Tag Archives: biology

My spot, your spot.

I grew up on an island with seven million other people. Let’s just say it was difficult to find a spot to call your own. One day, as a youngin’ exploring the world on my bike, I broke off a path that ran along Sunrise highway and continued on down a hiking trail that snaked along a waterway in the local state park. I eventually came to a small clearing, sat down, and heard the weirdest thing. Nobody. No cars, no lawnmowers, no people. Just the birds and the chipmunks and the occasional splash of a fish.

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I felt as if I had stumbled on secret treasure. I spent a lot of time at this spot over my formative years, reading and thinking and being alone with my little patch of Long Island wilderness.

Before I left town for college I carved a “V” into the tree next to the water and said goodbye. While at college, I decided to major in biology, a decision shaped by my time out in the woods watching nature. I even wrote an essay about this spot for my freshmen writing class.

That biology major took on a life of its own, turning into an adventure through states, labs, and disciplines, and eventually resulting in a PhD from a zoology department and a dissertation on cancer and aging.
Last weekend Begum and I were visiting my parents and we decided to go for a quick hike before the ferry back to CT. A rush of memories came back, and I ran along this trail explaining my spot to her. She eventually found the V for me.

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Both of these images are from June 2017

It was the first time in over a decade that I set foot in this clearing. Needless to say, it was a powerful experience, and it sparked a bout of retrospection that, thankfully, I have been happy to ride.
I said a thank you, and another goodbye, and we ran to catch our ferry.

This summer, I hope you go out and explore, and find your own spot.

Dragonflies are awesome.

Alright, so my wife and I both think dragonflies are really cool. We never really thought about exactly why we think this, it’s just this inherent neatness about them. Maybe it’s how they hover like brightly colored silent helicopters and then quickly dart about like… I don’t know, some sort of alien spacecraft. And, unlike some of our other backyard insect friends (I’m talking about mosquitoes and red imported fire ants, both of which seem to have an affinity for my skin in particular), dragonflies don’t bother us.

This last weekend I was fortunate enough to have a dragonfly interaction that got me falling down the wikipedia rabbit hole learning about our flying friends, so I figured I’d share some of what I found here. First, for the fateful interaction:

I was grilling up a batch of beer in preparation for the summer…

You read that right. Cannataro’s Brewery Summer Saison will go on tap June 2015.

… and I was joined by a male blue dasher!

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He hung out for a while, flew to different perches, and even let me get a few close-ups.

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Smiling for the camera. Which, by the way, was just my cell phone (galaxy s4).

Eventually my wort was ready to start cooling and he was done patrolling the garden so we exchanged our goodbyes and went our separate ways.  Little did I know the carnage that was awaiting me the next morning. Warning, dear reader, the next image is graphic.

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My dragonfly friend had been decapitated! By one of his own! Well, kind of. That new, green, living dragonfly is (I believe) a female eastern pondhawk. After I took that picture she flew off, taking the body with her, leaving just his head as evidence. Woah. Talk about cool backyard biology! Down the wikipedia rabbit hole I went. Time for some rapid fire fun dragonfly facts.

Dragonflies have been on Earth in pretty much their present form for over 300 million years. In fact, the largest insect to ever exist was an ancient dragonfly (with an estimated wingspan of 28 inches!). They can spend years in their underwater nymph form, which has extending and retractile lower jaws (remind you of any alien characters?) and can feed on vertebrates (small fish, tadpoles) and mosquito larvae (thank you).

The adults enjoy mosquitoes as well (told you they were awesome).

The nymph crawls out of the water and transforms directly into the adult in a process called ecdysis. They have a unique mating system where the male grabs the female behind her head with the claspers at the end of his abdomen and they form a heart-shaped mating pair. Their wings are self-cleaning and water repellant due to the lotus effect. I can go on and on, but if you want to learn more you should check out this video:

So next time you look at a dragonfly think about how you’re looking at the 300 million year old body plan of a ruthless killing machine with a 95% hunting success rate. Dragonflies are awesome!

 

January 2015 fun facts

Woah, I’m way backlogged on blog posts! Don’t worry, I have some cool stuff in the works and I’ll share soon. In the meantime check out some of the science I’ve been starting my classes off with this month.

