Weekend Reading June 28

For those of you who think dinosaurs are less cool and scary since they have feathers - meet the deadly cassowary!

http://www.outsideonline.com/outdoor-adventure/nature/Ways-to-Die-in-the-Wild-Cassowary-Bird.html

Father's Genetic Quest to find out what was wrong with his daughter - what the human genome project makes possible - now with at home sequencing!

http://www.nature.com/news/father-s-genetic-quest-pays-off-1.13269

Sometimes even scientists are fooled by "everyone knows."  Someone finally checked and found out that  Komodo Dragons are venomous.

http://phenomena.nationalgeographic.com/2013/06/27/the-myth-of-the-komodo-dragons-dirty-mouth/

Most psychological studies are done on WEIRD people - Western, educated, from industrialized rich democratic countries.  Why this is a problem.

http://io9.com/rich-educated-westerners-could-be-skewing-social-scien-589231140

CSI:  Real Life.  Unlike on television most forensic scientists cannot look at plant samples and help the police find the location where a person or car picked up trace evidence. It takes a specialist to do that and most police departments (even the FBI!) don't have the kind of funding to hire a professional plant bit identifier (that's the technical job title).  In this link the botanists from the Field Museum help police narrow down the location where a murder suspect might have buried a body.

http://www.suntimes.com/news/sneed/20987878-452/field-museum-scientists-search-for-baby-kate.html

Bad Science Journalism

Part of a headline from a recent news story "Scientists say plants good at math."

Um.  No.

The story goes on to say that plants adjust their energy consumption at night depending on how much excess energy they managed to store during the day (remember:  plants need sunlight to produce energy through photosynthesis, less sunlight = less energy).

The actual scientific report shows that a specific plant, Arabidopsis, uses about 95% of its energy stores overnight, even if the night comes early (they can be grown under artificial lights to control day and night cycle length).

I read the article.  There is a lot of higher level math that I didn't wade through that looks at energy storage and expected time of dawn so I can't say that I really understood the gist of the article.  It seems like the plant can tell how much energy it has in storage and can adjust it's metabolism accordingly.

That is interesting, but does that mean the plant is doing math?

Plants don't have nervous tissue.  That means no brain.  Plants don't have fingers to punch numbers into calculators or a computer.  They can't tell the difference between one penny and one hundred pennies.  So how is this system working?

I'm not sure (as I said, I couldn't understand the article myself) but here's my (simplified) guess based on my understanding of molecular biology.

Proteins involved in metabolism have to interact with stored energy (a carbohydrate) within a cell.  The more carbohydrate that is available the more likely it is that a carbohydrate molecule will come in contact with the necessary protein. 

Imagine a bunch of kids on a soccer field.  It there is one ball each child's chance of kicking the ball is limited.  If there are a dozen ball them more balls will be kicked.  If there are a hundred then all the little kids will be able to kick balls nearly continuously.

In a cell if there is little carbohydrate available there will be fewer interactions with the metabolic protein.  If there is more carbohydrate available there will be more interactions with the metabolic proteins.  The rate of "kicking" (metabolism) will be affected by how much carbohydrate (balls) is available.

tl:dr:  No, plants can't do math.  

I am a scientist and I couldn't understand the article, how could someone who didn't study science get it right?

Science journalism done by journalists sometimes get the story wrong.

Arabadopsis thaliana from Wikimedia Commons, image by Reo On

Look, it's a bee, no, it's a wasp, no it's a MIMIC

I was out in my garden this week, trying to photograph some unusual pollinators for National Pollinator Week when I observed something different.  What I assumed was a bee perched on a leaf took off and attacked one of the [much larger] bumblebees!

I didn't get a good photo but here it is.

Predatory bee mimic

Lots of different species look like bees; flies in particular like to mimic bees.  Most of these mimics also function as pollinators.  Since bees sting looking and acting like a bee gets you a free pass from MOST predators.  At least against predators that don't specialize in stinging insects.

Another bee mimic, this one going for the nectar 

But there are predators who also mimic bees.  The excellent photographer, Alexander Wild, photographed a bee mimicking robber fly who successfully caught a bee for dinner [click on his name for some excellent insect photography].

My mystery predator?  No breakfast while I watched.  The bumblebees were too large for it and none of the smaller bees had gotten out of bed yet.  

