Sunday, October 30, 2005

Happy Halloween!



















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Friday, October 28, 2005

Primates and Such

My next post on ID and Human Origins won't be till Monday. In the meantime I thought I would do a post on some background information on primate evolution. Just for fun, I will do this in the form of a question and answer session.

What is a primate?
That is actually a good question and the answer is quite complicated.

What do you mean? Aren't monkies monkies?
Well yes, but it's more complicated than that. It is easier to define modern living primates. Primates as a group do share some unique, universal (among primates) features not shared by other mammals. Unfortunately, the also share features in common with other mammals.

Could you give an example of a unique (or diagnostic) feature that separates one mammal group from another?
Sure! The double pulley configuration of the astralgus (a bone in the hind limb)is diagnostic of artiodactyls.

But, what about primates?
That is a good question. Mivart first defined the order primates. His defination was:

Unguiculate, claviculate placental mammals, with orbits encircled by bone, three kinds of teeth, at least at one time of life; brain always with a posterior lobe and calcerine fissure; the innermost digit of at least one pair of extremities opposable; hallux with a flat nail or none; a well developed caecum; penis pendulous; testes scrotal; always two pectoral mammae.


Wow, that's a lot!
Actually there is more. Mivart gave his definition in 1873. In 1959 Le Gros Clark added to it:

Preservation of generalised limb structure with primitive pentadactyly (five fingers). Enhancement of free mobility of the digits, especially of the pollex and hallux (both used for grasping). Replacement of sharp, compressed claws by flat nails; development of verysensitive tactile pads on the digits. Progressive shortening of the snout. Elaboration of the visual apparatus, with development of varying degrees of binocular vision. Reduction of the olfactory apparatus. Loss of certain elements of the primitive mammalian dentition. Preservation of a simple molar cusp pattern. Progressive expansion and elaboration of the brain especially of the cerebral cortex. Progressive and increasingly efficient development of gestational processes.


That seems pretty thorough. Is there more?
Yes, there is.

I was afraid of that.
Please don't interupt. In 1967 Napier added two more:

Prolongation of postnatal life periods. Progressive development of truncal uprightness leading to a facultative bipedalism.

That's a lot of information, where did you get it?
Mainly from R. D. Martin's paper "Primates: A Definition"

Doesn't Luskin cite some paper's by Martin?
Yes, he does. I will talk about that Monday.

So what's the problem with the above definition of primates?
There are two problems. First, some of the above are actually trends, some of which are not not features. Instead they refer to developments found only in some members of the group (remember, we are not trying to trace ancestor-descendent relationships at this point. We are trying to provide a definition of an order of mammals). Second, some of these are either traits are probably primitive features of placental mammals or have arisen by convergence.

So, then how do we define primates?
Martin choose to examine living primates with an eye to creating a new definition, which I won't bore you with since it is rather long.

You said the definition applies to living primates, what about fossils?
For fossils the definition has to be modified somewhat, but first we have to talk about tree-shrews.

?Tree-shrews?
Yes, you see Le Gros Clark argued that the Tupaiidae are more closely related to primates than to any other placental mammal and should be included in the order primates. This has been argued about ever since. Martin used tree-shrews as a test case for his definition of primates and decided (correctly, I think) that they were not primates.

That's a pretty scientific approach!
Yes, it is. Paleoanthropology has a well developed scientific methodology and a rich body of theory to draw on.

So what about the fossils?
Since we have only skeletons to examine the definition has to be contracted somewhat. This is what is left:

Well developed, divergent hallux with flat terminal phalanx in the foot. Elongated distal segment of the calcaneus. Relatively large, convergent orbits with restricted interorbital distance. Postorbital bar present; ethmoid exposure in the orbit possible (depending in interorbital distance relative to skull size). Petrosal bulla. Relativly large braincase. Sylvian sulcus on endocast. Dental formula maximally 2.1.3.3/2.1.3.3. Premaxilla short; upper incisors arranged more trnsversly than longitudally. Molars with low, rounded cusps. Lower molars with raised, enlarged talonids.


So, does it identify fossil primates?
Yes, it does. According to this definition omomyids and adapids, for example, are primates.

What about plesiadapids?
The jury is still out on this issue.

Tomorrow: Omomyids, Adapids and Anthropoid Origins.

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Thursday, October 27, 2005

Intelligent Design and Human Evolution: Part II

Turning to the next section is like a breath of fresh air - even though it's completely wrong at least it's capable of being understood.

Limitations of Paleoanthropological Methods, Datasets, and Studies

In this sections Luskin purports to critique palaeoanthropology. He starts out with a quote by Gould to the effect that "most hominid fossils...are fragments of jaws and scraps of skulls" and Medawar to the effect that paleoanthopology is a humble and unexacting kind of science. Later in the section he claims that complete skulls are rare finds in paleaoanthropology. I suspect he is quote mining, but it really doesn't matter, because he is still wrong. For example, a halfhearted attempt to count the number of fossils mentioned in Conroy's Reconstructing Human Origins yielded over 2400 specimens, quite a few of which were complete skulls. I've encountered some estimates that put the total number in the tens of thousands - hardly fragments of jaws and scraps of skulls. In terms of methodology, palaeoanthropology draws on paleontology, geology, anatomy and evolutionary biology to name a few and has a rich, sophisticated theory base to draw on.

Luskin then claims that "A single skull...only provides one data point for an entire species and tells little about full ranges of morphological variation, extent sexual dimorphism and even the species true general form (whatever that is) through time. (pg 4)" At Omo over 500 specimens have been found representing gracile and robust australopithicines and early homo. At Sterkfontein over 600 specimens representing over 50 individuals from Australopithecus africanus, A. robustus and Homo habilis. At Makapansgat over 30 specimens representing approximately 12 individuals from A. robustus and H. erectus. At Hadar over 250 specimens representing approximately 35 individuals from A. afarensis. At Atapuerca/Gran Dolina 100 specimens from 6 individuals. At Atapuerca/Sima delos Huesos 28 individuals. At Predmosti 29 indicviduals. At Dolni Vestonce 35 individuals. At Krapina 800 specimens representing over 80 indivuals. At Vindija 80 specimens. At Skhul 10 individuals. At Shanidar 9 individuals. Whats missing from the list I just presented are sites such as Olduvai Gorge and Sangiran, among others. The amount of diversity in terms of morphology in the above list is certainly adequate to characterize the full range of variation for most of the species we are familiar with.

Coming soon: The Fossil Record of Non-Hominid Primates.

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Chimps and Language: An Update

Carl Zimmer has someinteresting thoughts on chimps and language.

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Wednesday, October 26, 2005

Intelligent Design and Human Evolution

Back in July of 2005 PCID published to articles on intelligent design and human evolution. One (Human Origins and intelligent design) was by Casey Luskin. The other (Reflections on Human Origins)is by Dembski. I will be examining both in a series of posts.

Both papers purport to offer the "Intelligent Design theory of human evolution. What they being, though, is a strange mix of creationist arguments and punctuated equilibria. I will start with Luskin.