Aging research: blood to blood – scientists can splice animals together by creating a wound in each animal and sewing them together- their natural wound healing mechanisms join their bodies and their blood (it’s called parabiosis)! If you splice an old animal to a young one the tissue in the old animal gets “rejuvenated” by the young animal’s blood.  Sounds like the premise for a horror movie.

Scientists have discovered a new antibiotic that kills pathogens without detectable resistance.

Scientists have discovered that tumor cells can actually acquire previously lost DNA (in this case mitochondrial) from “normal” cells, and that the newly acquired DNA restores missing function. Think about that. Somatic cells (or cells that were once deemed somatic but now have become tumor cells) can horizontally transfer DNA. Biology textbooks get rewritten every day.

And, of course, I can’t introduce metabolic scaling and not discuss the invariance of heartbeats.

Enjoy!

Mind controlling parasites- how sci-fi are zombies anyway?

 

Halloween weekend is drawing to a close, and as I type this (looking out a coffee shop window) I can still see the zombie makeup on the faces of those passing by. It’s understandable why the whole zombie thing can be pretty terrifying. In the movies the protagonist usually watches their once fully autonomous friends and loved ones fall prey to some microscopic parasite and become a mindless vessel, obeying the will of their neural captors, tasked with ensuring the survival of the parasite and oblivious to their own health. Good thing it’s science fiction! Right? Well, anyone studying parasitology can tell you that in some cases it’s less fiction and more science.

Whenever I teach the lab on species interaction I always spend a good bit of time on mind controlling parasites. First off- they’re just cool. Plus, there’s a lot of captivating videos out there! One of my favorite being:

(p.s. larva emerging from a caterpillar body below, viewer discretion advised!)

Great music and sound effects aside, it’s always interesting and sort of mind-blowing to see the caterpillar actively defend the larva that just busted through its skin. It really gives you a sense of just how possessed an organism can become at the whim of a parasite. Another zombie-state-inducing parasite infects snails:

And another favorite, the inspiration for the zombie-survival game The Last of Us, infects and alters the behavior of entire forests full of insects:

 

Ok, so mind controlling parasites might actually be all around us, but at least they only infect invertebrates. Right?! Well, no.

Rats have a natural (and understandable) aversion to cats. When they smell cat urine they feel fear and head in the other direction. However, rats infected with the protozoan Toxoplasma gondii, which only reproduces in the cat intestine, are actually drawn to cat urine. The parasite hijacks the sexual arousal pathway in the rat brain, and instead of feeling fear the rat feels sexual attraction to the cat odor. So, just like the snails in the video above, the rats search out their natural predators for the benefit of their parasite.

 

Ok, so mind controlling parasites can infect and manipulate the behavior of mammals as well. But, certainly humans, with their giant and complex brains, don’t have to worry about being influenced and controlled by the whims of a tiny microscopic organism. Right?! Well…

I have a habit of bringing up the universe that exists within multicellular organisms. It’s easy to think of this as a one way interaction- a large organism goes about their business and the little organisms tag along for the ride. But the survival and wellbeing of the microbiome is extremely important- so important that hosts even synthesize food for their microbiome during periods of illness to ensure that their microbial friends stay happy.

Is it possible that some of our microbial friends could be manipulating our behavior for their benefit? Some scientists have recently suggested that might be the case- we might be at the whims of a microbial puppet master. More research is needed to test these hypotheses, but I look forward to the day where taking a microbe-filled pill can change my appetite for the better and bolster my microbiome.

Outside of our bacterial microbiome, we also house a vast virome. Research published in PNAS this week has shown that humans can be infected with an algal virus, and this virus was associated with a 10% decrease in performance on visual processing exams. Additionally, mice infected with the virus took about 10% longer to navigate a maze and explored 20% less.

So, maybe we’re not so autonomous after all. Spooky! Happy Halloween!

Will the real Banana Spider please stand up?

I’ve encountered two different species of giant (subjective classification based on my previous New-York-State-only spider exposure) orb weaver spiders while living in Gainesville (and one non-orb weaver!). Both of which have been referred to as a ‘banana spider’. So, who are these spiders anyway, and which one is really the true banana spider?

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Exhibit A- picture taken at the La Chua trail.

