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Evolutionary Biology, Life Science, Science Education, Human Evolution, and Stuff.
Greg Laden
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by Greg Laden in Greg Laden's Blog
In order to do good climate science, you have to understand and control for the sources of variation in the system. In any system that involvs metric change over time, there are four sources of variation: Read the rest of this post... | Read the comments on this post...... Read more »
Trenberth, K., Fasullo, J., & Abraham, J. (2011) Issues in Establishing Climate Sensitivity in Recent Studies. Remote Sensing, 3(9), 2051-2056. DOI: 10.3390/rs3092051
by Greg Laden in Greg Laden's Blog
I have never actually seen a snake eat a crocodile or a crocodile eat a snake, but I am pretty sure I've seen a snake planning to eat a Nile Croc. And that was in the geological present.
In the geological past, about 60 million years ago (during the "Eocene" a.k.a. "dawn age") there was a rain forest that is sort of the ancestor to modern rain forests, which is now a coal deposit (and thus, eventually, will be part of our air) in Columbia. It has yielded interesting materials, and the latest report, just published, is of a fossil dyrosaurid crocodyliform (ancient croc ancestor). It is African. Read the rest of this post... | Read the comments on this post...... Read more »
Hastings, A.K., Bloch, J. I., & Jaramillo, C.A. (2011) A new longirostrine dyrosaurid (Crocodylomorpha, Mesoeucrocodylia) from the Paleocene of north-eastern Colombia: biogeographic and behavioural implications for New-World Dyrosauridae . Palaeontology, 54(5), 1095-1116. info:/10.1111/j.1475-4983.2011.01092.x
by Greg Laden in Greg Laden's Blog
I think I know why science does not understand the female orgasm. It is because science excels when it breaks free of context, history, human complexities and anthropology, but when a topic requires one to grasp context, history, human complexities and anthropology, then science, especially the hard sciences, can fall short. Also, the nature of the female orgasm is a comparative question, but human sexuality is highly (but not entirely) derived; It is difficult to make a sensible graph or table comparing aspects of sexuality across mammals that usefully includes humans. It is not as impossible as making such a graph or table with "language" (which is entirely unique to humans) but still, it is difficult.
There is another problem as well. Female orgasm is actually a lot like male orgasm, and probably serves the same evolutionary role with one small but important difference. But, that one small but important difference, the ejaculation of seminal fluid by males, blinds researchers to any other function of male orgasms. Seminal fluid is distracting. Male ejaculation and female ovulation are rough homologues, but entirely different in their physiology and timing. Were it the case that female ovulation could only happen together with orgasm ... well, the human world would be a very different place but at least science would not be fumbling around in search of an answer for this enigma.
The reason I bring any of this up is because of a paper1, just published, that makes the claim that the "byproduct" theory of female orgasms is unsupported. So, I'd like to take a moment to explain the byproduct theory, to explain why this paper does not really address it let alone refute it, and then we'll get back to the question of what female orgasms really are for. The byproduct theory will not survive this discussion.
The byproduct theory originates with the following observations: Read the rest of this post... | Read the comments on this post...... Read more »
Zietsch, B., & Santtila, P. (2011) Genetic analysis of orgasmic function in twins and siblings does not support the by-product theory of female orgasm. Animal Behaviour. DOI: 10.1016/j.anbehav.2011.08.002
by Greg Laden in Greg Laden's Blog
The question of whether clouds are the cause of global warming has been settled:
No, they are not. Read the rest of this post... | Read the comments on this post...... Read more »
Dessler, A. (2011) Cloud variations and the Earth's energy budget. Geophysical Research Letters. DOI: 10.1029/2011GL049236
by Greg Laden in Greg Laden's Blog
A small "Signal-to-Noise Ratio" means that there is not enough real information (signal) compared to the background noise to make a definitive statement about something. With a sufficiently high Signal-to-Noise Ratio, it is possible to make statistically valid statements about some measure or observation. This applies to a lot of day to day decisions you make in life.
Climate change denialists understand this principle and they use it to try to fool people into thinking that "the jury is still out" on Global Warming, or that scientists are making up their data, and so on. Here, I want to explain very clearly what a Signal-to-Noise Ratio is and now it works in a totally understandable way; What this means for understanding Global Climate Change (in particular, warming); and to point you to an excellent paper ("Separating Signal and Noise in Atmospheric Temperature Changes: The Importance of Timescale") about to be published by Ben Santer and several other authors. Sander's paper effectively puts an end to Climate Change denialists misuse of data which has come to be known as "cherry picking" but that I prefer to call "dishonesty." Read the rest of this post... | Read the comments on this post...... Read more »
Santer, B., Karl, T., Lanzante, J., Meehl, G., Stott, P., Taylor, K., Thorne, P., Wehner, M., Wentz, F., Mears, C.... (2011) Separating Signal and Noise in Atmospheric Temperature Changes: The Importance of Timescale. Journal of Geophysical Research. DOI: 10.1029/2011JD016263
by Greg Laden in Greg Laden's Blog
There has been a major dust-up in the climate denialist world. A study published in late July made false claims and was methodologically flawed, but still managed to get published in a peer reviewed journal. The Editor-in-Chief of that journal has resigned to symbolically take responsibility for the journal's egregious error of publishing what is essentially a fake scientific paper, and to "protest against how the authors [and others] have much exaggerated the paper's conclusions" taking to task the University of Alabama's press office, Forbes, Fox News and others.