Two Views of Origins

This section of Luskin's paper lays out the differences between "blind natural processes" and ID. After a brief recapitulation of the paleoanthro version of human origins Luskin lays out the ID case. According to Luskin some proponets of ID argue there are limits to the amount of change in genetic information possible through "Darwinian processes" consequently, they have proposed a new taxonomic catagory. The new catagory is the "basic type" (where have I heard that before - oh wait from Gish, Morris and company). The basic type is defined as " ...a group of organisms related through ancestry that initially acquired their fundamental genetic programs through design, and not through ancestry with some other type of organism." Luskin continues "Because their genetic architecture is distinct, members of one basic type cannot interbreed to produce offspring with members of another basic type. The converse is not necessarily true as some species which cannot interbreed could be members of the same basic type." (pg. 2)

My first thought on reading this was "huh". So I reread it several times. A new taxonomic catagory? Okay, where does it fit in the taxonomic scheme of things? Between species and genus, between genus and family? Between higher units? Better yet, why do we need another catagory? I still haven't figured out what the next bit means. I understand a group of organisms related through ancestry... Then he threw a curve with ...that initially acquired their fundamental genetic programs (though I don't quite know what a fundamental gentic program is) not through ancestry with some other organism. So which is it? Are they related or not? Is this trying to say that, say prosimmians are a basic type in that they are related by ancestry but don't share fundamental gentic prgrams with anthropoids. Oh well, skip that let's move on. One basic type can't interbreed with another because of different genteic architecture yet some species which cannot interbreed could be members of the same basic type? Then what good is the lack of inbreeding as a criteria for distinguishing basic types? I'm confused about this so let's move on to how basic types appear in the fossil record and worry about definitions later. Apparently, basic types appear suddenly in the fossil record and will be different from previously existing critters. "This infusion of information could be revealed in the fossil record as a 'quantum or discontinuous in specified complexity or information'". I can't help thinking they are stealing from Gould and Simpson here.

After laying this out, Luskin lays out the purpose of the paer, which is to test the hypothesis that some groups of "upper" primates were intelligently designed by looking at the fossil record and asking which groups belong to distinct basic types. So apparently, discovering a basic type is enough to justify the inference of intelligent design. Considering the tortured explanation of what a basic type is one thinks anything could be a basic type.

Coming soon: Limitations of Paleoanthropological Methods, Datasets and Studies.

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Memery

Homework has been assigned by my blogfather so here it goes...

1. Of all the books that you have eventually finished after many starts & stops, which one took you the longest and how long did it eventually take?

Like PZ I choose "The Structure of Evolutionary Theory". I started it about a month and a half ago - still working on it. Between the recent move (and all the packing) and frequent stops to think about what Gould is saying it's taking a little longer than I anticipated. I beginning to fear I may have to start over to pick up the argument... It's kind of like the "Song that Does Not End" on Lambchop. I think I'm doomed to endlessly read and reread it.

2. What great band (or album or song) have you heard so often, you wouldn?t mind never hearing again even though you still think the band (or album or song) is great?

That's a toss up between "Free Bird" and "Simple Man" both by Skynyrd. I lived in the south for about six years and am sick unto death of these two songs...

3. Which cliché or often cited quote needs to be placed in quarantine for a few decades?

"Teach the Controversy" "Fair and Balanced" or maybe " ______ (insert state name here) values" as in "My opponent doesn't represent Missouri (or whatever) values"

4. During the 1990s "Compassion Fatigue" received a lot of press, now the media is giddy with "Donation Fatigue". What will be the next trendy fatigue?

Missing White Girl Fatigue

5. What percentage of respondents will answer "meme fatigue" to question #4?

Fortunatley, I read PZ's post and knew better than to answer Meme Fatigue.

I think I'll pass this on to:

Oldwhitelady at It's Morning Somewhere

Henry at Webiocosm

Aydin at Snail's Tails

and

Duane at Abnormal Interests

Oh, and let me just point out that we Spawn of Pharyngula moved out in the blogosphere so we didn't have to tidy our rooms or do homework!

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Tuesday, October 25, 2005

"Junk" DNA and Fruit Flies

Added 11/2/05: Welcome visitors from Evolgen. Make yourselves at home, feel free to look around and if you like what you see do come back! I should mention I agree with Evolgen that "Junk DNA" is a term that should be dispensed with.



Genetics is an interesting, if mind numbingly complicated, subject. As you all know genes are composed of four nucleotides that form pair bonds with each other (to be simplistic). Adenine pairs with thymine and guanine pairs with cytosine. Three base pairs form a codon, etc. Traditionally, a gene is defined as a segment (i.e. series of codons) that code for a polypeptide chain or specifies a functional RNA molecule. This brings us to repetitive DNA. Repetitive DNA consists of nucleotide sequences that occur several times, either in tandem or are dispersed. For example, the genome of the kangaroo rat contains over 50% repetitive DNA in the form of three, localized, repeated sequences. These are AAG, TTAGGG and ACACAGCGGG. Each sequence is repeated from one-two billion times. Another type of repetitive DNA is dispersed throughout the genome and are divided into two major types: short interspersed repeated sequences and long interspersed repeated sequences (of which their is only one in the human genome). A number of mechanisms have been suggested for the creation of repetitive DNA including gene duplication, transposition, unequal crossing-over and replication slippage. The problem is, however, what function the repetitive sequences serve. Four possibilities have been suggested:
1) They perform essential functions, such as global regulation of gene expression. This implies that removal of repetitive DNA will have a deleterious effect.
2) Repetitive DNA is useless "junk" DNA and it's loss will have no effect of fitness.
3) It is a fucntionless parasite
4) It has a structural function unrelated to carrying genetic information. For example, it may affect chromosomal architecture such as curvature.

Recently, a study was done which seems to support the first possibility. Here is a little more background:

“Sequencing of the complete genome in humans, fruit flies, nematodes and plants has revealed that the number of protein-coding genes is much more similar among these species than expected,” he says. “Curiously, the largest differences between major species groups appear to be the amount of ‘junk’ DNA rather than the number of genes.”

Using a recently developed population genetic approach, Andolfatto showed in his study that these expansive regions of “junk” DNA—which in Drosophila accounts for about 80 percent of the fly’s total genome—are evolving more slowly than expected due to natural selection pressures on the non-protein-coding DNA to remain the same over time.

“This pattern most likely reflects resistance to the incorporation of new mutations,” he says. “In fact, 40 to 70 percent of new mutations that arise in non-coding DNA fail to be incorporated by this species, which suggests that these non-protein-coding regions are not ‘junk,’ but are somehow functionally important to the organism.”


The research found that a large amount of the functional divergence between Drosophila species was exhibited in the "junk" regions.

(The info on repetitive sequeces came from Li and Graur's 1991 book "Fundamentals of Molecular Evolution")

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From the Mouths of Babes - Well Teenagers Really

So, the afarensis family is watching the news and they are talking about yesterday's suicide bombing in Iraq and the youngest afarensis offspring says "Ya know, this has been going on for several years. I don't know who we are fighting and what we are fighting for, I'm so confused." Pretty much summed it up.

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How Fossils are Made


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Monday, October 24, 2005

Blog Lineages

Pharyngula mentions that The Politburo Diktat is trying to trace blog lineages - who inspired who to start blogging. Here are the questions to answer - leave a comment at his place:

1) Blogfather or Blogmother (Just one): Pharyngula - I had been a lurker and PZ made explaining biology concepts look sooo easy, I decided I could do it to. To my intense shock, it's not as easy as he made it look!

2)Blog Birth Month: 10/2/04 4:50 AM.

