the derb on jayman

here’s some high — much deserved! — praise for jayman from the derb! (^_^) much better reading than the last post (because the content is actually accurate!):

“John Derbyshire On JayMan — A Righteous Jamaican-American”

“JayMan writes about human nature, with particular attention to human differences. As such he has particular appeal to Us of the Cold Eye. That is to say, he’s a stone empiricist who scoffs at happy talk and wishful thinking about human nature, and goes to the research studies. Just a brief digression here on the nature and content of those studies.

“We are now at the point in our understanding where it is beyond dispute that all the interesting traits of human behavior, intelligence, and personality are heritable to some degree….

“Bill Maher, for example, in a TV spot about Amy Chua’s 2011 Tiger Mom book, swallowed the whole parenting-style-shapes-adults shtick. JayMan, who is a fan of Maher’s (more on this below) wrote Maher a long letter setting him straight. The letter is reproduced in the second post here.

“‘It is not at all surprising that bright, hard-working and successful parents would have bright, hard-working and successful children. It is the same reason that tall, freckled parents tend to have tall, freckled children: their genetic endowment. [Taming the ‘Tiger Mom’ and Tackling the Parenting Myth, November 16th, 2011]’

“Maher did not favor JayMan with a reply to his letter.

“Conservatives are even more clueless about the human sciences than liberals. It is for example a perennial theme in conservative social commentary that fatherlessness is the cause of much social dysfunction and many poor life outcomes. If only poor people could be persuaded to get married and stay married!

“Sounds nice, and gets your timid conservative commentator off the ‘racist’ hook, since ceteris paribus fatherlessness is much more common among blacks than nonblacks.

“But…’Happy talk!’ scoffs JayMan.

“‘Even if there was more marriage among those in the lower class, the next generation, having inherited all the same traits, would be no different. The poor outcomes of children who were raised in fatherless homes stem not from the much maligned single motherhood — in and of itself — but rather from the traits these children inherited from their parents, who were the type of individuals likely to have their children end up being raised by single mothers. [Liberalism, HBD, Population, and Solutions for the Future, June 1, 2012]’

“So the arrow of causation is not from fatherlessness to poor life outcomes: It is from certain features of the parental genomes inclining to single motherhood and pump’n’dump fatherhood, and thence, by genetic transmission, to similarly feckless offspring.

“This latter picture makes much more sense given what we know about the heritability of behavioral and personality characteristics. Which is a lot: JayMan has put together an excellent reference post, spelling it all out, with numerous links….”

read the whole thing @vdare! and for god’s sake, read jayman’s blog AND his twitter feed! first place i go every morning. (^_^)

edit: see also The Derb on the JayMan from jayman!

(note: comments do not require an email. jamaica!)


athletes and human biodiversity

you may have seen these howard schatz photos floating around on the internet the past couple of days. (if you did, you spend too much time online! — if you didn’t, you don’t spend enough time online!) i lifted the ones below from imgur.

all different sizes and shapes of people! neat! (^_^)

left to right: gymnastics, high jump (of course!), trampoline, high jump, triple jump, wrestling [click on images for LARGER views]:

howard schatz 01

long distance running, marathon (i love this guy!), decathalon, marathon (him, too!), running (800m):

howard schatz 02

rhythmic gymnastics (oww!!), sport aerobics (huh?), gymnastics, gymnastics, high jump (uh…yeah), gymnastics:

howard schatz 03

bodybuilding, weightlifting, weightlifting(!), rhythmic gymnastics, rhythmic gymnastics:

howard schatz 04

there’s more @imgur. and on howard schatz’s website.

previously: you, too, can become the fastest man on earth!

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plants are people, too!

ok, ok — so maybe they’re not really people, but they are pretty d*rn cool! no really!

bet ya didn’t know (or maybe you do) that they can tell if you’re wearing a red or a blue shirt. or that they know when the fruit of neighboring plants is ripe. or that they have short-term memory.

yes, short-term memory:

“As we saw back in chapter three, the Venus flytrap needs to know when an ideal meal is crawling across its leaves. Closing its trap requires a huge expense of energy, and reopening the trap can take several hours, so Dionaea only wants to spring closed when it’s sure that the dawdling insect visiting its surface is large enough to be worth its time. The large black hairs on their lobes allow the Venus flytraps to literally feel their prey, and they act as triggers that spring the trap closed when the proper prey makes its way across the trap. If the insect touches just one hair, the trap will not spring shut; but a large enough bug will likely touch two hairs within about twenty seconds, and that signal springs the Venus flytrap into action.

