evolution
razib | January 24, 2010Changes in human diet driven by cultural evolution seem to be at the root of many relatively recently emerged patterns of genetic variation. In particular, lactase persistence and varied production of amylase are two well known cases. Both of these new evolutionary genetic developments are responses to the shift toward carbohydrates over the last 10,000 years as mainstays of caloric intake. Rice and wheat serve as the foundations of much of human civilization. It is notable that both China and India are divided into rice and wheat (or millet) belts, so essential are modes of agriculture in…
cagapakis | January 24, 2010Cooperation and altruism are widespread in biology, from molecules and genes working together in a cell, to bacterial communities that require coordinated behavior to survive in a tough environment, to human relationships and societies. Our human cultural perspective (perhaps even more specifically our American cultural perspective, focused as it is on individuality, free markets, and the American Dream), however, treats cooperation as an outright anomaly that has to be explained away by science (or often, religion). If natural selection is about the "survival of the fittest" how can a…
grrlscientist | January 24, 2010tags: Birdbooker Report, bird books, animal books, natural history books, ecology books
"How does one distinguish a truly civilized nation from an aggregation of
barbarians? That is easy. A civilized country produces much good bird
literature."
--Edgar Kincaid
The Birdbooker Report is a special weekly report of a wide variety of science, nature and behavior books that currently are, or soon will be available for purchase. This report is written by one of my Seattle birding pals and book collector, Ian "Birdbooker" Paulsen, and is edited by me and published here for your information and…
emjohnson | January 23, 2010
Sapolsky's talk begins at 5:00 after an introduction by the Stanford Provost.
The neuroendocrinologist and primatologist Robert Sapolsky has been one of my primary scientific influences and the reason I pursued my masters and PhD in primate behavior and evolution. Not only is he a brilliant researcher and writer, he's also a genuinely kind and supportive guy. Back in 2001, as an undergraduate, I wrote what was then my first fan letter to a neuroscientist. To my surprise he wrote back and we had an ongoing correspondence. He even recommended a piece of writing I had sent him to his editor…
grrlscientist | January 22, 2010tags: evolution, evolutionary biology, evolutionary ecology, plumage color,carotenoid-based colour, carotenoids, lipid peroxidation, oxidative stress, sperm motility, sperm quality, sperm velocity, birds, ornithology, Great Tit, Parus major, researchblogging.org,peer-reviewed research, peer-reviewed paper
Great Tit, Parus major.
Image: Luc Viatour, Creative Commons/Wikipedia [larger view]
In some species of birds, males are more brightly colored than females. This phenomenon is due to female choice: females choose to mate with males that have the brightest plumage colors and most…
awild | January 21, 2010
Amblyopone australis: a primitive ant?
Earlier I chastised Christian Peeters and Mathieu Molet for misinterpreting the term "basal" in a phylogenetic context. What was that about?
The issue relates to the classic fallacy of viewing evolution as a linear progression from primitive to advanced. Popular conceptions of evolution aside, the process is not linear like a ladder so much as branching like a bush.
I don't know what quirk of human psychology so strongly predisposes us to frame ideas in linear narratives, but the fact that we do so makes evolution an unfortunately difficult concept…
edyong | January 21, 2010
The partnerships between flowering plants and the animals that pollinate them are some of the most familiar in the natural world. The active nature of animals typically casts the plants as the passive partners in this alliance, but in reality, they're just as involved. That becomes particularly apparent when the animals renege on their partnership.
Nicotinia attenuata, a type of wild US tobacco, is usually pollinated by hawkmoths. To lure them in, it opens its flowers at night and releases alluring chemicals. But pollinating hawkmoths often lay their eggs on the plants they visit and the…
razib | January 21, 2010Creation, the Charles Darwin biopic, is opening in a few large cities tomorrow.
razib | January 20, 2010Sometimes scientists report on research which clarifies what we already know. 'Survival of the Cutest' Proves Darwin Right:
The study, published in The American Naturalist on January 20, 2010, compared the skull shapes of domestic dogs with those of different species across the order Carnivora, to which dogs belong along with cats, bears, weasels, civets and even seals and walruses.
It found that the skull shapes of domestic dogs varied as much as those of the whole order. It also showed that the extremes of diversity were farther apart in domestic dogs than in the rest of the order. This…
awild | January 20, 2010Let me preface this post by saying that Christian Peeters is one of my absolute favorite myrmecologists. If lost in a remote African jungle and stalked by ravenous leopards, for example, Christian is the first ant guy I'd pick to help get me out of the predicament.
Having said that, this paper in Insectes Sociaux is so bad I nearly gouged my eyes out and ran around in little circles screaming and flailing my arms.
Nonetheless there exist extant ants with relatively simple societies, where size-polymorphic workers and large queens are absent. Recent phylogenies show that the poneroid…
grrlscientist | January 19, 2010tags: neurobiology, The Neurons that Shaped Civilization, mirror neurons, Ghandi neurons, social behavior, Lamarkian evolution, Darwinian evolution, VS Ramachandran, TEDTalks, streaming video
Neuroscientist Vilayanur Ramachandran outlines the fascinating functions of mirror neurons. Only recently discovered, these neurons allow us to learn complex social behaviors, some of which formed the foundations of human civilization as we know it.
TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of…
laelaps | January 19, 2010
The restored lower jaw of Arcanotherium (formerly Numidotherium savagei). (From Delmer, 2009)
Unlike the folks at this past weekend's ScienceOnline 2010 meeting, fossils don't come with nametags. The identification of preserved bits of ancient life relies upon careful comparison with what is already known, a task made all the more difficult for vertebrate paleontologists by the fragmentary nature of many of their subjects. Scraps of bone given one name could turn out to be parts of another partial skeleton given another name, or other bits of bone attributed one name could turn out to be…
milhayser | January 19, 2010
Evolutionary change responds to all kinds of pressures, and sometimes, the results can be surprising. On Gene Expression, Razib Khan challenges the idea that human evolution has stopped since "the vast majority of humans reach the age of potential reproduction." He explains that differential mortality is not a precondition for natural selection, and supports his claim with data on human height and reproduction. In a separate post, Razib considers the feral dogs of Moscow, a pack of 35,000 with unique characteristics, such as the savvy to ride the subway. On Living the Scientific Life,…
razib | January 17, 2010One of the things about evolution you sometimes hear is that it has "stopped" for humans. Steve Jones, a British geneticist, is one of the more prominent public expositors of this viewpoint today. The key fact that most people latch on to is that infant and child mortality is very low, so the vast majority of humans reach the age of potential reproduction. Random genetic drift aside, evolution via natural selection does not necessarily need differential mortality as a necessary precondition (though this is obviously an efficacious mechanism from the viewpoint of evolution). All that needs to…
razib | January 17, 2010A friend pointed me to this fascinating article about stray dogs in Moscow:
... It has become a symbol for the 35,000 stray dogs that roam Russia's capital - about 84 dogs per square mile. You see them everywhere. They lie around in the courtyards of apartment complexes, wander near markets and kiosks, and sleep inside metro stations and pedestrian passageways. You can hear them barking and howling at night. And the strays on Moscow's streets do not look anything like the purebreds preferred by status-conscious Muscovites. They look like a breed apart.
...
They also acted differently. Every…
grrlscientist | January 17, 2010tags: Birdbooker Report, bird books, animal books, natural history books, ecology books
"How does one distinguish a truly civilized nation from an aggregation of
barbarians? That is easy. A civilized country produces much good bird
literature."
--Edgar Kincaid
The Birdbooker Report is a special weekly report of a wide variety of science, nature and behavior books that currently are, or soon will be available for purchase. This report is written by one of my Seattle birding pals and book collector, Ian "Birdbooker" Paulsen, and is edited by me and published here for your information and…
grrlscientist | January 15, 2010tags: evolutionary biology, behavioral ecology, life history, migration, long-distance migration,birds,ornithology,researchblogging.org,peer-reviewed research, peer-reviewed paper
White-rumped sandpiper, Calidris fuscicollis, chicks on Bylot Island, Nunavut, Canada.
Image: Laura McKinnon [larger view]
I recently told you about research that used new microtechnology to document the incredible journey of Arctic Terns, a small bird species that annually migrates from its wintering area in Antarctica to its breeding colonies in Arctic and sub-Arctic regions of Europe, Asia, and North America…
razib | January 13, 2010The changing height of Homo erectus:
Today, I think it's fair to say that the variation of stature in Homo erectus was more or less like the variation within living people. There are short and tall populations today, varied in ecology and latitude. The average stature of young men in the Netherlands today is 184 cm. Adult women in the Philippines average only 150 cm. So the best way to compare statures is to illustrate the range.
That being said, I don't think we know how stature has evolved over time. We do have some data points -- the Neandertals were shorter than Upper Paleolithic…
cagapakis | January 13, 2010There have been a lot of great Darwin themed things popping up in the past few months in celebration of the 150th anniversary of On the Origin of Species, but none as avant garde and awesome as "Tomorrow, in a year", an electro-opera based on the life and work of Charles Darwin by The Knife, a Swedish electronic music duo (and one of my favorite bands). From the website of the company performing the opera, Danish theater group Hotel Pro Forma:
An opera singer, a pop singer and an actor perform The Knife's music and represent Darwin, time and nature on stage. Six dancers form the raw material…
edyong | January 13, 2010
Men who think that size really matters should probably not think too hard about the Y chromosome. This bundle of genes is the ultimate determinant of manliness, and it happens to be a degenerate runt. Over a few hundred million years, it has shrunk considerably, jettisoning around 97% of its original genes. Where it was once a large library of genes, now it's more a struggling independent bookstore. This loss of information defined the youth of the Y chromosome but nowadays, things are different. Renovation is the order of the day.
Jennifer Hughes from MIT revealed the recent history of…