3)Blog Spawn (have you inspired anyone to start blogging?): Alas, no! I would never, I'm not that kind of hominid! Well, okay, not to my knowledge - but if I have inspired you to start blogging let me know.

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Sunday, October 23, 2005

Hadar Pictures

This site is kind of cool! It contains pictures of Hadar (where Austalopithecus afarensis was discovered)! Below is an example.



It is AL827-1, a (left) femur discovered in 2000.

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Chimpanzees and Language

The origins of human language has always been a controversial subject. Witness the cranky exchanges after Lieberman claimed neandethals were not capable of language. The ability of apes to use language is even more controversial. Whether one is discussing the Gardner's attempts to teach a chimp english, or attempts to teach chimps and gorillas sign language, there is always a large amount of skepticism. The following research will probably generate a large amount of skepticism as well.

According to National Geographic News researchers at the University of St. Andrews in Scotland have discovered that chimps use certain distinctive grunts to communicate about food:

At the Edinburgh Zoo the chimps make high grunting noises when they find bread, a food they seem to like, and low grunting sounds when they find apples, which they apparently don't care for very much, according to the study, published last week in the journal Current Biology.

After noting the different types of grunts, the researchers set out to see if other chimps listening to the grunts interpreted them the way the researchers had ("bread" and "apple"). The researchers found that the listening chimp did seem to understand what the grunts mean.

The scientists recorded the grunts and played them to a chimp in the pen. When the chimp heard the "bread" grunt, the ape looked in the place in the pen where bread is usually found. When the "apple" call was played, the chimp searched appropriately for an apple.

"It shows that, by simply listening to each other's calls, chimpanzees can infer what kind of food the caller has found," said researcher Katie Slocombe, who worked with colleague Klaus Zuberbuhler on the project.



The researchers argue that these calls are referential signals but caution that:

"We don't know yet how specific these calls are—i.e., whether they specifically refer to bread or apples or whether they simply label highly preferred food [such as bread] and less preferred food types [such as apples]. We are planning further experiments to test these two possibilities," Slocombe said.


Over and above the issue of language, there may be another social function to these grunts:

Study co-author Zuberbuhler believes that the grunts serve a social function, since the chimps hardly ever make the noises when they are eating alone.

The grunts may be a call to dinner, Zuberbuhler says. "Chimps may find it genuinely unpleasant to eat without others doing the same."


*snip*

The possible dinner-bell grunts may be related to certain human vocalizations, Zuberbuhler said.

"We don't like to eat in the presence of others who are not eating," he said.

"In many cultures humans coordinate the timing of starting a meal, for example, with vocal cues such as 'bon appetit.'"


I, for one, can't wait to see the results of the planned follow up research.

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Saturday, October 22, 2005

New Stone Age Site found in the Sahara

According to National Geographic News:

The seven nearby sites include an extensive cemetery and represent one of the largest and best preserved concentrations of ancient skeletons and artifacts ever found in the region, researchers say.


Some back ground from the expedition website:

"...the desert has waxed and waned since the last Ice Sge to eventually become the expanding desert we know today."

As the lakes evaporated and disappeared 6,000 years ago, the people that had based their livelihood on its aquatic life, the Kiffians, were replaced by the first pastoralists of the Sahara, the Tenereans. This next group of people tended herds of just-domesticated African cattle on the grasslands between the encroaching dunes. These cattle herders, the Tenereans, lived from about 5,500 to 3,500 years ago. Our site contains their tools and ceramics, including beautifully made green stone disk-shaped axes. All of these transitions were happening before the first pyramid in Egypt was ever constructed.


Again from National Geographic:

The site may not have been continuously occupied. But it was likely inhabited for much of that time, which was a crucial one in early human history.

During the New Stone Age, humans moved from hunter/gatherer societies to become early agrarians who domesticated plants and animals.


*snip*

Tools such as large pottery and heavy grinding stones suggest that Kiffian peoples may have occupied the ancient lakeside area at least semi-permanently, Garcea says.

Scientists know that by about 6,300 years ago the Sahara's first pastoral people, the Tenereans, began tending herds of newly domesticated cattle.

And while the expedition team found remains of domestic cows and asses, researchers are uncertain whether Tenerean peoples occupied the particular dig site.


*snip*

The team says the site's human remains were most striking. Members found hundreds of skeletons in the site's large cemetery, some still adorned with ancient jewelry.

The researchers found tools, such as precision stone blades, bone hooks, pottery stamps, and other artifacts, in graves and other site locations.

Some artifacts suggest travel and perhaps even distant trade. Stone tools made of pale green volcanic rock could have their source some 50 miles (80 kilometers) distant in the Air Mountains, an area rich with period rock art.


Unfortunately, the site has attracted looters:

But archaeologists are not the only ones who have visited the historic site. Niger is a poor nation, and the temptation to profit from its rich cultural history has proven too great for some.

"We followed some 4x4 tracks that our guides said were definitely not made by tourists but by vendors going out there for stolen artifacts," Sereno said. "A photographer with our team estimates that he photographed as many as 3,000 artifacts in one day, found in shops of communities near the site."


Worse yet, because the site is in the desert it suffers from deflation, or erosion caused by the wind, and is changing rapidly:

"The wind is destroying these sites very quickly," Garcea, the Italian archaeologist, said. "I saw pictures that [Sereno] took in 2003, and you can really see the deflation."

"Some skeletons that were covered are now exposed to the surface and the hyper-arid desert conditions. In two or three years I'm sure I won't be able to see some of the things that we can study now," she added.

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New Digs at Teotihuacan



From National Geographic News:

The size of Shakespeare's London, Teotihuacán was built by an unknown people almost 2,000 years ago. The site sits about 25 miles (40 kilometers) north of present-day Mexico City. Temples, palaces, and some of the largest pyramids on Earth line its ancient main street.

Scientists believe Teotihuacán was the hub of trade and commerce in Mesoamerica until the city's civilization collapsed around A.D. 650. When the Aztecs stumbled upon the metropolis centuries later, they dubbed it the "City of the Gods," because they believed it was where the Gods met to create the present universe and sun.


Research has focussed on the Pyramid of the Moon (pictured above):

Excavations also reveal that the pyramid was constructed in seven stages, each stage an enlargement of the last. The work started in A.D. 100 and ended around A.D. 400.



Japanese researchers are searching for the tomb of the ruler who ordered the pyramids construction. It has not found it yet but:

Sugiyama has made some intriguing finds, including dozens of beheaded people with bound hands. The bodies suggest bloody sacrificial rituals ripe with symbolism of military power, he said.


Analyses by Spence of the University of Western Ontario suggest the sacrificed victims came from outside Teotihuacán, possibly as captives brought back from distant territories or battles.

The clues come from oxygen isotopes in bones, which act as geological markers. "They tell you where a person was at a particular time," he said.

Climate and altitude are among factors that affect the isotopes. The isotopes found in remains of pyramid victims differ from those unearthed in city homes.


Researchers also examined the teeth of the victems looking at the growth lines or perikymata:

"Basically growth stops as the body concentrates on survival and repair," he said. "Then as the stress passes, the growth continues again. But there's a line left in the tooth that represents the stress episode."

Because teeth only grow during childhood, scientists can put a general age to when the stress happened. These signatures of bodily stress remain in adult teeth.

