242 posts · 471,099 views
Evolutionary Biology, Life Science, Science Education, Human Evolution, and Stuff.
If all the water currently trapped in all the glaciers across the entire world, the sea level would rise far more than most people imagine. Almost everyone living anywhere in the world at an elevation of below about 500 feet with a direct drainage to the sea would be directly affected; The sea level rise itself might be a bit over 300 feet, but oceans tend to migrate horizontally when they rise onto previously uninnundated land surfaces. So if you lived at 500 feet above sea level in most of Maine, you'd have a much shorter walk to the rocky shoreline, but if you lived at 500 feet across much of the Gulf Coast it would only be a matter of time until the eroding sea cliff reached you incorporated you into the offshore sediments.
Having said that, Anthropogenic Global Warming has resulted in only modest sea level rise to date, and it is at this point probably true that warming of the ocean causing thermal expansion has been at the same level of magnitude (or greater) than seas rising because of the influx of melted glacial water.
The problem is, it is very difficult to measure either sea level rise or ice loss very accurately, for a number of reasons. But there is a saving grace. Or should I say, GRACE. GRACE is a NASA project; Twin satellites measure changes in the Earth's gravity field in such a way that it is possible to identify changes in the distribution of water. From the GRACE overview statement:
Read the rest of this post... | Read the comments on this post...... Read more »
Jacob, T., Wahr, J., Pfeffer, W., & Swenson, S. (2012) Recent contributions of glaciers and ice caps to sea level rise. Nature. DOI: 10.1038/nature10847
In a very interesting way.
As a regular reader of this blog, you know that IQ and similar measures are determined by a number of factors, and for most "normal" (modal?) individuals, one's heritage (genes) is rarely important. Putting it another way, variation across individuals in IQ and other measures have been shown again and again to be determined by things like home environment, diet and nutrition, and even immediate social context. Here's another finding supporting this: Read the rest of this post... | Read the comments on this post...... Read more »
Kishida, K., Yang, D., Quartz, K., Quartz, S., & Montague, P. (2012) Implicit signals in small group settings and their impact on the expression of cognitive capacity and associated brain responses. Philosophical Transactions of the Royal Society B: Biological Sciences, 367(1589), 704-716. DOI: 10.1098/rstb.2011.0267
Over the last few weeks I've run into a few misconceptions about tobacco, as well as some interesting news, so I thought I'd share. If you already know some of this, forgive me, not everyone else does.
First, tobacco, Nicotiana tabacum, is a member of the Solanaceae family of plants, which from a human perspective has got to be one of the most interesting plant families out there. It includes Belladonna, peppers, potatoes, and tomatoes. So, from this one family of plants, you can kill your neighbor, have a nice meal, and a smoke a cigar afterward. Read the rest of this post... | Read the comments on this post...... Read more »
Zagorevski, Dmitri, & Loughmiller-Newman, Jennifer. (2012) The Detection of Nicotine in a Late Mayan Period Flask by GCMS and LCMS Methods. Rapid Communications in Mass Spectrometry, 403-411. info:/
The sun heats the earth, but unevenly. The excess heat around the equator moves towards the poles, via a number of different mechanisms, the most noticeable for us humans being via air masses. That's what much of our weather is about. Heat also moves towards the poles, in the ongoing evening-out of energy distribution on the planet's surface, via ocean currents.
One of the interesting things that happens with ocean currents is this: Warm water tends to move from equator towards polar regions across the surface, then cools down and drops to the deep sea, where it moves back south again, often in a kind of loop that we call a "conveyor." Becuase of some quirky historical stuff, the continents on this planet are mostly in the norther hemisphere, so the loops of ocean water that mariners have long called "currents" are extra strange in the north, and as it happens, there is a big loop of warm water or two that go way farther north (as warm water) than usual, where increased evaporation and cooling cause the water to a) loose it's heat to the air and b) sink rather dramatically to the bottom of the sea. The sinking helps direct the north-moving surface currents, maintaining the loop. The release of heat keeps England from looking like Canada and Norway from looking like Greenland, as much of this heat leaves the North Atlantic and traverses Europe first. By the time that energy gets around the world all the way back to Greenland, well, it isn't helping to melt glaciers very much, bit it does in fact have an effect. Without this warming, there would probably be continental glacial masses on Europe and Canada, rather than scattered and small mountain glaciers. In other words, there would be an ice age.
Did I mention the evaporation as a driving force in the conveyor? Yes, of course I did. And the reason this works is that when the warm surface water evaporates, it becomes more saline relative to the rest of the ocean, and sinks, because salty water is denser than fresh water. We believe that there have been times in the past when fresh water being added to the northern seas has mixed with a conveyor, caused the water to be less salty, turned off the flow of warm water to the northerly latitudes, and ushered in a mini-ice age, or perhaps a maxi-ice age. Indeed, there are some theories about paleoclimate that suggest, very strongly, that this is exactly the mechanism that triggers an ice age. Read the rest of this post... | Read the comments on this post...... Read more »
In a recent study, 35,533 prostate cancer-free men in a higher risk age group for prostate cancer in the US, Canada and Puerto Rico were given various treatments of Vitamin E, selenium, and placebo in order to see if claims that Vitamin E and/or Vitamin E with selenium were effective in reducing prostate cancer risk.
8752 received selenium alone - 575 developed prostate cancer.
8737 received Vitamin E alone - 620 developed prostate cancer.
8702 received both - 555 developed prostate cancer.
