Well, it didn't LEAVE, but it did become far less common after 1500. Why? Was it leprosy? Or was it us? Or was is something else? I'm at SciAm blogs today talking about a brand new study on the genetics of leprosy bacteria. Head over and check it out!
Archive for the 'Evolution' category
Sings: *but that's why birds do it, bees do it, little fishies in the seeeeeas do it, let's do it...*
Let's come together. Into groups, schools, herds, flocks. Prey animals all over the world do it.
We know why prey animals tend to clump together. More animals means more eyes to spot predators. More animals means if the predator gets someone, it's less likely to be you. More animals means that the predator could get confused by so many bodies and miss entirely.
Those are the general reasons why prey animals hang together. But when they do hang together, such as when fish school, they also tend to MOVE together. It's not just a group of fish milling around, the fish group into clumps and move in coordinated patterns. Since so many species do it, we assume this has an evolutionary advantage, but we had no direct proof of this.
Until the authors of this paper decided to frustrate the heck out of some bluegill sunfish.
C. C. Ioannou, V. Guttal, I. D. Couzin. "Predatory Fish Select for Coordinated Collective Motion in Virtual Prey" Science, 2012.
...but it's not quite simple. 🙂
I'm at Scientific American blogs today discussing a recent paper recording mouse songs, and using them to find kinship patterns among mice. You can even listen to the mice sing to the their ladies! CUTE! Head over and check it out.
Today I'm at SciAm. I am NOT in fact talking about Paleolithic diets. What I AM talking about is tuna. Fished by people 42,000 years ago! I'll go over the evidence and why it might be surprising (hint, no fish hooks). Go over and check it out!
Well, at least, the only thing THESE birds have to fear is fear itself.
This is one of those studies that, when you lay it out, seems really...simple. Clear layout. Clear results. But it challenges a lot of the things that we once assumed about predator:prey relationships. Most particularly, it overturns the idea that the only thing making prey die from predation is the predators themselves.
This seems really simple, right? Fox eats bunny, lots of foxes mean the bunny population declines. Just foxes being AROUND bunnies (but eating, say, SmartOnes meals or something), well the bunnies wouldn't get eaten and the prey population would stay the same or even increase. Right?
Well...wrong. It turns out that sometimes what the prey population has to fear, is FEAR of predation itself.
Zanette et al. "Perceived Predation Risk Reduces the Number of Offspring Songbirds Produce per Year" Science, 2011.
(this is a full video by the authors, showing the results of their finding! Wish more people could do this!)
When it comes to mating, most species of animals have one sex that does all the work. Stereotypically, we think of the male putting in most of the effort, whether it's with extreme ornamentation like peacocks or with extreme effort like dung beetles. But it's not always the case, and sometimes females take the initiative. But in most cases the solicitor for sex doesn't really vary, it's the male, or the female, but not generally both.
Enter the butterfly: Bicyclus anynama. It's an African species often called the "Squinting Brown Bush Butterfly". I imagine that the genus "bicyclus" refers to the dual life cycle of the genus (though I couldn't find any solid information on that, anyone?), but to me it just makes me think of a butterfly riding a bicycle.
Sci usually blogs about things related to health, being a biomedical scientist as she is. But this, this is AWESOME. COMPLETELY AWESOME.
It's people. Tossing snakes. From towers.
And it made me think so forcibly of the Snake Fight Portion of One's Thesis Defense (which is brilliant and should be required reading for every grad and post-doc) that I HAD to blog it!
(Is this the same lab?)
Having heard about this book almost from the very beginning, I was of course totes excited to finally get a copy of it in the mail!! I dug in, and just now finally closed it, with the sigh of satisfaction I usually give when I complete a good history or a good story.
