Posts in Category: Science

Cause Of The Biggest Extinction Event Ever

Posted Jun 3rd, 2006 at 12:59 pm in Nature, Science | Comments Off

The Cretaceous-Tertiary mass extinction event is perhaps the most famous in the mind of the public. It wiped out the dinosaurs. The evidence points to a giant asteroid, with the famous impact crator found at Chicxulub (pronounced Cheek-sue-loob). Part of the impact crater lies on the Yucatan peninsula Mexico, and part of it lies underneath the Gulf of Mexico. In terms of biodiversity, it killed approximately 50% of the Earth’s families.

This pales in comparison to the Permian-Triassic mass extinction event, which wiped out over 90% of life in the oceans and 70% on land. It’s cause has been a great mystery.

In an article surfacing recently, scientists may have discovered the asteroid responsible. The results are preliminary, and only time will tell how this progresses, but the finding is quite interesting.

An apparent crater as big as Ohio has been found in Antarctica. Scientists think it was carved by a space rock that caused the greatest mass extinction on Earth, 250 million years ago.

The crater, buried beneath a half-mile (1 kilometer) of ice and discovered by some serious airborne and satellite sleuthing, is more than twice as big as the one involved in the demise of the dinosaurs.

This would have been at the time Antarctica was still a part of the southern super continent, Gondwanaland.

Personally, if an impact this size was responsible for the biggest extinction event in earth’s history, it’s likely to have been the first in a series of events that ultimately led to the demise of most of Earth’s life. The precise progression and details of this series may not be knowable, but the impact that started it all may have just been found.

We Biologists Are Weird People

Posted May 3rd, 2006 at 1:12 pm in Birding, Science | Comments Off

So this guy shows up at my blog, sends me a nice message, leaves a nice comment, and then practically pours salt in my wounds by posting pictures of him working with Kakapos. Like they’re pets!

And if that isn’t enough to make a birder / biologist jealous, he has the audacity to brag about his scars.

He also gave me a permant scar on my right hand (which I treasure) when he decided my hand was a good thing to grasp hold of.

Now I really don’t like him. A scar from the 8 pound night parrot? Are you kidding me? As Ike drukenly says in Tombstone, “Nobody’s that lucky!”

But the truth comes out. It’s in small print. You may have to squint to read it.

I may or may not have helped ensure a scar would remain by rubbing various irritants in…

While there’s a certain lack of integrity here, I can’t really blame him. Deep down I have to admit, I would have done exactly the same thing. And even worse, I’d tell everyone and anyone who would listen.

Pride in parasites, scars, wounds, and the like — we biologists are weird people.

Talk About Inspirational

Posted Apr 10th, 2006 at 9:40 pm in School, Science | 2 Comments

Every year Angelo State has an event called the Moon Lecture where they bring in a top rate scientist to speak on different issues. The night before the lectures, they have an informal BBQ where faculty and certain students can hear the life story of the speaker, meet them, and ask questions. Having just arrived at school, this was my first time to attend.

This year the speaker is Leroy Hood. (And see more on Wikipedia).

He’s a systems biologist who is credited with creating the DNA sequencer, amoung other things. All you lab rats out there who love looking at DNA sequences to study evolution have Dr. Hood to thank. He’s also been involved with the Human Genome Project, various immunology projects, and a host of other biotechnology projects.

He basically spoke of his childhood (grew up in Montana) and how his interest in science was nurtured by parents and childhood teachers. One of those high school teachers convinced him to attend Cal Tech, where he arrived in 1960. He said it was the biggest culture shock of his life. Upon arriving, his roommate asked him if he’d taken some course (cancer research? — I don’t remember). “Not only had I not taken the course, I’d never heard of it.” “You’re in big trouble then, you’re not going to make it,” his roommate responded. Dr. Hood said that his roommate had failed out the first semester from playing 20 hours of bridge a day. Though I’ve never played bridge, I get the idea that it would be an emmensely more enjoyable way to fail out of college than 20 hours of video games a day, as my peers do now.

He spoke of how accessible his professors at Cal Tech were. My jaw dropped when I heard some of his teachers his freshman year. Richard Feynman for physics, Linus Pauling for chemistry, and George Beadle for biology. He had the attention of every single person in the room.

