Baby geniuses: young guppies show number skills

I have vague memories of the first time I counted to a hundred. It felt like one of those landmarks like tying your shoes for yourself the first time, or riding the bicycle more than a few feet without the training wheels or dad holding you up.

Of course, I don't come anywhere near Adam Spencer:

Once when I was about 7, I counted to 10,000 just to check the numbers didn't run out before then #NerdConfessions

Counting large numbers is not something that comes easily for us humans. A new paper claims this little guy, a baby guppy, may be a superior number cruncher as soon as it pops out of mama’s belly:

A couple of years ago, I reported on a paper that looked at the development of “counting” ability in guppies. In that paper, they claimed that it took about 40 days for guppies to develop the sort of ability to distinguish numbers that they had as adults. Now, the same team is back, testing very young guppies again, but this time using new methods.

The team asked these tiny guppies if they recognized numbers of things by showing animals dots while they have them food. Here are the three stimuli the team used.

Both A and B differ in the number of spots, but A also differs in the average sizes of those spots (which the authors call a “continuous variable). C differs in size, but not in the number. This is try to control for the fact that when you change number of things, you also change many other factors, like amount of area reflecting light, etc.

The authors then measured the amount of time the guppies spent near each set of dots as an indication of “preference”, on the assumption that the guppies are more likely to spend time near the dots where they got food if they learned certain dots meant food. If animals don’t learn where the food is, they may well not be able to tell the stimuli apart.

The authors place these pairs of dots at the end of the tank while fish are feeding when they were four and five days old. As a control, they either feed the fish food or just in a little water without food. On day six, they placed the babies in the tank to see which set of dots they gravitate to. On day seven, they repeat this, but flip the positions of the dots.

The fish were significantly more likely to be around the set of dots that promised food when they differed by number (A and B, above), but not when the dots varied in size. That said, the guppies were not great at this. The guppies got it right only 60% of the time, which is only a slight improvement on a coin toss.

However, the authors themselves admit that this paper is hard to compare with their previous one because the stimuli are so different. The previous paper used other live fish as the stimulus, not just static dots. They also note that this test is slightly different from other training tests, which generally ask the animal to do something even more specific than “hang out at one end of an aquarium.”

It is an interesting suggestion, though, that animals so small and so young can cope with differences in number. But I still think I’ll beat them at counting to a hundred.

Reference

Piffer L, Miletto Petrazzini ME, Agrillo C. 2013. Large number discrimination in newborn fish. PLOS ONE 8(4): e62466 DOI: 10.1371/journal.pone.0062466

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One fish, two fish... can fish count?

Picture by Shaojung on Flickr; used under a Creative Commons license.

New university one step closer

The bill proposal the creation of a new university in South Texas (including a medical school) passed unanimously in the House of Representatives a few moments ago. The only legislative step needed now is for Governor Rick Perry to sign the bill into law, which he said he would do.

This means my university will be changing and merging with other institutions and more stuff will expected from us.

Now what? In the words of Amy Pond... “Okay kid.... this is where it gets complicated.” 

There will soon be a zillion nitty gritty details to work out, which have so far been in short supply. 

Colour costs crickets

You probably don’t feel tired when you get a tan.

You probably think your friends feel more or less fatigued depending on whether they are dark skinned or fair skinned (like myself).

We know that differences in colour are important lots of other species besides humans. They can play a big part in an animal’s ability to blend into the surrounding environment, for instance. What might be less appreciated is that being a certain colour might take energy. After all, many colours in animals are caused by pigments: specific molecules that animals have to make in their bodies. Some of those molecules could well depend on molecules that the animal has to get somehow, or make through a physiological process.

Melanin is just such a chemical. Melanin is a dark chemical in lost of insects, but one of the main compounds insects need to make it only comes in food. If you don’t get enough food, you can’t make enough melanin. A new paper by Roff and Fairbairn take this a step further, and asks if melanin might actually be costly for animals to make, with an eye towards evolutionary situations. For instance, how big a benefit in dark colour would there have to be for you to spend the energy to make more dark stuff?

They test this in a clever way. Rather than looking at different colour types of one species, they look at changes in colour of a single species, a sand cricket (Gryllus firmus; above right). When these crickets shed their skeleton, they are very lightly coloured (right): there is no melanin in their new skeleton for a while until it hardens up.

They reasoned that if making all this melanin was costly to the cricket, then crickets with less melanin should have more of some other feature, like the gonads. And that’s what they found. The bigger the gonads in cricket, the less melanin they had. This degree of melanization was highly heritable, too (a score of 0.61, where 0 is not influenced by genes, and 1 is completely determined by genes).

This in no way suggests that this means you shouldn’t tan. Yet.

Reference

Roff DA. & Fairbairn DJ. 2013. The costs of being dark: the genetic basis of melanism and its association with fitness-related traits in the sand cricket. Journal of Evolutionary Biology: in press. DOI: 10.1111/jeb.12150

Moth picture from here; cricket picture from here; cricket molt from here.

Sudden realization

I genuinely had this thought walking home last night...

Comments for first half of May 2013

The Singular Scientist examines oft-given public speaking advice to calm nerves before a presentation.

Small Pond Science is looking for summer reading. If you’re an educator, I like Design for How People Learn.

I really liked Doctor Becca’s reflections on being mid-way through the tenure process, especially the bit about fame. Also excellent is Small Pond Science’s reaction to that.

Love Girls Are Geeks advice on how to talk with a scientist.

“Offshore” journals

Jeffrey Beall is doing much to draw attention to issues surrounding the validity of new journals. He is in the news today because a publisher is threatening to sue him for one billion (yes, billion with a b) dollars.

But I wanted to comment about a post from April about Hindawi Publishing. Beall ends:

Is this the future of scholarly publishing, dumbed down and offshore?

The “offshore” comment has a slightly snobbish overtone. It implies that, “Of course, some places simply can’t produce good scholarship.” I am sensitive to this, since I realized my own posts made similar jabs at the national origin of many journals. I realized that was a little unfair.

I agree that researchers some countries do face bigger challenges in producing top-quality scholarship. It could be due to lack of infrastructure, distorted publishing incentives, or an overly cliquish academic culture. But such challenges need to be examined and spelled out, not made in an offhand way.

External links

Hindawi’s Profit Margin is Higher than Elsevier’s
Publisher Threatens to Sue Blogger for $1-Billion

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As Nigeria is to banking, India is to science publishing
Science Online 2013 appetizer: Open access or vanity press?
The center of knowledge

Tuesday Crustie: Macro

The photographer identifies this as Orconectes, though not which species.

Photo by Bee Nouveau on Flickr; used under a Creative Commons license.

Continuing education

“I just want to continue my education.”

I’ve heard this from a few prospective grad students. I understand why they would say they want to continue their education when they’re asked why they want to go to grad school. I imagine for their entire lives, they have probably been encouraged to stay in school. For their entire lives, they have probably been told degrees are a pathway to greater professional success. For their entire lives, education has been an unalloyed good.

But “continuing education” is not a good reason to go to grad school. At the end of a bachelor’s degree, honestly, you should have a pretty darn good idea about how to continue educating yourself. That’s the point of a liberal arts degree. Grad school is a specific education with a specific purpose. Do it if you need the degree for a specific career, or if you love the subject.

I have yet to hear someone who says, “I just want to continue my education” give a good answer if they get asked, “Why?” They often have no plan, and little understanding of what grad school entails.

Scientific writing seminar

This is a talk I gave to undergraduate research students at the STEM Center earlier today. Come for the tips, stay for the bad jokes!


Additional, 11 May 2013: Now you can follow along with the slides on Slideshare!