Friday, October 28, 2011

do dooo, do do dooo, do do DOOO, do do do doooo

You know it- the eloquent scene at the end of Jurassic Park where the exhausted and soiled (but just enough to make him even MORE sexy) Dr. Grant stares out the window at the sea birds flying alongside the rescue helicopter. Do dooo, do do dooo, do do DOOO, do do do doooo…

Most movies’ final scenes are tributes to the profound emotional change the main character experiences. But not Jurassic Park. Sure, Dr. Grant likes kids now. Whatever. The final images of Jurassic Park acknowledge the taxonomic link between dinosaurs and birds- one of the most important connections made in modern day zoology.

The tricky thing about taxonomy that deals with long-gone species is that, well, they’re dead. We can use fossils to look at what bones they had, where they were, what shape they were, what other bones they were touching. Then we make our best guesses at what muscles and other soft tissues were connected where. Then, we make another best guess at what evolutionary path these structures took through time. It’s a game of logic and guessing. But one little critter helped to make the dino-bird connection less of a guess.

Archaeopteryx. “Archaeo” meaning ancient, “pteryx” meaning wing. “Old winged one”, you might call it. The fossil dates back to the late Jurassic Period (notable for crowd favorites like the long-necked Diplodicus, bipedal predators like Allosaurus, and the spiky-tailed Stegosaurus). Now take a good, hard look at old winged one, pictured below. What do you see?






We’ve got a long frazzlin’ little neck happening. And a long tail- deducible from the numerous caudal vertebrae. Long legs with a funky, kind of extended ankle joint. How do you think this thing stood? Probably upright. That tail seems like it would balance the animal as it stood bipedally on its long foldable legs. Check out those arms. Do they end in hands? Not really, they end in long creepy fingers. Though you can’t tell from the picture, it’s about the size of a grackle. But we still haven’t mentioned the most important feature.

Feathers. There are clear, unmistakable, beautiful impressions of feathers surrounding the animal. Those are undoubtedly wings with obvious, perfectly structured flight feathers. Caudal (tail) feathers are also present. We have a flying, feathered reptile here, folks. A bird. What many argue is the first bird.

The presence of feathers is one of the defining characteristics of modern-day birds, and feathers’ dino-origins are so fascinating that a whole new post is necessary to do them justice (keep your eye out, it’ll be a good one).  The finding of the feathered Archaeopteryx fossil turned the field of taxonomic zoology on its head. Here we have an unmistakable transition fossil that shows us a freeze-frame of group of dinosaurs becoming modern-day birds. The predatory raptors like Velociraptor reduced in size (which would later make flight manageable). They sprouted feathers, which decorated their arms. As these feathered mini-raptors fled predators, it became advantageous for those with feathers that provided a little lift to evade being eaten. So, flight was selected for and boom. We have small, flying, feathered dinosaurs. We have birds.

One more time. Sing it with me, people. Do dooo, do do dooo, do do DOOO, do do do doooo…


Although this phylogenetic hypothesis is generally accepted in the scientific community, there is debate. For further investigation:

A reconsideration of the reptilian relationships of Archaeopteryx. Tarsitano, Samuel. Max K. Hech. Zoological Journal of the Linnean Society. Volume 69, Issue 2, pages 149–182, June 1980

Evidence from Claw Geometry Indicating Arboreal Habits of Archaeopteryx. Feduccia A. Science 5 February 1993. Vol. 259 no. 5096 pp. 790-793.

Feathers of Archaeopteryx: Asymmetric Vanes Indicate Aerodynamic Function Science. Feduccia A. 9 March 1979. Vol. 203 no. 4384 pp. 1021-1022.

Monday, October 24, 2011

can’t we all just get along?

Evolution- my area of special study in college- is a fascinating topic. For it’s scientific implications, mainly. But also for its social implications. Since I will be writing a hefty amount about evolutionary processes, I think it is a good idea to be upfront about how I feel about it.

I used to avoid telling people that I majored in evolution. Not because I was embarrassed, but because I immediately became a Godless a-hole to people whom otherwise previously really seemed to like me. And to be honest, I to this day don’t really tell people whom I suspect will disown me. It’s silly, I know. But I like friends! What can I say.