"We have shown that in the last century of the city there is a growing problem of some sort. We get more and more indications showing up in adult teeth," he said.


There are two competing hypothesis for the destruction of Teotihuacan. One is that the city was destroyed by invaders from the outside. The other is:

Spence, however, says the evidence suggests to him the fires were set during an internal revolt.

According to his theory, the deteriorating health of the city's poor was likely exacerbated by a drought or a disruption to the food supply. This spurred a revolution against the ruling elite and their symbols of power—temples, pyramids, and palaces.

"The destruction seems to have skipped the vast majority of the city and focused on the elite and punished the elite. That suggests a revolt to me," he said.

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Friday, October 21, 2005

Paleoanthropology in Chad



The above is a picture of Sahelanthropus tchadensis, the seven million year old fossil from Chad. Recently a new paleoanthropology department (the first)was opened in Chad. According to BBC News:

The new palaeontology department will have space for 46 students, as well as a hi-tech laboratory to analyse fossils.

The head of the new unit, Dr Mackaye Hassane Taisso, set out his ambitions for the future.

"Listen, Toumaï is seven million years old, so our ambition is to find something older," he told the BBC.

"If we find a fossil about 10 million years old, that would be great. We are placing the bar very high, but we need to."

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Friday Stephanoidea (Wasp) Blogging



Above is a species of wasp called Megischus maculipennis. M. maculipennis belongs to the superfamily Stephanoidea - which are considered to be an ancient group of parasitic wasp. Today there are 323 living species in 11 genera. there are also 3 genera known from baltic amber.



They seem to be ectoparasites on wood boring insect larvae but are characterized by low host specificity. One intersting fact about Stephanoidea is that they seem to be characterized by high degrees of endemism. From The Tree of Life:

Stephanids live mostly in tropical forests, but many inhabit desert or semidesert areas ..., reach high latitudes (e.g., Megischus bicolor in Canada, Stephanus serrator in Germany, Hemistephanus artiosulcatus in Argentina), or are endemic in many oceanic islands throughout the world. The genera are normally restricted to one or two particular zoogeographical regions, such as Hemistephanus (Neotropical), Parastephanellus (Oriental and Australian), and Foenatopus (mostly Oriental and Afrotropical). No stephanid species, except for one introduced taxon, has been found in more than one zoogeographic region, suggesting a considerable degree of endemism ... There are no species of stephanids known from Chile.


Adults seem to be predominantly diurnal, but some species are attracted to light traps ..., suggesting that flight activity may start in, or extend to crepuscular hours. Flight and other movements are usually slow and weak, but cryptic coloration and behavior contribute to make many species inconspicuous in their habitat.

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Thursday, October 20, 2005

Bacteria, Elephants and Metabolic Activity

I'm sure someone, such as Coturnix at Science and Politics could write a better post on this subject, but I find it interesting so I'm going to have a go at it (although I'd love to see what Coturnix could make of it).

It is a truism in biology that smaller animals have higher metabolic rates than larger ones. Think of the shrew, and other such animals, that have to eat a large percentage of their body weight in order to survive. Recent research has qualified this picture somewhat. Researchers at the University of California have performed an extensive study and come up with some interesting results. A little background from Science Daily:

"...all living organisms have to transport energy obtained from food they eat to support the working of their internal organs, such as the brain or heart. The larger the organism, the further away are the organs from the body surface. “This makes energy supply more and more difficult for larger organisms,” he said. “For example, bacteria have to transport the obtained food over less than one micron, which is their body length, while the distance between an elephant's trunk and an organ such as its brain or heart is about ten million times longer."


With that in mind, the researchers compared metabolic rates in various groups of organisms ranging from bacteria (over 80 species were included) to elephants to test the idea that smaller animals are more metabolically active than larger animals:

But a new study led by Bai-Lian Li, professor of ecology at UC Riverside, shows that this is true only for organisms that are closely related evolutionarily and have body masses differing by no more than 6-7 orders of magnitude – about the difference in body mass between an elephant and a shrew.

For a pair of organisms that don't meet these conditions, that is, organisms that are not closely related evolutionarily and whose body mass difference exceeds the 6-7 orders of magnitude range, the researchers find that the small organism consumes about the same amount of energy per unit mass as the large organism: 1-10 watts per kilogram of body mass in the resting state of the organisms.


Since bacteria and elephants are not closely related, in evolutionary terms, and since an elephant is more than 6-7 times the size of bacteria:

"...elephants, ..., appear to be capable of supplying their tissues at a rate similar to that of tiny bacteria."


Even more interesting:

The researchers’ analysis also shows that the rate of energy consumption per unit body mass declines with growing body size in groups of evolutionarily close organisms, such as mammals. For example, one gram of an elephant’s body uses up 25 times less energy than does one gram of a shrew’s body, accounting for why shrews have to eat more often than elephants. On the other hand, a bacterium, which is not closely related to an elephant in an evolutionary sense, consumes approximately the same energy per unit body mass as the elephant.


Which may help explain trends towards large size in a lot of lineages throughout evolutionary history.

Finally, this is the most fascinating part:

So far, life scientists have held the view that the properties of living organisms are shaped by the changing external physical environment to which the organisms must continuously adapt. The new study posits, however, that living organisms are able to overcome the physical limitations imposed on them by their own physical properties and their external environment in order to maintain optimal, biochemical characteristics, such as the mass-specific metabolic rate the researchers studied.


Although, I'm not sure if the bolded sentence isn't just an alternative way of phrasing the first sentence. If organisms are continuosly adapting to the changing physical environment aren't they overcoming the physical limitations imposed on them by their own physical properties and their external environment in order to maintain optimal, biochemical characteristics?

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Wednesday, October 19, 2005

Sigh

Oh, Well. Better luck next year...

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GO CARDINALS!




GO CARDINALS!

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More on Bone Eating Sea Worms

As I mentioned in a previous post some sea worms feed on whale bones. BBC News is reporting some have been discovered off the coast of Sweden (they were previously known only off the coast of California).



above is a picture of the Swedish species. Below is a scanning electron micrograph of the sea worm.



Here is another picture:



Here is what is know, so far:

Osedax worms are about 1-2cm in length.

A scanning electron micrograph shows up remarkable detail in the North Sea worm
They root themselves to the whale bones which they then plunder for oils with the help of symbiotic bacteria. The worms' flower-like plumes pull oxygen from the water.


There is a mystery:

Their reproductive system is extraordinary - certainly in the case of the Pacific Osedax.

"The female Pacific worms keep males inside their tube as a sort of little harem that fertilises eggs as they are released into the water column," explained Dr Glover.

"We're not sure what's happening with the reproductive biology of the Swedish worms yet. We've only got females; we haven't found any males. It's a bit weird."

Scientists have established that all of the Osedax species so far identified appear to be closely related to vestimentiferan tubeworms, which are found only at the volcanic cracks in the ocean floor called hydrothermal vents.


There is also a fly in the ointment. Since these worms live on whale falls (I. E. carcasses of dead whales that sink to the ocean floor) it is believed that whale carcasses act as stopping points that allow organisms to move around the ocean floor. If whales have low population numbers or are extinct this "island hopping" can't work:

What concerns researchers is that the commercial hunting which so devastated whaling populations would also have severely curtailed this activity by reducing the incidence of whale fall.

It may even have led to the extinction of some bottom-dwelling organisms that depended on this rare but concentrated nutrient supply.

