HENRY the Human Evolution News Relay

21Jan/09Off

The problems with Paleofantasies

Marlene Zuk in the New York Times attacks a core belief of Evolutionary Psychology:

Remember when life was simpler, and diets weren’t full of processed food and chemicals? No, not the 1950s. Increasingly, we are developing nostalgia for a much earlier epoch: the Pleistocene, when humans lived in small hunter-gatherer groups and didn’t worry about high cholesterol.

(...) In short, we have what the anthropologist Leslie Aiello called "paleofantasies."

16Jan/09Off

Victorian novels helped us evolve into better people, say psychologists

The despicable acts of Count Dracula, the unending selflessness of Dorothea in Middlemarch and Mr Darcy's personal transformation in Pride and Prejudice helped to uphold social order and encouraged altruistic genes to spread through Victorian society, according to an analysis by evolutionary psychologists.

Victorian novels helped us evolve into better people, say psychologists.. um, ok...

20Oct/07Off

Sunday pot-luck

Assorted interesting posts for nice lazy Sunday:

  1. John Hawks provides the best discussion of the recent identification of the FoxP2 gene in Neanderthals without any of the stupid journalistic hype that others have succumbed to (although he does use the term "neandercooties"). Go read his The amazing talking Neandertals.
  2. Creek Running North has identified that
    Evolutionary Psychology may be genetically hardwired
    ...

    Biologists have long assumed that evolutionary psychology, a controversial branch of psychology that ascribes many common social behaviors to genetics, is a muddled blend of half-understood evolutionary biology, selective data mining and resentment of women’s changing roles in society.

    A new study, published in today’s issue of the German publication Unwirklichen Genetikjournal, does not challenge that assessment. But it does suggest that some men may be genetically predisposed to believe in evolutionary psychology, a finding that may well suggest future methods of treatment of the psychological malady.

  3. Scientist debunks nomadic Aborigine 'myth':

    Before white settlers arrived, Australia's indigenous peoples lived in houses and villages, and used surprisingly sophisticated architecture and design methods to build their shelters, new research has found.

  4. More ammunition inn the punctuated evolution debate, this time it's Punctuated genome size evolution in Liliaceae:

    Most angiosperms possess small genomes (mode 1C = 0.6 pg, median 1C = 2.9 pg). Those with truly enormous genomes (i.e. ≥ 35 pg) are phylogenetically restricted to a few families and include Liliaceae – with species possessing some of the largest genomes so far reported for any plant as well as including species with much smaller genomes. To gain insights into when and where genome size expansion took place during the evolution of Liliaceae and the mode and tempo of this change, data for 78 species were superimposed onto a phylogenetic tree and analysed. Results suggest that genome size in Liliaceae followed a punctuated rather than gradual mode of evolution and that most of the diversification evolved recently rather than early in the evolution of the family.

  5. The Evolutionary Origins of Human Patience: Temporal Preferences in Chimpanzees, Bonobos, and Human Adults:

    To make adaptive choices, individuals must sometimes exhibit patience, forgoing immediate benefits to acquire more valuable future rewards. Although humans account for future consequences when making temporal decisions, many animal species wait only a few seconds for delayed benefits. Current research thus suggests a phylogenetic gap between patient humans and impulsive, present-oriented animals, a distinction with implications for our understanding of economic decision making and the origins of human cooperation.

    On the basis of a series of experimental results, we reject this conclusion. First, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes) exhibit a degree of patience not seen in other animals tested thus far. Second, humans are less willing to wait for food rewards than are chimpanzees. Third, humans are more willing to wait for monetary rewards than for food, and show the highest degree of patience only in response to decisions about money involving low opportunity costs.

    These findings suggest that core components of the capacity for future-oriented decisions evolved before the human lineage diverged from apes. Moreover, the different levels of patience that humans exhibit might be driven by fundamental differences in the mechanisms representing biological versus abstract rewards.

  6. Finally, there's a fun review and historical perspective of neutral theory in the latest Journal of Evolutionary biology:

    To resolve a panselectionist paradox, the population geneticist Kimura invented a neutral theory, where each gene is equally likely to enter the next generation whatever its allelic type. To learn what could be explained without invoking Darwinian adaptive divergence, Hubbell devised a similar neutral theory for forest ecology, assuming each tree is equally likely to reproduce whatever its species. In both theories, some predictions worked; neither theory proved universally true.

    Simple assumptions allow neutral theorists to treat many subjects still immune to more realistic theory. Ecologists exploit far fewer of these possibilities than population geneticists, focussing instead on species abundance distributions, where their predictions work best, but most closely match non-neutral predictions.

    Neutral theory cannot explain adaptive divergence or ecosystem function, which ecologists must understand. By addressing new topics and predicting changes in time, however, ecological neutral theory can provide probing null hypotheses and stimulate more realistic theory.

