjective experience apparently as rich as yours. If you were able to observe that the activity of certain circuits was associated with the robot’s report of subjective experience, if you could drive that experience by activating particular circuits, if you could alter it by modifying the structure or function of different circuits, would there be any doubt that the experience arose from the activity of the circuits? Would there be anything left to explain?

The counter-argument to this thought experiment is that it would never be possible to create a robot that has human-like subjective experience (because robots don’t have souls). Well, all those kinds of experiments have, of course, been done on human beings, tens of thousands of times. […]

When people argue that activity of some brain circuit is not identical to a subjective experience or sufficient to explain it, they are missing a crucial point – it is that activity in the context of the activity of the entire rest of the nervous system that generates the quality of the subjective experience at any moment. And those who dismiss this whole approach as scientific reductionism ad absurdum, claiming that the richness of human experience could not be explained merely by the activity of the brain should consider that there is nothing “mere” about it – with hundreds of billions of neurons making trillions of connections, the complexity of the human brain is almost incomprehensible to the human mind. (“If the brain were so simple that we could understand it, then we would be so simple that we couldn’t”).”

Read all of it here.

July 12, 2011 Posted by | Biology, Random stuff | Leave a comment

Krebs / Citric Acid Cycle (yep, Khanacademy’s still awesome!)

Lots more here. I also took a personal interest in this short but neat and instructive video:

He also has a couple of follow-ups to that one here, here and here. They are also quite neat; a lot of learning in a short amount of time.

Btw, I just went and made myself an account to Khanacademy. I consider it quite likely that I’ll visit the site more frequently in the future than I used to do. If I do I’ll do my best to remember to post on my progress here as well.

The site has a lot of data on your progress and I like that kind of stuff. For instance now I know that I’ve spent 50 minutes today on the site (maybe information like that could potentially cause me to cut down on my time consumption of a good like this, but I actually don’t think that is in any way the most likely outcome..).

July 12, 2011 Posted by | Biology, Diabetes, Khan Academy, Medicine | Leave a comment