Read more!

Tuesday, October 18, 2005

Swimming Dinosaurs

Recently tracks have been discovered in Wyoming that show that dinosaurs swam. According to the GSA this is the first evidence in Wyoming of this kind of behavior:

The tracks are embedded in a layer of rock known as the Middle Jurassic Bajocian Gypsum Spring Formation, a 165- to 167-million-year-old rock formation that contains fossilized remains of a marine shoreline and tidal flats. Geologists believe an inland sea, called the Sundance Sea, covered Wyoming, Colorado and a large area of the western United States during the Jurassic period from about 165 million years ago to 157 million years ago.


Debra Mickelson of CU-Boulder’s geological sciences department said the research team identified the tracks of the six-foot-tall, bipedal dinosaur at a number of sites in northern Wyoming, including the Bighorn Canyon National Recreation Area. “It was about the size of an ostrich, and it was a meat-eater,” she said. “The tracks suggest it waded along the shoreline and swam offshore, perhaps to feed on fish or carrion.”


The dinosaur does not have a name, although Mickelson is continuing to look for bones and other remains that could be used to identify and name the new species. “This dinosaur is similar to a Coelosaur,” she said. “It is a dinosaur with bird-like characteristics and is a possible ancestor of birds. It lived in a much earlier time period and was very different from larger dinosaurs like T-Rex or Allosaurus.”


The tracks are of different sizes and were deposited at about the same time, according to Mickelson, revealing that the dinosaurs likely traveled in packs and exhibited some variation in overall size. “Further research into the geologic record and depositional history of the region supports our conclusion that the dinosaurs were intentionally swimming out to sea, perhaps to feed,” she said.

Read more!

Monday, October 17, 2005

Global Warming and Fossils

I'm still working on a post on Homo floresiensis. In the meantime...
"Prehistoric global warming episodes from massive atmospheric pollution involving carbon dioxide and methane could have created and preserved "mass kills" of wildlife..."

According to recent research previous episodes of global warming may have played a role in fossil preservation. The research, conducted by Oregon geologist Gregory Retallack, involved comparing thousands of well preserved assemblages of fish, crustaceans, insects, starfish among others. According to the article, during the past 500 million years there are 41 instances of exceptional preservation:

Such exceptional assemblages were thought to have been preserved in environments that were unusually low in oxygen, highly saline, very cold, or extremely dry. What was not suspected until the new compilation was the global distribution of other exceptional fossil deposits of the same ages. Independent estimates of atmospheric pollution crises come from studies of carbon anomalies, microscopic pores of fossil leaves and climatic indicators from fossil soils. Methane outbursts from volcanically intruded coals and submarine gas hydrates are prime suspects for these lethal atmospheric pollution events.



"Lowered levels of oxygen can kill fish and other creatures in marginally aerated environments, and also preserve their carcasses from dismemberment and decay," said Retallack. "Data from carbon anomalies and microscopic leaf pores indicate that some of these killer greenhouses ramped up, within only a few thousand years, to intolerable levels of more than 10 times the modern level of atmospheric carbon dioxide. What stopped them from continuing on to a sterile greenhouse atmosphere like that of Venus? It was the widespread death and burial of animals and their carbon which created fossil bonanzas, the likes of which may have saved us from the heat sterilization experienced by our sister planet."

Read more!

Homo floresiensis: More Pieces of the Puzzle

The past week has seen a flurry of activity concerning Homo floresiensis. Starting with an article in the letters section of Nature (kindly sent to me by Aydin at Snail's Tales)and continuing with articles in Nature's News and News and Views Sections. Several bloggers have posted on it as well. Carl Zimmer at Corante has an interesting post on the subject. Orbis Quintus has some interesting thoughts as well. Perhaps, the most interesting though, is Hawks here, here and most importantly here.

My first thought on seeing the pictures of some of the other bones discovered was "Wow, they are really robust" but I'll get to that later. The main article ("Further Evidence for Small-Bodied Hominims from Late Pleistocene of Flores, Indonesia") gives some details on the stratigraphy of the cave where the fossils where found - including spots where samples for thermoluminescence were taken, talks about the tools and faunal remains and provides a table listing the remains that have been recovered so far. There is a new mandible (LB6/1) that is slightly smaller in size than the original. More importantly, there is some post cranial material. Which is were things really get interesting. As I mentioned above, the post cranial material is robust. The pictured bones are compared with similar bones from a human pygmy and the differences are noticable. For example, the humerus has a greater (midshaft circumference wise) as does the recovered tibia. The humerofemoral index (a ratio comparing the lengths of the humerus and femur) is the same as for AL-288-1 (Lucy) and the blades of the pelvis are flared antero-laterally which implies an australopithicine shaped thorax (and hence indicates some climbing behavior). Because of this the authors of the paper have moved away from intepreting H. floresiensis as a dwarf H. erectus. After reading the paper and seeing the pictures I would have to agree. For example, the trochlea and capitulum of the humerus look a lot like Australopithecus robustus - TM 1517 or KNM-ER 739 for example. One other interesting feature was the humeral torsion (rotation of the head of the humerus relative to the plane of the distal end) which is in the range of gibbons and macaques. Humeral torsion occurs mainly when there is a laterally facing shoulder joint and it is necessary for the elbow to flex and extend in an anteroposterior plane. Humans and the great apes have a large degree of humeral torsion (although gorillas, the most ground dwelling, have the least amount of the three). Overall, what the morphology says to me is that this is something new and we need to interpret it in it's own right rather than trying to force it into current species.

Perhaps, the saddest part is that the researchers have been denied permission to return to Liang Bua.

Read more!

Saturday, October 15, 2005

Which Dromaeosaurid Are You?

Via Pharyngula


Deinonychus2
Deinonychus - Fun and playful, yet very set on pack
structure. Often an annoyance to larger
'raptors, such as Utahraptor.


Which Dromaeosaurid Are You?
brought to you by Quizilla


Fun - Check
Playful - Check
Often an annoyance... - That's a big yes per Mrs. afarensis!

Read more!

Friday, October 14, 2005

A Step Closer to Understanding Anthropoid Origins



Anthropologists in the Fayum (where else?) of Egypt have uncovered several interesting fossils that shed some light on the origins of anthropoids (old and new world monkies). Unlike previous finds, these fossils were found at a relatively new locality in the Fayum.

According to paper coauthor Elwyn Simons:

"...analyses of the teeth of the two species clearly place them as members of a group called parapithecoids, known as "stem" anthropoids because they constitute the species of early creatures from which the subsequent "crown" anthropoid line arose. "The finding of these parapithecoids from such an ancient time confirms that crown anthropoids -- a group including all modern anthropoids -- have their earliest known beginnings in Africa," said Simons. "They show that findings by other researchers of isolated examples of possible higher primate fossils in Asia do not constitute evidence of an ancestral crown anthropoid lineage there."


Leaving the cladistic terminology aside, what this means is that these fossils are on the main line of anthropoid evolution. One of the species, Biretia megalopsis, may have been nocturnal - also important for understanding anthropoid evolution. How do we know B. megalopsis was nocturnal and why is this important?

"...a tooth root from the species Biretia megalopsis is truncated, indicating that it had to make room for the larger eyesocket of a nocturnal animal."