14Aug/07Off

Sexual Selection Has Shaped the Hominin Face

Weston et al in PLoS One show that sexual selection has shaped the Hominin face (doi:10.1371/journal.pone.0000710):

We consider sex differences in human facial morphology in the context of developmental change. We show that at puberty, the height of the upper face, between the lip and the brow, develops differently in males and females, and that these differences are not explicable in terms of sex differences in body size.

We find the same dimorphism in the faces of human ancestors. We propose that the relative shortening in men and lengthening in women of the anterior upper face at puberty is the mechanistic consequence of extreme maxillary rotation during ontogeny. A link between this developmental model and sexual dimorphism is made for the first time, and provides a new set of morphological criteria to sex human crania.

This finding has important implications for the role of sexual selection in the evolution of anthropoid faces and for theories of human facial attractiveness.

Their results suggest that facial attractiveness played a major role in human evolution.

24Jun/07Off

Yawning to cool your brain

Could yawning be an adaptation to cool the brain?

The next time you "catch a yawn" from someone across the room, you're not copying their sleepiness, you're participating in an ancient, hardwired ritual that might have evolved to help groups stay alert as a means of detecting danger.

The full paper is available at Evolutionary Psychology (PDF!):

We conducted two experiments that implicate yawning as a thermoregulatory mechanism. The first experiment demonstrates that different patterns of breathing influence susceptibility to contagious yawning. When participants were not directed how to breathe or were instructed to breathe orally (inhaling and exhaling through their mouth), the incidence of contagious yawning in response to seeing videotapes of people yawning was about 48%. When instructed to breathe nasally (inhaling and exhaling through their nose), no participants exhibited contagious yawning. In a second experiment, applying temperature packs to the forehead also influenced the incidence of contagious yawning.

When participants held a warm pack (460C) or a pack at room temperature to their forehead while watching people yawn, contagious yawning occurred 41% of the time. When participants held a cold pack (40C) to their forehead, contagious yawning dropped to 9%. These findings suggest that yawning has an adaptive/functional component that it is not merely the derivative of selection for other forms of behavior.

19May/07Off

How to write consistently boring scientific literature

Kai Sand-Jensen has a great paper in Oikos (of all places?) where he asks the great question why are scientific publications boring?, and comes up with ten recommendations how to write boring papers. I’ve taken his list and paraphrased them below:

1) Avoid Focus: Far too often the main results are hidden after paragraphs of densely layered questions, ideas and arguments. Please be clear and directly state your main hypothesis.

2) Avoid originality and personality: Please present your studies with originality and be excited about them! If they’re not exciting, why are you bothering to publish them?

3) Write l-o-n-g contributions – Short papers are good. Long papers may show off your deep understanding of the nuances of your topic, but you’ll be the only one reading it (Some fields are worse than others here – I won’t mention any names though!).

4) Remove implications and speculation: These are the fun bits of science. Removing them makes your paper pointless. Sand-Jensen appropriately quotes one of the most gorgeous lines in biology here:

It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material. (Watson & Crick 1953)

5) Leave out illustrations: Pictures are truly worth a thousand words. Besides, most of the time, they’re the only thing anyone looks at. I’d argue that there’s a corollary to this: you should leave out useless figures (cough median-joining networks cough). Only keep the ones that explain your study and results beautifully

6) Omit necessary steps of reasoning: This one hits home – I’ve been working on replicating an analysis done a year ago, but the details are just not available in the paper for me to work out what’s going on. A flowchart would have been wonderful.

7) Use many abbreviations and terms: Whilst this shows how learned you are, it immediately makes your paper inaccessible to anyone interested.

8 ) Suppress humor and flowery language: I can’t put this better than Kai Sand-Jensen did:

Naming a new species Cafeteria, or for that matter calling a delicate, transparent medusa Lizzia blondina, shows lack of respect and will prevent us from ever forgetting the names. I highly discourage creating these
kinds of clever names, because science writing should remain a puritanical, serious and reputable business.

9) Degrade Biology to Statistics: That is, do not “reduce all species to numbers or statistical elements without considering any interesting biological aspects of adaptation, behavior and evolution”. I may be guilty of this one myself preferring the big-picture approach, but I do try to remember why I find the topic interesting at all – and that’s got nothing to do with, oh, Bayes Factors.

10) Quote numerous papers for trivial statements: Not everything needs a reference, especially not the trivial points. I know you spent hours finding and reading those boring papers, but let it go…

In short: reading science should be fun, and writing science should be fun… and now I’m back to writing up a boring paper.

23Nov/06Off

No dark sociobiology in the classroom

David Barash attempts to write a Gould-style essay on how to teach sociobiology:

“Should we revise Pink Floyd’s anthem “Another Brick in the Wall” – with its chorus “No dark sarcasm in the classroom/Teachers leave them kids alone” – to “No dark sociobiology in the classroom”? To answer this, we need first to examine that purported darkness.”

…and fails rather hilariously

   
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