In my Evolution and Systematics class at Auburn, my professor Dr. Armbruster devoted two whole lectures to talking about the societal aspect of evolutionary theory. Any way you slice it, it’s an important pivot point between science and people. And as with any hot button issue, there are the extremes. There are those who want to use evolutionary theory to disprove the existence of God. There are those who believe the existence to God disproves evolution. And then there is the majority- reasonable folks that fall somewhere in the middle.

The fact of the matter is, God cannot be disproved. So to all of the faithful- let me reassure you that science is mute on religion. No amount of research hours, expensive machinery, departmental funding, or clever experimental set-ups can prove or disprove God. Sleep well knowing that science will never be able to touch faith. MC Hammer style.

That being said, there is as much evidence for evolution as there is for gravity. On this blog, I will write of evolution as a scientific fact. Because that’s what it is. It happened. It’s still happening. And it’s completely inspiring.

I’ll leave you with a quote from Charles Darwin’s Origin of the Species. I like this quote because it is hard to read it and have negative prejudices towards this wondrous process from which we came into being.

“There is grandeur in this view of life, with its several powers, having originally been breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.”

Friday, October 21, 2011

color blindness

As you will pick up from future posts, I find avian coloration and color perception very engaging. Dr. Geoff Hill of Auburn is what you might call an expert in the area, and he inspired my interest along with many other students’ that came through his ornithology class.

Take a look at your surroundings right now. You see a mix of colors, all formed from a combination of different frequencies of electromagnetic radiation that fall within the visible light range. I know you’ve seen this before:

 

Our eyes, however, cannot detect all of these frequencies. Our color sensors- called cones- can actually only pick up three little ranges of color (red, green, and blue). Your cones tell your brain how much of those three colors, and in which combination, that they sense. Your brain does the rest. That’s right- purple is actually a figment of your imagination- your eye knows not what purple is.

But what if our eyes could pick up a fourth frequency with which our brains could then mix up colors? What would those colors look like? Maybe a really bright red. Or a rich blue. Electric green. No no no. We’re still thinking within our human color box. These new colors would be completely outside of what we know as visual experience. We cannot visualize them. Even if we built a special machine to project images with these new frequencies of radiation, our eyes simply do not have the machinery with which to see it. It is invisible to human eyes, and we will never know.

Perhaps our resources would be better directed towards breeding super-intelligent and literate birds so that they can describe the experience to us. That’s right- birds have a fourth cone from which to generate colors. They see ultra-violet light: that same elusive and abstract energy that we know to cause melanoma and plants to grow. They can see it. They see the designs on flowers that are invisible to us. They also see designs on each other that are invisible to us.

You see a brown bird with simple white streaks on its breast. Big deal. But if a third bird party views our brown and white friend, it may see flecks of the most unimaginable color dancing across its feathers in intricate patterns. And we will never know what it looks like.

It seems silly that we as a species can be so innovative, but we simply cannot find a way around our ignorance of this vivid color world that exists around us.

For exploration: 

Thursday, October 20, 2011

Intro

I’ve been playing around with the idea of starting a blog for a while. Not so much a personal blog (my personal life is hardly interesting even to me), but rather a science blog. I’ve put off beginning one, as I always wind up asking myself “who are you to write about science? You, Claire Floyd, are no scientist.” But I’ll tell you what I am. I’m a zoology student/graduate with a healthy dose of curiosity. I was lucky enough to learn from some of the most accomplished biologists in the field, and I learned enough interesting things to last a lifetime (or at least until I run out of ideas for blog posts).

During my time in college, I dabbled in the research circuit. And let me tell you folks, there is cool stuff happening there. You would never know it, though. It is clouded with scary statistics, unreadable journals, and words that have way too many syllables. A gap exists between the academics and the normal people. Science is for humanity, not just Joe Smith, Ph D and his dorky cronies. This blog is a small effort to close this gap.

Stay tuned and get ready. Biology comin’ atcha.