"These finds seem to indicate that Biretia megalopsis must have had very large eyes, and so was likely nocturnal," said Seiffert. "This has never been documented in an early anthropoid. The simplest explanation is that Biretia's nocturnality represents an evolutionary reversal from a diurnal ancestor, but that conclusion is based solely on the probable pattern of relationships. If down the road we find out that our phylogeny was wrong, Biretia could end up being very significant for our understanding of the origin of anthropoid activity patterns."


In other words, being diurnal (active during the day) is the ancestral condition for anthropoids, apes and humans and B. megalopsis evolved away from that condition.

Read more!

Thursday, October 13, 2005

More Organic Chemicals Found in Space

Scientists associated with NASA's Spitzer Telescope have discovered polycyclic aromatic hydrocarbons:

"NASA's Spitzer Space Telescope has shown complex organic molecules called polycyclic aromatic hydrocarbons (PAHs) are found in every nook and cranny of our galaxy. While this is important to astronomers, it has been of little interest to astrobiologists, scientists who search for life beyond Earth. Normal PAHs aren't really important to biology," Hudgins said. "However, our work shows the lion's share of the PAHs in space also carry nitrogen in their structures. That changes everything."


This is important because:

"Much of the chemistry of life, including DNA, requires organic molecules that contain nitrogen," said team member Louis Allamandola, an astrochemist at Ames. "Chlorophyll, the substance that enables photosynthesis in plants, is a good example of this class of compounds, called polycyclic aromatic nitrogen heterocycles, or PANHs. Ironically, PANHs are formed in abundance around dying stars. So even in death, the seeds of life are sewn," Allamandola said.


Looking back over the years it is totally amazing to me how many different types of organic chemicals have been found in outer space. Once upon a time it used to be thought that outer space was barren of organic chemicals and origins of life research focused on chemicals believed to be present on early earth. It seems the picture is changing...

Read more!

Blood Drinking Spiders!



The above is a jumping spider native to Africa:

Evarcha culicivora, is found only around Lake Victoria in Kenya and Uganda. A species of jumping spider, or salticid, it usually hunts insects on tree trunks and buildings. It stalks its prey rather than trapping it in a web.


At the moment it is pretty unique. You see it has a taste for mammal - and human - blood! How do we know this? Scientists recently conducted prey preference experiments. This is how it works:

Lab experiments conducted near Lake Victoria showed the spider preferred female mosquitoes fed with human blood over all other prey, including male mosquitoes, which don't feed on animal blood.

Tests of the spider's prey preferences showed it went for blood-engorged female mosquitoes in 83 percent of cases when offered a choice of two similar-size insects.

When it came to making a choice based on smell alone, with the two meal options hidden from view, around 90 percent of jumping spiders selected the blood-filled mosquito.


Although many spiders have relatively poor eyesight—those that use webs to trap prey have no need for acute vision, Nelson says—jumping spiders are an exception.

"Salticids are predators that actively search for prey and mates and typically do not build webs," she said. "They have evolved eyes that support high-acuity vision suited to their active lifestyle."

Spiders don't have the skin-piercing mouth parts needed to feed directly on human blood, but the mosquito-munching jumping spider appears to have got around this. The strategy has other advantages as well, Nelson points out.

"Blood-feeding is a dangerous activity," she said. "Animals that are bitten have a swatting response, and often the insect is killed."


So, essentially the spider has come up with a method to avoid being swatted and still specialize on blood.

The study team suspects a blood meal is also biologically important to E. culicivora.

They say spiders expend a lot of energy breaking solid food down into liquid by injecting their prey with digestive enzymes.

"Perhaps blood is a ready-made, nutrient-rich liquid meal," Nelson said.


Although spiders creep me out, I think this is a fascinating study in evolution. Mosquitos specialize on blood as a food source as does E. culicivora but both have evolved different methods to obtain it. It would be interesting to find out if mosquitos were E. culicivora's primary prey or if this is a recent addition to their diet. It would also be interesting to see if there is a closely related species that doesn't feed on mosquitos (I'm thinking of Rhagoletis pomonella).

Read more!

Wednesday, October 12, 2005

I'mmm Baaack!

Tokk a few days longer than I thought to get moved. Today was actually the first day I'v had to mess with the computer. I'll be visiting some friends in the blogosphere and start regular posting tomorrow.

Read more!

Thursday, October 06, 2005

Poor Me

Since I'm moving during the next couple of days I will be without the internet until Mondayish (assuming my DSL provider isn't fibbing) so if you seen a haunted, haggered man roaming your neighborhood crying "My kingdom for a modem connection" take pity - it will probably be me...
When the move is done and DSL restored I will have plenty to blog about - I've been collecting ideas all week!

Read more!

On the Other Hand...

Little Blunt doesn't want to violate the law:

Robinson said that governors who order flags flown at half-staff in response to a soldier being killed while serving the country as opposed to the state are in violation of the law, according to general counsel Terry M. Jarrett's interpretation.


Here is what it's about:

Two St. Louis anti-war activists are challenging Gov. Matt Blunt to respond to the deaths of soldiers as several other states do: by flying flags at half-staff when a soldier from the state dies in the line of duty.


*snip*


Several other governors, including Illinois', issue such orders when soldiers from their states are killed. But Jessica Robinson, Blunt's press secretary, said Wednesday that neither Blunt nor any other governor had the authority to make such an order.

"As a veteran, Gov. Blunt deeply respects the sacrifices and has personally mourned the loss of those who have been killed in action," Robinson said. "But lowering the flags would actually be contingent on a presidential directive. ... Our general counsel's interpretation of the law is that the opportunity and authority rest with the governor when it's (a situation involving) state service and with the president when it's federal service."


*snip*

Joyce Doody, executive director of the National Flag Foundation in Pittsburgh, said governors do have the authority to order flags flown at half-staff. If asked, however, her organization suggests governors opt to fly state flags instead of U.S. flags so that the U.S. flag isn't too often at half-staff.

Her organization has not tallied how many states fly flags at half-staff in response to the deaths of soldiers. A review of news releases and articles shows that Illinois, California, Michigan, New Mexico, New Jersey, Kentucky, Oregon, Minnesota, Wisconsin, Indiana, Vermont and Pennsylvania are among the states whose governors have ordered either U.S., state or both flags to be flown at half-staff in response to the deaths of soldiers.


*snip*

Gerardo Cardenas, a spokesman for Blagojevich, said the governor had the authority to make the proclamation because he is commander in chief of the state's National Guard.

"This does not constitute any violation or any trespassing on presidential authority," Cardenas said. "This is a gesture that shows our respect for these soldiers who give up their lives ... We're respecting their sacrifice and honoring their service in a proper way."


Thank God we have Blunt to stand up for the President and law and order! Unlike all those other governors in Illinois, California, Michigan, New Mexico, New Jersey, Kentucky, Oregon, Minnesota, Wisconsin, Indiana, Vermont and Pennsylvania who hate America and violate the law. Even more horrifying they usurp presidential privilege! To Gitmo with them, I say! (Note to conservatives: I do not really mean this, I'm being sarcastic, so as much as you'd like to, please do not send all those governors to Gitmo.)

Read more!

The St. Louis Post-Dispatch Has Picked Up the Delay/Blunt Story

Here although it's basically the same as the story I linked to in the previous post.

Read more!