Let me break it down for you Read the rest of this post... | Read the comments on this post...... Read more »
Spencer, R., & Braswell, W. (2011) On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth’s Radiant Energy Balance. Remote Sensing, 3(8), 1603-1613. DOI: 10.3390/rs3081603
by Greg Laden in Greg Laden's Blog
The Honshu tsunami of March 11th (the one that caused the Fukushima disaster) caused the otherwise stable Sulzberger Ice Shelf to calve giant hunks of ice. Climate scientists call this "teleconnection." I call it a big whopping bunch of whack knocking off a gigunda chunka stuff. Either way, this is important and interesting. Read the rest of this post... | Read the comments on this post...... Read more »
Brunt, Kelly M., Okal, Emile A., & MacAyeal, Douglas. (2011) Antarctic ice-shelf calving triggered by the Honshu (Japan) earthquake and tsunami, March 2011 . Journal of Geology, 57(205), 785-788. info:/
by Greg Laden in Greg Laden's Blog
According to a newly published paper in the journal "Remote Sensing" the Earth's atmosphere releases into space more heat than climate scientists had previously estimated in a way that effectively removes concern about fossil CO2 being released into the atmosphere. Read the rest of this post... | Read the comments on this post...... Read more »
Spencer, R., & Braswell, W. (2011) On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth’s Radiant Energy Balance. Remote Sensing, 3(8), 1603-1613. DOI: 10.3390/rs3081603
by Greg Laden in Greg Laden's Blog
A proposal has been made to remove beloved Archaeopteryx from the bird family tree and push it over to some non-avian dinosaur subtree. This is not the first time that the ancient species has had its position on the tree of bird life threatened, but this time it may be for real. The proposal is reasonable.
Read the rest of this post... | Read the comments on this post...... Read more »
Xu, X., You, H., Du, K., & Han, F. (2011) An Archaeopteryx-like theropod from China and the origin of Avialae. Nature, 475(7357), 465-470. DOI: 10.1038/nature10288
by Greg Laden in Greg Laden's Blog
With Julia spending the summer and most of the fall in The Republic of Georgia, I've been thinking about various political and historical aspects of that country, and one of the things that is claimed to be true is that wine was first invented there. Recently, someone asked me (always ask the archaeologist esoteric stuff like this) where wine was first invented. And, recently, we scored some Concord Grapes, which are native to North America (presumably thanks to some bird a long time ago) as opposed to most grapes, and which provide the roots for most (nearly all?) wine grape stock. And, a paper on the genetics of wine came out recently and has been staring at me for a few weeks now. All these things together made me want to update my current knowledge of the origin of wine. Read the rest of this post... | Read the comments on this post...... Read more »
Myles, Sean, Boyko, Adam, Owens, Christopher, Brown, Patrick, Grassi, Fabrizio, Aradhya, Mallikarjuna, Prins, Bernard, Reynolds,Andy, Chia, Jer-Ming, Ware, Doreen.... (2011) Genetic structure and domestication history of the grape. PNAS. info:/
by Greg Laden in Greg Laden's Blog
It has been said that our most distant primate ancestors, the mammal that gave rise to early primates but itself wasn't quite a primate, was most like the Asian tree shrew, which is neither a shrew nor does it live in trees. This is, of course, untrue. When the average American sees a shrew native to the new world scurrying past, he or she usually thinks of it as a form of mouse. Which it isn't. (In fact, there are no "mice" native to the new world, but even if we give our hypothetical observer the concept of "rodent" as in "eeek, a rodent" the shrew is not that either.) If you spend any time hanging out with the Efe Pygmies of the Ituri Forest, eventually there will be a sudden movement on the forest floor, a quick snap of a machete or other similar implement, and ... elephant shrew will be on the menu. And, most interesting, all three of the aforementioned shrews do not belong comfortably together in a single taxonomic group. The closest non-shrew relative to the most common North American shrew are moles, the closest non-shrew relative to the Asian tree shrew are flying lemurs, bunnies, primates, and rodents; and the closest non-shrew relative to the African elephant shrew could be, astonishingly, an actual elephant! (Or hyraxes, goldem moles, sea cows or the Aardvark.) Read the rest of this post... | Read the comments on this post...... Read more »
BUCHLER, E. (1976) The use of echolocation by the wandering shrew (Sorex vagrans). Animal Behaviour, 24(4), 858-873. DOI: 10.1016/S0003-3472(76)80016-4
by Greg Laden in Greg Laden's Blog
Butter Milk Creek is a Texas archaeological site and an archaeological complex located rather symbolically a couple of hundred miles downstream from the famous Clovis site in New Mexico. It is the most recently reported alleged manifestation of a "pre-Clovis" archaeological presence. The most important thing about this site is probably this: It is well dated (though the dates need to be independently verified or otherwise run through the gauntlet of criticism dates of important sites are always subjected to) and there are a lot of artifacts at the site. The importance of the number of artifacts is two-fold: It means that the site is unambiguously evidence of human activities and not of the activities of, say, a ground squirrel burrow into which a random artifact from a later time fell, and it means that researchers will be able to say something interesting about the lithic (stone tool) technology represented there.
