Tasty, tasty science 2007

As you may have read here before, I like me some science when I'm commuting or doing dishes - the two main times I put on my iPod and listen to podcasts.

Scientific American continues to deliver the best stuff, both in their short 60-Second Science daily series and in the longer Science Talk episodes.

Now you science-phobes stick with me here. The more you know about how living creatures reproduce the more entrancing the world becomes.

My favorite episode of the ones I've been catching up with has a great piece with University of Wisconsin evolutionary biologist Sean Carroll on the role of gene duplication in evolution. Totally cool stuff.

First, some background: all living creatures have molecules of DNA in their cells. DNA carries genetic information which controls the traits of the living creature. To quote Wikipedia, a gene is a hereditary unit consisting of DNA that occupies a spot on a chromosome and determines a characteristic in an organism. Genes are passed from parent to child in sexual species through the combination of genetic material from each parent. This process is called meiosis (pronounced my-oh-sis).

You've probably seen a diagram of DNA which looks like a long zipper. What happens in meiosis (in simplistic terms) is that each of the parent zippers gets unzipped and zips back together with the other half of the other zipper, so you get the mother's and father's DNA getting hooked together. What happens in this process is genetic recombination and that is an opportunity for change since the parents' DNA will not be identical. In other words, meiosis and sexual reproduction produce genetic variation.

What that means is that the living creature could have traits or behaviors which are different from its parents and/or from the offspring of other creatures of the same kind.

And what that means is that it might have a better chance of surviving (or at least breeding) in its particular environment. If so, it becomes more likely than those other creatures to pass its genetic material on to its own offspring. Multiply this by hundreds or thousands of generations and you've got survival of the "fittest".  By "fittest" I mean the most able to survive (or at least breed) in a particular environment. It's not "best" - there's no goal or ideal here; it's just what currently, under these conditions works.

As you can imagine, migration of a creature into a new area can introduce new genetic variation in the population - the gene pool, if you will - of that area.

The last but certainly not least factor in genetic variation is mutation. Again to quote Wikipedia, mutations can be caused by copying errors in the genetic material during cell division [including meiosis!], by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can occur deliberately under cellular control during processes such as hypermutation. The resulting changes can be small or large - even as large as complete duplication of a gene - and may or may not have any effect on the creature's traits or behaviors.

If a mutation makes a creature less successful at surviving and/or breeding, it's less likely to pass on its genetic material to future generations. If the mutation is beneficial - i.e. improves the chances of survival and/or breeding - the genetic change is more likely to be passed to another generation. Note that a mutation doesn't need to otherwise benefit the creature to be beneficial to the continuation of that genetic pattern; it's all about reproduction.

The overwhelming majority of mutations are neutral; they have neither effect and may even be repaired by the cell. In many cases, though, these genetic changes are simply passed on through the generations doing neither harm nor good to the genetic "fitness" of that creature.

Which brings us back to this cool podcast.

when gene duplication was first noticed and realized to be important, most researchers thought that what it did was give you one copy of the gene that could continue performing its original important function, and another copy that natural selection could then experiment with to find a new function. But in your paper you talk about the fact that it might be the case that both genes wander off to find new functions.

Rather than my summarizing it, go give it a listen or read the transcript. It's totally cool and really well explained. Genetics are so neat!

(And if you want to learn more about molecular biology, I recommend Dr. Zach's Evolution 101 podcast. Pause the playback of the current episode (grrr) and scroll down to episode 108 "Molecular Biology Primer". Good stuff, which, because of when I first listened to it, I now probably irrevocably associate with doing a jigsaw puzzle in the Egyptian House in Penzance, Cornwall.)

Mmm, science and skepticism. 2007

I've got some good podcasts episodes from my many subscriptions for you today.

I've really been enjoying Point of Inquiry. Check out these two interviews:
Garrett G. Fagan - loads of fun hearing this author of Archaeological Fantasies: How Pseudo-archaeology Misrepresents the Past and Misleads the Public rip apart a whole bunch of false science about the past. This one is worth it for the incredibly long litany of proposed locations of Atlantis alone.

Peter H. Gilmore - this was a very surprising one. Turns out the Satanists don't believe in Satan as a god. Also, they call themselves a religion without believing in the supernatural at all. And their high priest turns out to be quite charming in interviews. I'm not drawn toward their church, but this interview cleared up lots of assumptions I'd made.

From the Science & the City podcast, this session with Oliver Sacks reminiscing fondly about his favorite parts of the table of chemical elements is just plain sweet.

A more recent session from this one was Alan Walker on the Search for "the Missing Link". Yum! Physical anthropology!

60-Second Science continues to be reliably rewarding. Check out this simple little news story about what does and doesn't work in health education: Abstintence-Only Programs Fail.

I've unsubscribed to a couple podcasts that I mentioned before, Science Update Podcast weekly edition (too fluffy) and This Week In Science (too much like annoying morning talk radio shows like Sarah & No Name on Alice), and subscribed to a new one, The Skeptics Guide To The Universe.

"Where you decide to put your time and attention says a lot about who you are." 2007

That's what Merlin Mann said in a great recent lecture at Google which he's kindly made available as part of his Inbox Zero series of posts.

So I was thinking about that, as well as the good practical email management advice from his talk, and I realized that one thing I really care about is science. But I have not been investing a proportional amount of my time into science compared to my interest in it.

I thought "Where do I have room in my day to fit in some science without pushing out something else that also matters to me or which I choose to make important in order to pay my bills and have some sort of career?"

Hello, commute!

And hello again, cute pink 4gb iPod which was a present from my friends Edmond & Shannon a few years back when they shared my place while escrow on their place cleared. I'd been neglecting it and only remembering about it when I was on the bus next to some incredibly banal and annoying conversation - usually one side of a cellphone conversation at that.

I'm now subscribing to a whopping 10 new podcasts in addition to the lovely 60-Second Science which I had already been enjoying on my laptop. And boy do I listen to them! Somehow even though my brain is sick of email and articles by the end of the workday (or in anticipation of it), listening to even fairly complex discourse is thoroughly enjoyable.

I've signed up for
- NOVA scienceNOW
- Ockham's Razor (the August 5th piece on Abolishing Weapons of Terror was very good)
- Point of Inquiry
- Science @ NASA Feature Stories
- Science & the City (from which I particularly enjoyed last Friday's episode with Alan Walker on The Search for "The Missing Link", a really top-notch ramble through physical anthropology. Highly recommended!)
- Science Friday
- Science Talk: The Podcast of Scientific American (and now I will out myself as a new huge admirer of Steve Mirsky's writing/delivery, both when he's seriously sharing knowledge and when he's barely restraining his sarcasm on, for example, people who play the lottery & their understanding of probability </fangirl>)
- Science Times
- Science Update Podcast weekly edition
and
- This Week In Science

You can get all these, as well as Merlin Manns 43 Folders podcast and They Might Be Giants podcast (my other subscriptions) most easily through iTunes, but you can also download them from some website somewhere, no doubt. Google is your friend in need for that.

What do you love? Go fit a little more of it into your otherwise idle moments and get reconnected.

And if you love science too, and have recommendations for more good podcasts, please share them in the comments.

Yum! Science!

Feeling better about my knees all the time 1999

As a defense against predators, the unassuming ladybug can squirt a foul-smelling, bitter-tasting yellow liquid out of its knee joints.
- Birds & Blooms magazine
(another fine link from Uncle Larry)