Wednesday, October 05, 2005

Tom Delay and the Blunts

I just turned on KMOV (a CBS affiliate) in time to hear a story about Delay giving 100,000 to Blunt who gave it to the Missouri Republicam party. He also gave the MO Republican part 50,000 and the party turned around and gave it back. I am unclear about all the details. DeLay, Successor Blunt Swapped Donations:

WASHINGTON (AP) -- Tom DeLay deliberately raised more money than he needed to throw parties at the 2000 presidential convention, then diverted some of the excess to longtime ally Roy Blunt through a series of donations that benefited both men's causes.

When the financial carousel stopped, DeLay's private charity, the consulting firm that employed DeLay's wife and the Missouri campaign of Blunt's son all ended up with money, according to campaign documents reviewed by The Associated Press.


*snip*

The government's former chief election enforcement lawyer said the Blunt and DeLay transactions are similar to the Texas case and raise questions that should be investigated regarding whether donors were deceived or the true destination of their money was concealed.


*snip*

Hartley said he saw no similarity to the Texas case. The fact that DeLay's charity, Christine DeLay's consulting firm and Blunt's son were beneficiaries was a coincidence, Hartley said.

Much of the money - including one donation to Blunt from an Abramoff client accused of running a "sweatshop" garment factory in the Northern Mariana Islands - changed hands in the spring of 2000, a period of keen interest to federal prosecutors.


*snip*

Noble said investigators should examine whether the pattern of disguising the original source of money might have been an effort to hide the leaders' simultaneous financial and legislative dealings with Abramoff and his clients.

"You see Abramoff involved and see the meetings that were held and one gets the sense Abramoff is helping this along in order to get access and push his clients' interest," he said. "And at the same time, you see Delay and Blunt trying to hide the root of their funding.



*snip*

The DeLay group began transferring money to Blunt's group in two checks totaling $150,000 in the spring of 2000, well before Republicans actually met in Philadelphia for the convention. The transfers accounted for most of money Blunt's group received during that period.

DeLay's convention arm sent $50,000 on March 31, 2000. Eight days later, the Blunt group made a $10,000 donation to DeLay's private charity for children on April 7, 2000, and began the first of several payments totaling $40,000 to a northern Virginia-based political consulting firm formed by DeLay's former chief of staff, Ed Buckham.

That consulting firm at the time also employed DeLay's wife, Christine, according to DeLay's ethics disclosure report to Congress.

Hartley said Blunt was unaware that Mrs. DeLay worked at the firm when he made the payments, and that she had nothing to do with Blunt's group.


*snip*

On May 24, 2000 - just before DeLay left with Abramoff for the Scottish golfing trip - DeLay's convention fundraising group transferred $100,000 more to Blunt's group. Within three weeks, Blunt turned around and donated the same amount to the Missouri Republican Party.

The next month, the state GOP began spending large amounts of money to help Blunt's son, Matt, in his successful campaign to become Missouri secretary of state. On July 25, 2000, the state GOP made its first expenditure for the younger Blunt, totaling just over $11,000. By election day, that figure had grown to more than $160,000.

Hartley said Blunt always liked to help the state party and the fact that his son got party help after his donation was a coincidence. "They are unrelated activities," he said.

Exchanges of donations occurred again in the fall. Just a few days before the November election, DeLay's ARMPAC gave $50,000 to the Missouri GOP. A month later, the Missouri GOP sent $50,000 to DeLay's group.


More here.

Read more!

Monday, October 03, 2005

The Meme

Aydin at Snail's Tales has tagged me with the meme that is going around. So without further ado...

What were you doing 10 years ago? Ten years ago I was beggining what would become the second worst semester in my educational career. I was actually looking forward to the semester because I was starting the research on my master's thesis. I was going to examine some recently created methods for determining gender from the tibial plateau (really more in the way of verification on modern forensic samples). I was also going to try and apply them to zooarchaeological situations. At any rate, during the course of the semester I came down with bronchitis on three separate occasions. The third time I developed cough syncopy to go along with the bronchits - which means I passed out almost every time I coughed. I managed to muddle through the semester with GPA intact.

What were you doing five years ago? Five years ago I was working for a company that provided nurse case management for worker's comp claims (don't get hurt in Missouri is all I can say - Blunt's made it worse). I was also back at a community college taking Trigonometry and College Algebra. There is a silver lining in every cloud and somewhere along the line I saw the good in being knocked out of college (see the previous post). You see, I didn't really pick the master's thesis I wanted, mainly because I didn't have the math (if you are reading this post and want to be a physical anthropologist take math, a lot of math, chemistry, evolutionary biology and evo-devo wouldn't hurt either - neither would some good classes in comparitive anatomy). What I would have liked to have done was test Martin Bernal's theories developed in "Black Athena" concerning the ethnicity of the greeks. In particular I wanted to see if there was any biological admixture between the greeks and surrounding peoples. This would have required more math than I had so I was back in school trying to acquire the tools I needed to become the type of anthropologist I want to be.

What were you doing one year ago? One year ago I was starting the scanning department for my current employer. I was out of college, again, because my wife wanted to go and since I had a B.A. I felt it was her turn. I'm a very patient person - I'll have a Ph.D before all is said and done.

What were you doing yesterday? Writing a post on my one year anniversery as a blogger! Oh, and packing.

Five songs you know the words to? Well, that's kind of tough... Once upon a time I used to play a bamboo flute (I also used to play the trumpet - Louis Armstrong rules!) and had the sheet music to quite a lot of songs - play them enough and you learn them by heart. So, pretty much anything off Neil Young's Harvest, Stairway to Heaven, Ben (I don't know why I know the words to that - seen the movie once to often I guess). Anything off Black Sabbath's Paranoid.

Five snacks you like? Popcorn, Baby Ruth, Trail Mix, Bannanas, Milk Duds

Five things you would do with $100 million? I divide this into two sections. The selfish part: Finish my education, increase my library size significantly (this applies to books and monster movies - a weakness of mine), buy a 40 ft Hallberg-Rassy and sail to greece with my family:


They are beautiful, beautiful boats and cost a small fortune.

Then I would make sure several other family members are taken care of, which should really be included in the altruistic section. The altruistic part: endowe some scholarships in science so others could attend college. Either start an evolution research institute or maybe endowe the NCSE.

Five places I would run away to? Anyplace the sailing is good, in particular the Aegean. Greenland (as long as I wasn't unemployed). Aydin mentioned Darwin's house and that would be cool - as would the Galopagos Islands. Hadar would be fantastic as would Olduvai Gorge.

Five things I would never wear? Those skimpy swimming trunks Brazillian and Italian men wear at the beach (at least not without doing some serious exercising). This is a really tough question. I'm stumped...

Five greatest joys? Does Mrs. afarensis count? The little afarensis' too. The explosion in my brain when I have an "eureka" moment and solve a difficult problem. Sailing. Chess (although it's been awhile - I really admire the style of Aron Nimzovitch if that means anything to any of you). Fencing. Reading.

Five favorite toys: My computer obviously. Slide rules - I have five. Having a telescope and a microscope would be fun as would a digital camera.

Five people I'm tagging? Most of the bloggers I know have already done this so I'm leaving that open to whoever wants to do it.

Read more!

Sunday, October 02, 2005

Happy Blogiversary To Me

Yes, that's right! It was one year ago today that a blog named afarensis first blazed across the intellectual firmament, astounding all with it's brilliance! So I thought in this post I would look back at the past year.