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Exhibit B- picture taken in my front yard. (notice the flash reflection in the front eyes!)

It turns out that there are a few spiders referred to as a banana spider. However, only one of those spiders is pictured above, and it’s Exhibit B- the Golden Orb-Weaver (Nephila clavipes). Exhibit A, with its characteristic zigzag web, is commonly referred to as the Yellow Garden Spider (Argiope aurantia).

Apparently the Golden Orb-Weaver was recently moved out of the Orb-Weaver family and placed in the Nephilidae family because their webs weren’t sophisticated enough. Bummer!

Regardless of species name and web sophistication, if there’s one thing I’ve learned while living in Florida, it’s watch where you walk…

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Banana spider waiting to catch a low flying plane

 

Awesome camouflage

Staying in the lab is tough when you live in the sunshine state. I mean, at SUNY Geneseo it was easier- the lab served as a warm refuge against those Western NY winds and clouds. So every once and again I’ll find a break in the Floridian sunshowers and bring my work outside. However, as any biologist can tell you, work is impossible outside because you always get distracted by some cool critter crawling by your laptop. Case in point: last time I tried this I noticed a little pile of moss moving across the table…

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… so of course I flipped it over…

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…and found legs! (Woah, I need to find out what this is.) Further investigation revealed impressive mandibles and a set of sticky spines:

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It looked very similar to an antlion, which is the larval form of a certain family of lacewing. Antlions are awesome in their own right, they form little trenches in the sand and eat ants that fall into their trap. I teach an intro bio lab on the spatial distribution of organisms, and I always take the students outside to hunt for antlions (they are typically (spoiler) clumped together in sandy spots under the eaves of buildings). And I always show this video:

Anyway, it turns out that critter I found was also a larval lacewing! Certain species have sticky spines on their back that trap debris and help the larva blend in with their environment. This isn’t a new tactic- scientists have found a 110 million year old larval lacewing trapped in amber that has fern trichomes stuck on its back. How cool is that?! (Another spoiler: very)

And such is the curse of the biologist- go outside to write and in minutes you are a few Wikipedia pages deep classifying insects.

What’s in a species?

Take two biologists, sit them down, give them a few beers each, and then ask them to define the word “species”. Chances are you’re in for a colorful discussion. “Species” is one of those concepts that made perfect sense in high school, got fuzzy in college, and is something biology graduate students like to debate on the weekends.

Person A: It’s easy, right? If two organisms can create viable offspring, they are part of the same species.

Person B: Well, what about hybrids? You know, like when a horse and a donkey (clearly different species) mate and produce viable mules.

Person A: Well, mules are (usually) sterile, so that doesn’t count.

Person B: Ok, how about the viable and fertile offspring produced when Canids mate, like dogs and wolves or coyotes and wolves?

Person A: But those are recently diverged groups, I’d argue that they were actually subspecies of the same species (since they can produce viable fertile offspring, they’d be a subspecies by definition).

Person B: Alright Linnaeus, now you’re rewriting taxonomy. So you’re saying that as long as two organisms can produce fertile offspring, they’re members of the same species?

Person A: Right, but we can still define them into separate sub-species.

Person B: What about when organisms from two different genera produce viable offspring, like Fatshedera lizei ? 

Person A: Are the offspring fertile?

Person B: Well their are some reports that…

Person A: That’s a plant anyway, the rules are different for plants.

Person B: Wait, what are the rules for “species” in asexual organisms, especially when genetic code can be passed on by horizontal gene transfer? And what about cancer as a speciation event? You know, the idea that a tumor has a separate genome from its host so it should be thought of as a different species.

Person A: No way, man. Cancers are formed from and completely dependent on their host. It’s just an extension of a single organism.

Person B: Not necessarily! The Tasmanian Devil facial tumors are spread between hosts by contact. Why shouldn’t we consider those cells a unique pathogen, no different than a virus spread between hosts? And how should we classify that ‘organism’?

Person A: Are viruses even considered alive?

Person A+B: …I think I need another drink.

Yes, I’ve had similar conversations over the years as a biology graduate student. I was reminded of the species debate after reading about the “out of Africa” concept and human speciation, and whether or not we interbred with members of other hominid groups (and, what that means for the definition of our species).