8696 placebo - 529 developed prostate cancer.
It turns out that Vitamin E may increase the risk of prostate cancer. Using Vitamin E and/or Selenium to reduce risk of prostate cancer in men old enough to have a higher risk of this disease is ineffective.
Klein, E., Thompson, I., Tangen, C., Crowley, J., Lucia, M., Goodman, P., Minasian, L., Ford, L., Parnes, H., Gaziano, J., Karp, D., Lieber, M., Walther, P., Klotz, L., Parsons, J., Chin, J., Darke, A., Lippman, S., Goodman, G., Meyskens, F., & Baker, L. (2011). Vitamin E and the Risk of Prostate Cancer: The Selenium and Vitamin E Cancer Prevention Trial (SELECT) JAMA: The Journal of the American Medical Association, 306 (14), 1549-1556 DOI: 10.1001/jama.2011.1437
Read the comments on this post...... Read more »
Klein, E., Thompson, I., Tangen, C., Crowley, J., Lucia, M., Goodman, P., Minasian, L., Ford, L., Parnes, H., Gaziano, J.... (2011) Vitamin E and the Risk of Prostate Cancer: The Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA: The Journal of the American Medical Association, 306(14), 1549-1556. DOI: 10.1001/jama.2011.1437
Although one can not be certain, all the evidence points to the fact that William Shakespeare smoked pot. This is not a new story. My good friend and colleague, Dr. Francis Thackeray, who has never smoked pot in his life but who has acted in Shakespeare's plays numerous times, led a research team that put 2 and 2 together and came up with narcotic literary munchies. In Shakespeare's time, land owners were required to grow pot in order to provide fibers for making the rope needed hoist the sails and flags over the increasingly powerful British Navy and merchant vessels. One of the better depictions of Shakespeare's face shows the well known smoker's mark, a feature that forms when one habitually smokes with a kaolin tobacco pipe. Thackeray masterfully identifies numerous passages in Shakespeare's work that strongly indicate that he partook of the weed but not of stronger narcotics such as cocaine. But, that was all mentioned in code; Elizabethan England did not exactly have "drug laws" as we know of them today (though substances were controlled, legal, or not legal, depending). The main problem was that drug use was considered Witchcraft, and even though smoking various things was either legal or not depending on which Monarch was in charge, Witchcraft was always going to get you ... well, stoned. As in crushed by them. (Or hung or burned at the stake, though rarely the latter ... why waste good fuel.) Read the rest of this post... | Read the comments on this post...... Read more »
Harm van Bakel, Jake M Stout, Atina G Cote, Carling M Tallon, Andrew G Sharpe, Timothy R Hughes, & Jonathan E Page. (2011) The draft genome and transcriptome of Cannabis sativa. Genome Biology, 12(R102). info:/
Urban areas can be warmer than surrounding non-urban areas because there is a lot of combustion, pavement and other structure can collect solar heat and retain it for a while, and other factors. It is not uncommon to look at a weather map where conditions for precipitation are marginal, and everywhere but the urban zone, or only the urban zone and nothing else, is showing a weather phenomenon. Because people and airports (where weather is very important) are located in or very near urban areas, it stands to reason that a lot of the data used to estimate global temperatures would be affected by any urban effects, and if urban areas are a) warmer than surrounding areas and b) increasingly warm over time then "global warming" may well be an artifact of the urban heat island effect. That wouldn't necessarily make it a hoax, but it would make it wrong. We would then have to revise our understanding of certain aspects of physics because we expect global warming to occur in CO2 levels go up, but physics has been revised before. Kepler was wrong, Newton was wrong, maybe the climate change scientists are wrong too.
Some time ago a study was funded by a number of organizations and individuals, including some who are famously skeptical of global warming (such as the Charles G. Koch foundation) in order to see if urban heat island effects could explain the famous "Hockey Stick" curve. The study was supposed to be non-biased, and it may well be, but if there are any biases they would likely be in favor off anti-Global Warming thinking, or perhaps "pro-denialist" or "anti-warmist" ... pick your term.
Well, just moments ago, the study was released and the findings are quite interesting. I have to admit, I was not expecting these findings at all, and they have caused me to change my mind about certain things. Which is fine, because that is how science works, but still, I was rather shocked. Read the rest of this post... | Read the comments on this post...... Read more »
Wickham, C., Curry, J., Groom, D., Jacobson, R., Muller, R., Perlmutter, S., Rohde, R., Rosenfeld, A., & Wurtele, J. (2011) Influence of urban heating on the global temperature land average using rural sites identified from MODIS classifications. Unknown. info:/
Rapid climate change can cause species extinction. But if a species is highly mobile or wide-ranging, then that effect may be attenuated. And, more rapid climate change would be more serious a problem than less rapid climate change. Therefore, there should be a relationship between species mobility (migration) and the rate, or velocity, of climate change vis-a-vis extinction. This is a nice set of hypotheses which have been tested in a recent paper. The abstract: Read the rest of this post... | Read the comments on this post...... Read more »
Sandel, B., Arge, L., Dalsgaard, B., Davies, R., Gaston, K., Sutherland, W., & Svenning, J. (2011) The Influence of Late Quaternary Climate-Change Velocity on Species Endemism. Science. DOI: 10.1126/science.1210173
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
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
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
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 »
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
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 »
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:/
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 »
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
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:/
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
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
Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.
If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.
Research Blogging is powered by SMG Technology.
To learn more, visit seedmediagroup.com.