In order to understand why a "pre-Clovis" site is interesting, one needs to understand the peculiar nature of American archaeology and its conceptions of prehistory. Read the rest of this post... | Read the comments on this post...... Read more »
Waters, M., Forman, S., Jennings, T., Nordt, L., Driese, S., Feinberg, J., Keene, J., Halligan, J., Lindquist, A., Pierson, J.... (2011) The Buttermilk Creek Complex and the Origins of Clovis at the Debra L. Friedkin Site, Texas. Science, 331(6024), 1599-1603. DOI: 10.1126/science.1201855
by Greg Laden in Greg Laden's Blog
Siblings of those diagnosed with autism are more than 20 times as likely as members of the general population to also have autism. Some of these siblings also show evidence of autism-like but less marked cognitive and social communication problems. This suggests that autism has either an environmental cause typically found in all siblings during development or childhood or a strong heritable component, but there is not a known genetic link or a well established biological marker. A biological marker other than observed behavioral deficits would be a neurological phenotype such as might be seen in brain imaging.
Spencer et al, working from various units of Cambridge University seem to have identified such a marker. Read the rest of this post... | Read the comments on this post...... Read more »
Spencer, M., Holt, R., Chura, L., Suckling, J., Calder, A., Bullmore, E., & Baron-Cohen, S. (2011) A novel functional brain imaging endophenotype of autism: the neural response to facial expression of emotion. Translational Psychiatry, 1(7). DOI: 10.1038/tp.2011.18
by Greg Laden in Greg Laden's Blog
Humans appear to have a reasonable amount of diversity in their sexual orientations, in what is often referred to as "gender" and in adult behavior generally. When convenient, people will point to "genes" as the "cause" of any particular subset of th is diversity (or all of it). When convenient, people will point to "culture" as the "cause" of ... whatever. The "real" story is more complicated, less clear, and very interesting. And, starting now, I promise to stop using so many "scare" quotes. Read the rest of this post... | Read the comments on this post...... Read more »
Moore, C., & Morelli, G. (1979) Mother rats interact differently with male amd female offspring. Journal of Comparative and Physiological Psychology, 93(4), 677-684. DOI: 10.1037/h0077599
by Greg Laden in Greg Laden's Blog
There are several things that cause extinction, but ultimately it is always the same: The last individual (or small number of individuals) of a species die. That may sound like a trivial explanation for extinction but consider what happens when you work backwards from that tragic moment in time. Well, you have more individuals in a population that was once much larger but was reduced in size somehow, which then dwindled to the last few, the last one, then zero. But how did that small population go from hundreds to a few then to zero? Most likely for no particular reason other than this: The number of individuals in a population can be made to vary in roughly absolute terms, as well as relative terms. Say there is a population of a rare rabbit, Bugs bunnii living in a region the size of Yellowstone National Park. If you introduce 1,000 coyotes to this area, they will eat rabbits indiscriminately, all species, and along the way they may consume almost all of the B. bunnii leaving maybe three or four. Then, those wemaining wabbits die off because they are all males, or for some other totally dumb and tragic reason. Read the rest of this post... | Read the comments on this post...... Read more »
He, F., & Hubbell, S. (2011) Species–area relationships always overestimate extinction rates from habitat loss. Nature, 473(7347), 368-371. DOI: 10.1038/nature09985
by Greg Laden in Greg Laden's Blog
It seems like every time I take Huxley (now 18 months old) to the doctor, the following things happen: 1) Somebody says "Well, he won't need to get stuck with any needles for a long while now .... his next scheduled immunization is [insert phrase indicating 'a long time into the future']"; and 2) Huxley gets stuck with some needles.