Tomorrow he’ll be giving two lectures which I will attend. As I mentioned, his interest is systems biology. I think it’s essentially the question of how we manage the information we’re getting. When you think about the amount of information contained in the genome and the interactions going on in a biological system, we’ve gotten to the point where we need ways to condense that information and think about it conceptually. Dr. Hood mentioned that medical school was a big disappointment to him because of the rote memorization and the lack of conceptual interest. (Yeah, I personally call it the dark side of biology). I believe his talks will center upon the work being done in these areas.

I’ll take notes and present the highlights. I’m very much looking forward to it.

The Animals Know It’s Happening

Posted Mar 22nd, 2006 at 7:53 pm in Nature, Science | 2 Comments

I saw this story this morning, and as if to nudge me to blog about it, a reader sent the link in. The Washington Post has a story on global warming that’s worth reading. It’s nothing new, just more of the bleak picture of what we’re doing to the earth.

Now, I know there are doubters out there. And I know scientists occasionally get things wrong. And I also admit that this is not my area of expertise. But one of the things interesting about the story is that it hits upon biological changes to the warmer conditions. (Again, this is nothing new, we’ve been watching this happen for some time).

Fish and wildlife are following the retreating ice caps northward. Polar bears are losing the floes they need for hunting. Seals, unable to find stable ice, are hauling up on islands to give birth. Robins and barn owls and hornets, previously unknown so far north, are arriving in Arctic villages.

[...]

In this month’s issue of the journal Science, a team of U.S. and Canadian researchers said the Bering Sea was warming so much it was experiencing “a change from arctic to subarctic conditions.” Gray whales are heading north and walruses are starving, adrift on ice floes in water too deep for feeding. Warmer-water fish such as pollock and salmon are coming in, the researchers reported.

We’re seeing it in the die off of amphibians, in the expansion of species to higher elevations, in the earlier arrival of migrating birds returning to their nesting areas, and a thousand other places. One example taken by itself means nothing. But thousands of cases of organisms responding to their warming environment helps make a compelling case to what’s happening.

Answering Mark on Astrobiogeography

Posted Mar 21st, 2006 at 10:46 am in Science | 8 Comments

A person named Mark stopped by and left this comment on my post about astrobiogeography. He writes

If life is found somewhere else in this vast universe and it works just like life on earth what would that mean?

It’s an interesting question and I’m glad he asked it. I think it’s so interesting that I thought I’d give my answer in it’s own post (just so more people see it) than leaving a comment.

If life was found elsewhere that worked just like life on earth, it would cause the biggest uproar in the scientific community ever seen. Briefly, here are some imaginable scenarios I have off the top of my head.

  1. An exact replica of earth is found. The continents and the geology are the same. The fossils are the same. The exact same species exist with the same distributions, etc.

    Conclusion — special creation starts looking a whole lot more appealing.

    Let’s even go a step further. The people are the same, the religions are the same… I become a creationist. It doesn’t solve any problems about who the creator is, but it’s just about impossible to imagine a scenario like this happening, and if it did, I’m not sure you could explain it scientifically.

  2. Life is found that works just like life on earth. DNA, genetic code, etc. But the proteins being used to build everything, and the organisms themselves are completely different. Life may work the same way, but it looks nothing like what we’ve seen before.

    Conclusion — Couple of options here. The scientific one is that this completely overthrows our ideas about origins of life and how they happened. Perhaps life really can only exist this way. Under the right conditions, life evolves to work like it does on earth. Evolution then takes a different course in reponse to different environmental conditions.

    Metaphysically, you can decide that a creator set things up more than once to let them play out…

  3. Life works totally different. This is the overwhelming prediction based on what we know about life today. It could be as minor as a genetic code that’s just built differently. For example, you don’t have to have the same bases in DNA. For example, we use uracil in our RNA. It’s conceivable to imagine a genetic code built of different molecules. Or life could work completely different. Something so different that the rules are just unlike anything we’ve seen on earth.

    Conclusion — life evolved seperately at another location.

Number three is definitely the scientific prediction about what life would look like elsewhere. It would be something else if it turned out to be wrong.

Astrobiogeography

Posted Mar 10th, 2006 at 11:31 am in Science | 2 Comments

Scientists think they’ve found liquid water on Enceladus, one of Saturn’s moons. MSNBC has the details, along with commentary on why this is such a big deal.

