linkfest – 07/22/12

a day late. sorry ’bout that!

Has Ron Unz Refuted “Hard Hereditarianism”? – nope. @vdare.

J. Philippe Rushton Says Color May Be More Than Skin Deep – also @vdare. see also Do pigmentation and the melanocortin system modulate aggression and sexuality in humans as they do in other animals? [opens pdf]

Neanderthals ate their greens“Tooth analysis shows that european hominins roasted vegetables and may have used medicinal plants.”

Cross-national correlates of corruption – from the inductivist.

Bounty mutineer descendants may hold key to myopia“Descendants of the famous Bounty mutineers who now live on an isolated Pacific Island have among the lowest rate of myopia in the world and may hold the key to unlocking the genetic code for the disease.”

bonus: History Resumes: Sectarianism’s Unlearned Lessons“[A]s Valli Nasr observed in an influential postmortem essay he wrote for Foreign Affairs in 2006, ‘The Bush administration thought of politics as the relationship between individuals and the state, and so it failed to recognize that people in the Middle East see politics also as the balance of power among communities.'”

bonus bonus: Evolution in a Jiffy

bonus bonus bonus: Newfound Monkey Flower Reveals Evolution in Action“A new species of monkey flower has been found in Scotland, the product of a tryst between two foreign flowers. But this is no ordinary love child. While almost all such hybrids are sterile — just as mules are sterile hybrids of donkeys and horses — a rare genetic duplication allowed this species to become fertile.”

bonus bonus bonus bonus: Medieval lingerie – fifteenth century “tuttensecks.”

bonus bonus bonus bonus bonus: Who Needs the Euro When You Can Pay With Deutsche Marks?“Germans hang on to old currency….”

bonus bonus bonus bonus bonus bonus: The Graph Of Ideas – graphing every idea in history. don’t miss: Philosophers of antiquity influencing 18th, 19th and 20th century philosophers.

edit: Preliminary notes on the possible sociobiological implications of the rural Chinese political economy [opens pdf]

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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!)

linkfest – 06/10/12

Consanguinity and Corruption“Computing simple, unweighted averages for each country for which studies and surveys have been conducted and subsequently recorded on consang.net and then comparing them to Transparency International’s 2011 Corruptions Perception Index yields a correlation of .44 (p = 0).” – from the awesome epigone! see also steve sailer.

Does cooperation require both reciprocity and alike neighbours? – the answer is yes: “The researchers conclude that human societies can best achieve high levels of cooperative behaviour if their individuals interact repeatedly, and if populations exhibit at least a minor degree of structure.” – in other words, if the members of a society are related to some degree.

Re-Examining the “Out of Africa” Theory and the Origin of Europeoids (Caucasoids) in Light of DNA Genealogyopen access [pdf].

An Asian Origin for Human Ancestors?“Researchers agree that our immediate ancestors, the upright walking apes, arose in Africa. But the discovery of a new primate that lived about 37 million years ago in the ancient swamplands of Myanmar bolsters the idea that the deep primate family tree that gave rise to humans is rooted in Asia. If true, the discovery suggests that the ancestors of all monkeys, apes, and humans—known as the anthropoids—arose in Asia and made the arduous journey to the island continent of Africa almost 40 million years ago.”

Exercise benefits black girls less than whites, study shows“Physical activity seems a nearly sure way to prevent obesity in white adolescent girls, but does not have the same effect on African American girls, researchers say…. The study … falls in line with research that finds black women oxidize fat more slowly in response to exercise, and that their resting metabolic rates are lower than those of white women.”

[White] Americans’ heads have been growing, scientists say“Over the last 150 years or so, it appears that skulls got narrower from side to side by about 5 to 7 millimeters, and higher from top to bottom by an average of nearly 10 millimeters, Jantz said. And the overall size of the head has, on average, increased by an amount equivalent to the size of a tennis ball, he said.”

Menstrual huts protect Dogon men from cuckoldry“Women who practise the traditional Dogon religion, unlike those who are Muslim or Christian, spend five days a month around the time of menstruation in a highly visible ‘menstrual hut’. Strassmann tested paternity in 1700 Dogon father and son pairs and found that those who practised the traditional religion were four times less likely to be raising someone else’s son than those who practised Christianity.”

Lady Liaisons: Does Cheating Give Females an Evolutionary Advantage?“‘This is one of the most careful and most robust studies to explore whether polyandry is adaptive in females,’ says Tommaso Pizzari, a University of Oxford biologist who was not involved in the research. ‘The answer is: not really.'” – at least not in canadian song sparrows.

bonus: Plants may be able to ‘hear’ others

bonus bonus: Parasitic plants ‘steal’ genes from their hosts

bonus bonus bonus: Skeletons treated for vampirism found in Bulgaria – vampires!

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linkfest – 03/04/12

European Neanderthals Were On the Verge of Extinction Even Before the Arrival of Modern Humans“New findings from an international team of researchers show that most Neanderthals in Europe died off around 50,000 years ago.”

New evidence suggests Stone Age hunters from Europe discovered America“New archaeological evidence suggests that America was first discovered by Stone Age people from Europe – 10,000 years before the Siberian-originating ancestors of the American Indians set foot in the New World.” – who was here first? see also: Radical theory of first Americans places Stone Age Europeans in Delmarva 20,000 years ago

Firing My Own Bu-cannon – good one from john derbyshire!