The last time, a few days ago, was especially bad. Read the rest of this post... | Read the comments on this post...... Read more »
Chen, S., Anderson, S., Kutty, P., Lugo, F., McDonald, M., Rota, P., Ortega-Sanchez, I., Komatsu, K., Armstrong, G., Sunenshine, R.... (2011) Health Care-Associated Measles Outbreak in the United States After an Importation: Challenges and Economic Impact. Journal of Infectious Diseases. DOI: 10.1093/infdis/jir115
by Greg Laden in Greg Laden's Blog
Europa is a moon of Jupiter, the smallest of the four Jovian moons discovered by Galileo in 1610. Juipter has 63 objects circling it that are called moons, though only eight of them are "regular" in their orbit and other characteristics. The rest are bits and pieces of clumped up matter that were probably captured by Jupiter's big-ass gravitational field, and have irregular orbits, i.e., they go the wrong-way around the planet, or are not in the solar plane, etc. Read the rest of this post... | Read the comments on this post...... Read more »
Greenberg, R. (2011) Exploration and Protection of Europa's Biosphere: Implications of Permeable Ice. Astrobiology, 11(2), 183-191. DOI: 10.1089/ast.2011.0608
by Greg Laden in Greg Laden's Blog
Not long after Yellowstone Park was officially created, a small group of campers were killed by Nez Pers Indians on the run from US troops1. More recently, the last time I was in the area, a ranger was killed by a Grizzly Bear (so was his horse) on the edge of the park. A quick glance at my sister's newspaper archives (Lightning Fingers Liz a.k.a. Caldera Girl has been running newspapers in the region for nearly forty years) shows a distinctive pattern of danger in the Caldera, mainly in relation to the lack of turning lanes on highways with poor visibility and other traffic related hazards.
So, no, the Yellowstone Caldera is not especially safe, what with cars, humans, and griz everywhere. Oh, and every now and then somebody falls into a geyser. But you are probably here because you are interested in a different question: Is the Yellowstone Caldera, the volcanic feature, not the natural and cultural landscape, dangerous? In other words, is one of the largest volcanoes to exist on the earth ever gonna blow? Like this?
(Photograph from UFO Digest)
Read the rest of this post... | Read the comments on this post...... Read more »
Chang, W., Smith, R., Farrell, J., & Puskas, C. (2010) An extraordinary episode of Yellowstone caldera uplift, 2004–2010, from GPS and InSAR observations. Geophysical Research Letters, 37(23). DOI: 10.1029/2010GL045451
by Greg Laden in Greg Laden's Blog
A Better Grip: T Cells Strengthen Our Hand against Influenza Clinical Infectious Diseases, 52 (1), 8-9 DOI: 10.1093/cid/ciq018Flu vaccines are important and useful, but also relatively ineffective compared to many other vaccines. Immunity is imperfect, there are many 'strains' of influenza in a given year only some of which are addressed by the available vaccine (though often the most common ones) and one year's vaccine does not provide immunity to subsequent years' influenza because the virus changes so much. Well, actually that's not exactly true: The influenza virus has various different parts, and the parts that the traditional flu vaccine uses to induce an antigenic reaction in the potential hose is highly variable. Other parts of the flu vaccine are not as variable. If only a vaccine could be developed that uses the less variable part of the influenza virus, then perhaps it would be a universal, long-lasting vaccine that you take once, and become pretty much immune to all future influenza. Read the rest of this post... | Read the comments on this post...... Read more »
Berthoud, T., Hamill, M., Lillie, P., Hwenda, L., Collins, K., Ewer, K., Milicic, A., Poyntz, H., Lambe, T., Fletcher, H.... (2011) Potent CD8 T-Cell Immunogenicity in Humans of a Novel Heterosubtypic Influenza A Vaccine, MVA-NP M1. Clinical Infectious Diseases, 52(1), 1-7. DOI: 10.1093/cid/ciq015
Hambleton, S. (2011) A Better Grip: T Cells Strengthen Our Hand against Influenza. Clinical Infectious Diseases, 52(1), 8-9. DOI: 10.1093/cid/ciq018
by Greg Laden in Greg Laden's Blog
This came up a while ago and I assumed the idea would die the usual quick and painless death, but the idea seems to be either so fascinating or so irritating to people (mainly in various blog comment sections) that it still twitches and still has a heartbeat, but only as a result of the repeated flogging it is getting.
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Gelstein, S., Yeshurun, Y., Rozenkrantz, L., Shushan, S., Frumin, I., Roth, Y., & Sobel, N. (2011) Human Tears Contain a Chemosignal. Science, 331(6014), 226-230. DOI: 10.1126/science.1198331
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