One of the powerful arguments for evolution is what we call biogeography, the study of the distribution of species on earth. Marsupials are overwhelming concentrated in Australia; clustered around a few lakes in Africa, hundreds of species of small fish known as Cichlids have quickly evolved to fill an enormous range of niches, Pronghorn (and the handful of Pronghorn species known from the fossil record) are only found in North America.

This is the stuff of biogeography, a field credited to Alfred Russell Wallace, the other great evolutionary biologist that’s largely forgotten compared to Charles Darwin. The idea is that species aren’t distributed randomly, but rather their distribution reflects their evolutionary history.

So, if there’s water on Saturn’s moon Enceladus, there could be life. No one’s saying there is. Rather, this place just jumped to the forefront of where to look.

And what if there was life? The biggest reason scientists believe life evolved once on earth is that everything works the same way (more or less…). DNA has the same four base pairs in us as it does in bacteria. The assumption is that life elsewhere would work fundamentally differently from life on earth. Different chemical molecules, different “genetic codes”, etc. An example of life evolving twice, just within our own solar system, would give reason to believe that perhaps it’s not as rare as we think.

In this sense, the field would become astrobiogeography. Why does life on earth use DNA with A-T-C-G’s, why does life on Enceladus have a genetic code of proteins that fold special ways, and why does planet Mintorg have gaseous Namvats that reproduce by sending out frequency dependent waves of light. Since evolution as we know it is inseparable from genetics, it could work entirely different in other places or not even work at all.

Finding life elsewhere has major metaphysical implications too. Does life spring up commonly where ever conditions are suitable? For those that believe in a literal 6 days, the obvious question becomes, what day did He create Namvats…

Guess Who Just Got Published

Posted Mar 9th, 2006 at 10:32 am in Life in General, Science | 8 Comments

The blogging’s been slow lately as I’ve been trying to catch up with work and school in preparation for spring break. I do however have some exciting news to share.

I am now a published author of a scientific paper. Results of a Mammal Survey of the Tandayapa Valley, Ecuador has just been published in Occasional Papers of the Museum of Texas Tech University, Number 250. I conducted this survey with a professor and an Ecuadorian student in 2003.

Like Gregor Mendel, this work has been published in an obscure journal that no one will read. Unlike Mendel, no one will rediscover this paper 30 years from now to spawn a new field of science.

It’s a simple paper, entirely descriptive of what we found. Basically the area had never been surveyed before, so we extended the range (and/or known elevation) for a handful of species.

And while it’s not much to brag about, it is more of a contribution to science than intelligent design can claim in the last 20 years.

Satire on Ice

Posted Feb 23rd, 2006 at 10:30 am in Humor, Science | 3 Comments

What if all science was attacked like evolutionary biology? What if conspiracy theories and charges of coverups were more common place?

Pym van Meur over at the Panda’s Thumb, explores this issue by examing the controversy on why ice is slippery.

A little known secret is quickly growing into a worldwide scandal of unimaginable size and intensity: scientists do not know why ice is slippery. I am sure that many among you remember the textbook explanation that the pressure of the ice skate melts the ice and the skate slides on the water which then freezes. But now, the dedicated reporters of the New York Times have uncovered the scandal which is growing into what some claim to be the Waterloo for the Melting Ice Theory (MIT).

The Five Second Rule

Posted Feb 17th, 2006 at 3:19 pm in Humor, Science | Comments Off

Dang these scientists!!!! Is nothing sacred?

About Those Chicken Pox Parties

Posted Feb 15th, 2006 at 9:18 am in Science | Comments Off

Tara Smith has an interesting post over at Aetiology about chicken pox parties… They’re not nearly as harmless as some may have thought.

I know that many people still view chickenpox as “just a harmless childhood illness.” Sure, for many of us, that’s the case. So far, I’ve escaped with little more than a few scars on my forehead… However, there’s a very real possibility that I could develop shingles later in my life. Additionally, the wild virus just ain’t as benign as we’d like to think. It can cause severe pneumonia or encephalitis. Additionally, I mentioned here that deadly infections with the group A streptococcus are becoming more common. Guess what’s a major risk factor for these infections? Yep–chicken pox. Check out, for example, this manuscript on invasive group A strep disease in Alberta, Canada, which notes that “varicella virus infection preceded invasive GAS disease in 25% of children 8 years of age and under.” It has the potential to be much more than just an inconvenient itch.