Weekend Reading - June 21

If you look at nothing else this weekend - look at this essay:  Evolution is the only natural explanation.  If you find it's TL at least scroll down and read the part about colors - it ties in with my post on What is a Species.

http://ecodevoevo.blogspot.com/2013/06/evolution-is-only-natural-explanation.html

Great essay by a climate scientist on how to answer the question "Are We Screwed?"

http://www.stanford.edu/group/anthropocene/cgi-bin/wordpress/essay-how-am-i-supposed-to-answer-are-we-screwed/

In biology I teach how mitochondria in our cells originated as a symbiotic bacteria.  Now the citrus mealybug makes that look tame.  It contains organelles and genes from at least SIX DIFFERENT types of organism!  Students planning to take me in the fall of 2014 prepare to have the gob smacked out of you!

http://phenomena.nationalgeographic.com/2013/06/20/snug-as-a-bug-in-a-bug-in-a-bug/

Gibbons (an evolutionary cousin of ours) sometimes horse around.  Like this one, tightrope walking a bridge railing (video).

http://io9.com/this-is-a-gibbon-tightroping-across-a-perfectly-good-br-513431813

Blue whales can consume half a million calories in one mouthful.  And this enormous animal eats tiny krill.  Wow.

http://phenomena.nationalgeographic.com/2010/12/09/blue-whales-can-eat-half-a-million-calories-in-a-single-mouthful/#comment-55002

Don't read this next link if you're squeamish.

http://phenomena.nationalgeographic.com/2012/08/31/everything-you-never-wanted-to-know-about-the-mites-that-eat-crawl-and-have-sex-on-your-face/

A crab named after David Hasselhoff?  It lives at thermal vents deep under the ocean and has been spreading to new areas very quickly.

http://www.bbc.co.uk/news/science-environment-22952728

Weekend Reading June 4

Right in line with my recent post about the difficulty in defining "species" the great Carl Zimmer one ups me with a story on a "species" of poison arrow frog.

http://phenomena.nationalgeographic.com/2013/06/12/poison-camouflage-and-the-rainbow-of-evolution/

Lots of animals are capable of producing fluorescent light.  Lightning bugs are the first animal that comes to mind for most of us in North America, other parts of the world have glowworms, jellyfish, or bioluminescence in the water.  Deep sea fish can also glow under certain conditions but they do so by using symbiotic bacteria.  Now the first vertebrate organism (vertebrate means they have a backbone) that can fluoresce has been found - a Freshwater Eel.  The exciting part of the story is in the biochemistry but there is a really neat photo in this link:

http://www.nature.com/news/first-fluorescent-protein-identified-in-a-vertebrate-1.13190

Have you heard about Colony Collapse Disorder and the Disappearing Bees?  While there is still a lot of debate about what is causing the decline in bee populations this link shows one very clear problem.

http://myrmecos.net/2013/03/21/an-aerial-view-of-the-problem/

What If?  answers the question what would happen to the Earth if the sun suddenly switched off?  Be sure to hover your pointer over images for more snarky goodness.

http://what-if.xkcd.com/49/

Here are some good photos of a caterpillar who keeps the exoskeleton of old heads when it molts.  Even I think this is a bit creepy.

http://www.flickr.com/photos/colinhutton/8419407107/

The Definition of a Species

If you ask the average woman on the street how to define "species" you will get an answer something like "different types of animals."

If you ask one of my students you will (I hope) get something like "a group of individuals with similar physical and behavioral traits that are capable of breeding with each other and producing fertile offspring."

If you ask a biologist the answer becomes a bit more complicated.

There is no good answer.  The definition I use for class is the best working definition I have found.  But Nature does not color within the lines.  In fact when you ask Nature to color inside the lines Nature replies "but the lines make up a princess and I want to draw a tiger."

Let's look at Gulls as an example of why the definition of species is such a hard concept to define.

Here is a picture of a gull.

If you ask the average woman on the street what this is a picture of she will say "a seagull."

Ask an avid birder and he will say "a Herring Gull"

Ask a snobby birder (a small subset of birders) and he will answer "a mature adult Larus smithsonianus," or maybe "an adult HERG."

Let's try another picture.

Bird on the right - another Herring Gull, bird on the left is a Lesser Black Backed Gull (Larus fuscus).

Clearing distinct species, right?  I mean one has a light grey back and one has a dark grey back.

Well....  Yes, pretty much everyone agrees that the Lesser Black Backed Gull is a different species than the Herring Gull.  But look a the "latin" or scientific names and you see they both contain Larus.  This means the two species are somewhat related.

Ok.  Bear with me.  One more.

Average Woman on the Street:  "I know this one - it's a Herring Gull!"

Good birder goes "Herr... wait... somethings not quite right..."

Did you notice the legs?  In the Herring Gull they are pink, but this guy?  They're kind of yellow.  Huh.  A different species?

Not quite.  The consensus is that this is a hybrid between the Lesser Black Backed Gull and the Herring Gull.  These hybrids are fertile.

So are the Herring Gull and the Lesser Black Backed two different species or just one?

Oh, it is SO much more complicated that.  These are two (three?) examples of the "Larus gull complex;"  a group of different species that are capable of interbreeding and producing offspring that can then breed with other Larus gulls.  Originally thought to be a Ring Species they are now considered to be more complicated than that.  

These are birds with distinctive physical characteristics and different behaviors that are genetically close enough to hybridize and produce fertile offspring.  Multiple species?  A single species with a lot of diversity? 

We try to put these gulls into neat and tidy boxes marked species and Nature just laughs.