“We can look at this system as analogous to short-term memory. First, the flytrap encodes the information (forms the memory) that something (it doesn’t know what) has touched one of its hairs. Then it stores this information for a number of seconds (retains the memory) and finally retrieves this information (recalls the memory) once a second hair is touched. If a small ant takes a while to get from one hair to the next, the trap will have forgotten the first touch by the time the ant brushes up against the next hair. In other words, it loses the storage of the information, doesn’t close, and the ant happily meanders on. How does the plant encode and store the information from the unassuming bug’s encounter with the first hair? How does it remember the first touch in order to react upon the second…?

“In their [Dieter Hodick and Andreas Sievers] studies, they discovered that touching a trigger hair on the Venus flytrap causes an electric action potential that induces calcium channels to open in the trap (this coupling of action potentials and the opening of calcium channels is similar to the processes that occur during communication between human neurons), thus causing a rapid increase in the concentration of calcium ions.

“They proposed that the trap requires a relatively high concentration of calcium in order to close and that a single action potential from just one trigger hair being touched does not reach this level. Therefore, a second hair needs to be stimulated to push the calcium concentration over this threshold and spring the trap. The encoding of the information is in the initial rise in calcium levels. The retention of the information requires maintaining a high enough level of calcium so that a second increase (triggered by touching the second hair) pushes the total concentration of calcium over the threshold. As the calcium ion concentrations dissipate over time, if the second touch and potential don’t happen quickly, the final concentration after the second trigger won’t be high enough to close the trap, and the memory is lost….

“Here, then, lies the proposed mechanism of the short-term memory in the Venus flytrap. The first touch of a hair activates an electric potential that radiates from cell to cell. This electric charge is stored as an increase in ion concentrations for a short time until it dissipates within about twenty seconds. But if a second action potential reaches the midrib within this time, the cumulative charge and ion concentrations pass the threshold and the trap closes. If too much time elapses between action potentials, then the plant forgets the first one, and the trap stays open.

“This electric signal in the Venus flytrap (and the electric signals in other plants for that matter) are similar to the electric signals in neurons in humans and indeed all animals. The signal in both neurons and Dionaea leaves can be inhibited by drugs that block the ion channels which open in the membranes as the electric signal passes through the cell. When Volkov pretreated his plants with a chemical that inhibits potassium channels in human neurons, for example, the traps didn’t close when they were touched or when they received the electric charges.”

cool, huh?!

that’s from What a Plant Knows? A Field Guide to the Senses. if you’re looking for an easy but info-packed read to bring with you on your summer vacation, you could do a lot worse. i’m reading it right now (well, not right now) and it’s terrific! the book is by the author of The Daily Plant (heh) blog.

remember, too, that plants are altruistic as well (see here and here)! (^_^)

(note: comments do not require an email. my favorite plant!)

your ethnicity…

…they can work that out from your mtdna. with a fr*ckin’ 80-90% accuracy rate! awesome. (don’t ask me what a ‘support vector machine’ is, but it sounds awesome, too!)

it’s “coarse ethnicity” — for instance caucasian, asian, african, hispanic — but still:

Inferring ethnicity from mitochondrial DNA sequence

“Background: The assignment of DNA samples to coarse population groups can be a useful but difficult task. One such example is the inference of coarse ethnic groupings for forensic applications. Ethnicity plays an important role in forensic investigation and can be inferred with the help of genetic markers. Being maternally inherited, of high copy number, and robust persistence in degraded samples, mitochondrial DNA may be useful for inferring coarse ethnicity. In this study, we compare the performance of methods for inferring ethnicity from the sequence of the hypervariable region of the mitochondrial genome.

“Results: We present the results of comprehensive experiments conducted on datasets extracted from the mtDNA population database, showing that ethnicity inference based on support vector machines (SVM) achieves an overall accuracy of 80-90%, consistently outperforming nearest neighbor and discriminant analysis methods previously proposed in the literature. We also evaluate methods of handling missing data and characterize the most informative segments of the hypervariable region of the mitochondrial genome.

“Conclusions: Support vector machines can be used to infer coarse ethnicity from a small region of mitochondrial DNA sequence with surprisingly high accuracy. In the presence of missing data, utilizing only the regions common to the training sequences and a test sequence proves to be the best strategy. Given these results, SVM algorithms are likely to also be useful in other DNA sequence classification applications.”

(but don’t forget — race doesn’t exist. it’s juuuust a social construct….)

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