Ticked off

The thing that I sort of already knew but learned again just now is that the "bad" ticks, the deer ticks that can carry Lyme disease, are really quite tiny, which means that the slightly larger one I just discovered on my ankle is a wood tick, and even if I didn't get all of it out (I'm pretty sure I did but it's hard to tell), it's probably just icky and not medically dangerous.

They can only count to 8.

A vague train of thought, inspired by Joshua Holden's comment on the last post, has led me to the knowledge that ticks do not have fingers.  Thanks a lot, Josh.

Instead, their jointed legs end in a segment called the tarsus.  Most insects have multiple claws on the end of the tarsus (or pretarsus in some cases) called ungues (singular unguis)-- the typical ant could probably count to twelve, if it could count--  but the tick (not an insect) apparently lacks these.

In compensation, it does have something called the Haller's Organ, which is a sort of combination nose/thermometer/CO₂ detector that helps it find suitable... targets, shall we say.

Still blecch.

Dogs and Cats Living Together

Cheetahs are apparently kind of finicky when it comes to breeding.  Not breeding as in pedigree, but as in the actual act of mating.  They're very skittish, and especially when they've been raised in captivity, they don't socialize very well with other cheetahs.

They do, on the other hand, get along pretty well with dogs.  So much so that some zoos are giving the cheetahs pet dogs (or possibly the other way around).  The dogs reassure the cheetahs, reducing their stress levels, and help them feel more confident when introduced to potential breeding partners.

The one drawback to the process is that the dogs (despite sometimes being outweighed by a factor of 4 to 1) almost inevitably become the dominant part of the relationship.  They spend a lot of time with the cats, but they also have to spend a lot of time socializing with other people and dogs.  Feeding time especially-- as Janet Rose-Hinostroza, animal training supervisor at the San Diego Zoo Safari Park is quoted in the source article as saying, "If they ate together there would be one really fat dog and a really skinny cheetah."

Primary source: http://www.huffingtonpost.com/2013/02/12/companion-dogs-cheetahs-friendship-zoos_n_2667033.html

Argentinian ants

Once upon a time (as the story so often goes), there was a small colony of ants.  These ants lived in a somewhat unusual place, at least as far as ants go.  It didn't seem that unusual at first glance, perhaps-- simply a little chunk of floodplain in Argentina where a few rivers converged.  But that flooding meant that the ants were regularly washed out of their nests.

One side effect of this regular displacement is that the weaker, slower ants were weeded out fairly rapidly.  The rest relatively quickly evolved a somewhat more aggressive approach to their neighboring colonies.  You see, normally, ants aren't completely xenophobic.  They'll capture enemy ants, add them to their colony, sometimes mate with them, etc.  This means that the genetic makeup of the colony will slowly drift over time, which is generally a good thing for the species.  However, these Argentinian ants, bred by the rising waters for exceptional fierceness, simply don't do that.  When they meet an enemy ant?  They kill it.  To death.

All of which would be a minor entomological curiosity, except that sometime, back in the 1800s, a few of these ants made their way onto a ship, and were carried up from Argentina to New Orleans, where they started a new colony.  And started killing.  And spreading.  And remember, no fraternizing with the enemy!  So (and here's where it starts getting really interesting) these newly spreading colonies maintained the same basic genetic makeup as the original.  If an Argentinian ant from the motherland meets one from Louisiana?  They recognize each other, and coexist.  Genetic purity FTW.

And now, since they're so very aggressive, they've spread over pretty much the entire globe.  There are Argentinian ants everywhere, all more or less part of the same supercolony.

Primary source: http://www.radiolab.org/blogs/radiolab-blog/2012/jul/30/ants/

Give them the finger (no, the other one)

As a rule of thumb (ha ha), in men the index finger is shorter than the ring finger, and in women the index finger is longer than the ring finger.

This appears (at least in preliminary experiments with other mammals) to be due to hormonal balances in utero, to wit androgen, testosterone et al..  This means that many other sex-linked traits (biological ones, not cultural) can be correlated to finger length-- for example, one study* supposedly found that women with shorter index fingers (normally a "masculine" trait) were less likely to get lost.

*I don't have a reference; the Scientific American article just said "studies have found" and went on from there.  And now that I look at it, I'm REALLY damn skeptical.  I couldn't track down the actual study, but Wikipedia, funnily enough, does have an impressive list of links to other studies involving second/fourth finger ratios, such as this one (http://www.ehbonline.org/article/S1090-5138(99)00026-4/abstract) investigating musical ability.

DNAbc's

I've known since high school biology classes that all DNA is made up of four different chemicals, represented by the letters A, C, G, and T.  These can be put together in different sequences, making up the genetic diversity that keeps us all from looking like Pee Wee Herman, or Jeremy Clarkson, or [insert name of goofy-looking individual here].

The science of genetic engineering involves, among many other things, the careful rearranging of these components in different ways and orders, to create various effects.  This is still fairly straightforward, at least in principle-- it's terribly difficult in practice.  In fact, genetic manipulation usually happens on a much higher level, with the addition/removal/replacement of much larger complete sequences, or even entire chromosomes (which can contain well upwards of 100,000 nucleotides, the elements built out of those basic four chemicals).  As an interesting side note, apparently scientists in 2010 created an entire artificial genome from scratch, and successfully added it to an empty cell, creating the first ever completely artificial life form¹.

At any rate, things have gotten even more complicated.  Scientists are now starting to create nucleotide analogues that can be inserted into DNA sequences, allowing for even weirder possibilities².  They might not necessarily do anything radically different from the existing ones, but if nothing else it allows for some interesting artistic possibilities.  If we can add more letters to the genetic code, we might someday get poems written in a grain of rice, or designer crops with EULAs written right into their DNA.  GATGGACTTATTCATHEUSERAGREESTOTHEFOLLOWING...

¹http://www.sciencemag.org/content/329/5987/52

²http://www.newscientist.com/article/dn13252-artificial-letters-added-to-lifes-alphabet.html