Wealthy More Likely to Lie, Cheat: Researchers – tell us something we don’t know. (~_^)

Different bodies, different minds“[P]eople tend to prefer the things that they encounter on the same side as their dominant hand.”

Experts ‘taste wine differently from others’“A study has found that specialist oenophiles have a much more acute sense of taste than the rest of us – and it may even be in the genes.” – the wine experts found propylthiouracil to be really bitter.

Are Emotions Prophetic? – the “emotional oracle effect.”

The Greater Your Fear, the Larger the Spider“People who are afraid of spiders see the arachnids as bigger than they actually are, recent experiments have shown.” – or maybe they’re more afraid of spiders because they perceive them as larger?

Nearby chimpanzee populations show much greater genetic diversity than distant human populations“Surprisingly, even though all the chimpanzee populations lived in relatively close proximity, with the habitats of two groups separated only by a river, chimpanzees from different populations were substantially more different genetically than humans living on different continents.” – original paper: Genomic Tools for Evolution and Conservation in the Chimpanzee: Pan troglodytes ellioti Is a Genetically Distinct Population.

bonus: Plants have a memory of pests that spans generations – epigentic stuff!

(note: comments do not require an email. in vino veritas.)

linkfest – 02/26/12

In the genes, but which ones?“‘As is the case with other traits, like height, there are probably thousands of genes and their variants that are associated with intelligence…. And there may be other genetic effects beyond the single gene effects – there could be interactions between genes, there could be interactions between genes and the environment.'”

Drinking Alcohol Shrinks Critical Brain Regions in Genetically Vulnerable Mice“[D]opamine receptors, known as DRD2, may play a protective role against alcohol-induced brain damage.”

Racial differences in childhood myopia – from the inductivist.

Lactase Persistence and Understanding History – from henry harpending.

Rethinking the social structure of ancient Eurasian nomads: Current Anthropology research“[E]arly pastoral nomads grew distinct economies across the steppes and mountains of Eurasia and triggered the formation of some the earliest and most extensive networks of interaction in prehistory.”

The emoticon on your face“[R]esearchers are suggesting that happy and sad expressions are not basic, evolutionary responses that take the same form all over the world, but cultural categories that we create from a much more complex emotional reservoir.”

A Sip for the Ancestors: The True Story of Civilization’s Stumbling Debt to Beer and Fungus – great series! i recommend reading them all (links at the top of the article i linked to here). (^_^)

Zoologger: The bird that cares for its rival’s chicks

bonus: NASA Will Pay You to Eat Astronaut Food for 4 Months

bonus bonus: The Bruce effect – why some pregnant monkeys abort when new males arrive

bonus bonus bonus: Dead for 32,000 Years, an Arctic Plant Is Revived

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curioser and curioser

just when you think you’ve got inbreeding and genetics sorted out in your head (almost — well, no, not really), they throw something new at ya.

here’s an article that linton @nobabies.net pointed out to me (thanks, linton!):

“Epigenetics Linked to Inbreeding Depression”
16 September 2011

“Inbreeding depression is the bane of conservation biology. When closely related individuals mate, which can happen when there aren’t too many members of a species left, their offspring are often less fit and less fertile, making the species all the more vulnerable. Both plants and animals can suffer from inbreeding depression, and textbooks typically attribute this phenonmenon to genetics: Recessive genes with harmful effects, whose negative influences are normally masked by a dominant copy of a gene, are more likely to pair up in offspring of more genetically similar parents.

“Or so the theory goes.

“But Philippine Vergeer, an evolutionary ecologist at Radboud University Nijmegen in the Netherlands, suspects that epigenetics — chemical modifications to the DNA that alter gene activity — may also be to blame, at least in plants….

“Vergeer and her Radboud colleagues Niels Wagemaker and Joop Ouborg compared DNA methylation between outbred and inbred S. columbaria — also known as small scabious — derived from the same mother plant. Methylation was 10% higher in inbred plants…. Also, inbred and outbred plants have different parts of their genomes methylated.

“The scientists then decided to look at what happened to plant offspring if they reconfigured the flora’s methylation. Every day for a week, they exposed germinating seeds of inbred and outbred plants to a demethylating agent. The result: ‘Phenotypic differences between outbred and inbred plants are nullified,’ Vergeer reported….”

so, at least in the case of these little plants, inbreeding depression seems to be connected to epigenetics and not genetics. when they reversed the epigenetics in these plants, the inbred plants photosynthesized (which is what the researchers were measuring) just as well as the outbred plants.

neato!

there has been some research done showing that epigenetic states are probably regulated (if that’s the right way to put it) by the underlying genetics, so perhaps the inbreeding depression in these plants was still a result of too many “bad genes.” but it’s cool that they could reverse the inbreeding depression by getting rid of the methylation!

there have also been studies, of course, showing that some epigentic states can be inherited across a few or several generations.

see also: Inbreeding and epigenetics: beneficial as well as deleterious effects

previously: the genetics of epigenetics

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carrots

since even plants are more altruistic to other individual plants most closely related to themselves (i.e. more so to their brother and sister plants, i suppose, than to their cousins or to strangers), dropping down fewer roots when they are neighbors to close relatives, oughtn’t i then make sure to plant unrelated carrots next to one another in a row in order to maximize the root size? (not to mention my rutabaga, turnips, and parsnips!)

inclusive fitness — essential for even the home gardener to understand?

(^_^)

previously: even plants do it!

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