And in a way, Brian Switek's first book "Written in Stone: Evolution, the Fossil Record, and our Place in Nature" is both a good history, and a really great story (but unlike my usual fun stories, it contains no references to magic, pumpkin juice, or really awesome mystical swords). This book tells the story both of the evolution of life on earth, and the evolution of how we know what we know about life on earth today. Each chapter focuses on a specific type of animal living in our current environment (such as tetrapods, birds, mammals, whales, horses, elephants, and finally humans), and goes through, not only our current perception of how evolution eventually produced what we know of as the horse, the whale, or the mammoth, but ALSO how our understanding evolved. How scientists found the bones that led them to new ways of thinking about evolution. Where they worked, what they did, the arguments they had, the mistakes they made. This book is far more than a history of evolution. It's the story of how that history came about.
(From Laelap's blog at Wired)
I've of course been enjoying Brian's writing (at the blog Laelaps) for years now. I mean, who DOESN'T love dinosaurs? And WHALES? And MAMMOTHS (I have a particular fondness for mammoths). This book feels partly like a culmination of the past few years, and partly like a beginning. A culmination, because it follows from many of his blog posts, and a beginning, because with a book this good, there must be others.
Yup, the book was great. There is nothing dry about these bone stories, and Brian leads the reader along beautifully. Every time as I got to a point in a chapter where I thought "but what about...?" or "but why do...?", all I had to do was keep reading, the answer was right there. I ended each chapter amazed at how many new things I had learned, and ended the book with even more respect for evolution and all of its nuances than I had before. The many scientists featured for their discoveries come alive in their bickerings with each other. The confusion and concerns of where each research area was going appear just as immediate. Brian has not only portrayed evolutionary science, he has portrayed a lot of scientific life as well. With his final chapter on human evolution, Brian brought home not only how branching our family tree once was (it's more than a little spooky to realize we're the last branch of what used to be a very bushy tree of hominids), but how special we are, not in spite of our many branches and nuanced evolutionary history, but because of it.
So don't forget to check it out. The release date was yesterday, but things have been delayed, and the book should hit between Nov 15th and 22nd. It will make great reading for the science lover and fossil-fiend!!
PS: Only one minor quibble: MOAR PICTURES!!! Brian gave wonderful descriptions of all these creatures, some of which seem so fantastic they came out of Avatar. While there are many pictures, I think even more wouldn't hurt!
So we are now headed off to a new, shiny server which will hopefully make us all happy and responsive again! And what better way to start it off than with a paper that BLOWS MY MIND?!?!
I'll admit that Ed actually blogged it before me (though I had intended to blog it for a while), and so at first I thought I'd leave it alone, but then Ed and Razib put on the peer pressure to have me blog it, too. I'm a doormat for those guys. 🙂
But really, it's a great paper to blog. When I first looked at it, I thought "oh, maybe it's your basic viral gene transfer and they got it looking all nice". But when I saw the specific results...my mind was blown that much more.
So here we go, let's talk about some antibiotic resistant bacteria.
So far, it's been about three months since Sci's dissertation. During that time, she has:
- defended her dissertation
- moved to New Huge City
- started a post-doc(!)
- been sending out paper to beef up her little CV
- been learning large numbers of new, difficult, cool techniques
- been awesome
- completely failed to take a vacation.
Sci has ALSO, during this time, accrued yet another tidy little pile of books for review. In fact, there was a tidy little pile waiting on the doorstep of her new apartment ON THE DAY SHE MOVED IN. Sci was simultaneously excited (presents!) and dismayed (AUGH MORE SCIENCE TO READ) by the gifts. And so it has taken her a little bit of time to get started. I did get through "your brain on food", but other than that it's been slow going. And Sci admits that she paused a bit for some fiction on the way (delicious, delicious fantasy fiction. OM NOM NOM), and may pause for a bit more before she keeps going.
Anyway, the latest one the arrive in the mail was Supernatural Selection, by Matt J Rossano. And though it took me a while, due to various factors, Sci's through it. And here is her review.
Supernatural Selection, by Matt J. Rossano