Originally, I was going to name the blog "Insomnia" because I do suffer quite frequently with insomnia. The idea was to blog when I couldn't sleep. Didn't quite work out though because I tend to read when I can't sleep (for example I'm on page 526 of Gould's monumental "The Structure of Evolutionary Theory"). Here's my first post:

Up late

Well technically I woke up early and can't get back to sleep. This blog will be about science, politics and whatever else I can think of to say.


See what I mean about brilliant!

I posted six more times in October and seven times in November. In December I did not post at all. Mainly, because I was having a running battle with a creationist who claimed to be from Missouri over at Chris Mooney'sblog (whoooops! Just gave up my anonymity didn't I?).
In January I only put up three posts. I decided at that point that I needed to get more serious about blogging, so in February I vowed that I would try to post everyday and although I didn't quite reach that goal I did start posting a lot more frequently. This effort brought me my first commenter:

I was looking at various blogs and came across one that had the Book Meme. It looked like a lot of fun so while I was posting it on my own blog, I tracked it back several blogs. Anyway, I found this in one of the comment sections Good grief, there are 987 different posts referencing "page 123" in Technorati...
PSoTD | Email | Homepage | 02.17.05 - 9:28 pm | #
I clicked on that comment and one of the links was yours.


This commenter still shows up on a regular basis. Can anybody guess who it was?

Sometime during March some of the other blogs in the blogosphere started occasionally linking to my posts and several - such as Red State Rabble, Thoughts From Kansas, Dharma Bums, Pharyngula, It's Morning Somewhere and last, but not least Snail's Tails. Others started linking later, and you can find links to them in my blogroll, but these are the people primarily responsible for my sitmeter climbing.

So let's talk about that for a few. My most popular post was Wells, Centrioles and Cancer: Bad things Happen when you Believe your own Metaphor. Pharyngula linked to it and I received over 2,500 hits - as a matter of fact I still get hits on it from that link!
Ian Musgrave even showed up and made a few snarky comments about Wells! I have been averaging around 280 hits a day for the last couple of months (although lately it has dropped below 200) and at last count I have had 44,393 hits. Which surprises the hell out of me. I never thought I would have that many hits after just a year. So, to those 44,393 people I say:

THANK YOU

Since my site is devoted to anthropology, evolution and science you would think that I get my fair share of creationist and Intelligent Design trolls, but you would be dead wrong! Pharyngula and The Panda's Thumb are hogging them all! Not that I object, you understand, because I would rather blog about science than argue with the brain dead. It's been my experience that people like that know little about evolution and are instead arguing against some weird mishmash they have created in their own imagination. On the other hand, I have had several wingnuts show up. The first showed up when I announced I had joined the Big Brass Alliance. Another wingnut showed up when I did my Cindy Sheehan. This is also the longest thread to date.

In June I started a new blog dedicated to Middle School (or Junior High) and High School students, as well as those who know little about evolution but wish to learn more. The blog is called Transistions: The Evolution of Life. Anyone can contibute posts to it by getting in touch with me. I have had a wide variety of people contribute to it, in addition to the posts I have written. I am always seeking good posts that fit in with the basic mission of the blog. I am also seeking links to websites, etc, you can go here for more info on what I'm looking for.

Since this blog is about anthropology, evolution and science I have always been a littled worried. I do have a Bachelor's degree in anthropology and did two years of grad school before a car accident (I was hit by a drunk driver) and a year long concussion (I really feel sorry for those professional athletes that get concussions, they are brutal and agonizing and really affect your life) knocked me out of school (I do plan on going back - maybe soon). So I do know something about the subjects I blog about. More importantly, I know how to research a subject befor I post on it. Which is not to say I haven't goofed a time or two. I have found, however, that if you do your research your posts will be well received by the scientific community at large - even if you are not a working scientist. For exammple, Per Ahlberg sent me a copy of his Nature article on Ichthyostega after reading my first post on the subject. So let me talk a little about my blogging philosophy. I consider one of my missions, as a science blogger, to be education. I try, whenever possible, to post items that demostrate not just what science is about, but how scientists learn about the world around them. For example, my recent post on the expansion of the universe. A second example, on how scientists can study the interactions of insects and plants in the past can be found here. To me, this is a really important issue. All to often I have encountered a basic misunderstanding about how science works - and here I'm not just talking about the scientific method (such as the difference between a fact and a theory or about what the word hypothesis means). Here I am referring to the "we can learn about it because we wern't there" criticism embraced by creationists.
Having said that, like other bloggers, I tend to blog about whatever interests me. So I treated you all to, for example, a long series on Kennewick and what can be learned from one skeleton.
Finally, I am not afraid to get a little silly or goofy:



Some have claimed this is a picture of Badtux at a recent party! It's really Opus - a picture I post whenever I feel silly - although the resemblance to Badtux is striking!

Read more!

Saturday, October 01, 2005

Expansion of the Universe

This is cool (yes I know, I should be packing). Physicist Richard Price was asked a simple question by a high school student:

"He asked me if, as space expands, we all get bigger too," says Price. "I knew the standard answer was 'no', but I couldn't explain why not. And when I consulted my colleagues, neither could they."

So he decided to investigate:

Since atoms are made up mostly of empty space, with electrons "orbiting" the nucleus at distances typically many hundreds of times its diameter, it seemed reasonable to ask whether the electrons would be dragged away from the nucleus by the stretching of space. Price decided to examine the simplest system, that of a hydrogen atom, with one negative electron orbiting a positive proton. He found if the force involved - electromagnetic in the case of atoms - binding the system together is stronger than a certain critical value, the system will be entirely unaffected by the cosmological expansion.


What does it all mean you ask:

"This means that the solar system - which is quite tightly bound by gravity - doesn't expand. Your desk doesn't expand. Your dog doesn't expand," says Price. "But clusters of galaxies, which are only loosely bound by gravity, will feel this effect."

Price also found that the atoms never experience just a little stretching - either they must totally ignore the expansion of the universe or they will be completely torn apart. "This all-or-nothing effect is a startling result," says Roy Maartens, a cosmologist at the University of Portsmouth in the UK. "This question has been knocking around since the 1930s, but nobody has found this before."


The moral of the story, to me, is that you should try to explain science to as many people as possible, because the questions they ask may lead you to some interesting research.

Actually there is a second moral of the story:

Andrew Jaffe, an astrophysicist at Imperial College London in the UK believes the effect becomes interesting in so-called "big rip" cosmologies in which the universe is not only expanding, but the expansion is accelerating.

"Price's calculation still holds in this case, but you start to see the opposite effect," says Jaffe. The expansion of the universe accelerates drastically. First it overpowers gravity, ripping apart solar systems, and next the electromagnetic forces are overwhelmed. "The planets are torn apart, and then you and me, and finally the atoms that make us up are destroyed," says Jaffe. "That's not a particularly fun way to end."


Now if we could only get a restauraunt at the end of the universe...

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Biblical Curse Generator

Red State Rabble has a link to a biblical curse genorator. It's very amusing. I tried it and got:

Harken, O ye bull of Bashan, for you will be swallowed by a whale with excessively bad breath!

I wonder if it will have legs or if it will be one of those modern evoluted types with no legs!

Follow the link to Red State Rabble if you want to try.

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