LET'S GET WEIRD

npostlife: Irish potato famine mystery solved: After 170 years,...

Wed, 22 May 2013 11:27:09 -0400

Irish potato famine mystery solved: After 170 years, biologists identify pathogen that led to mass starvation
The Irish potato famine of the 1840s was caused by a plant-pathogen strain that was unknown until now, scientists said after examining dried leaves that were as much as 170 years old.
[John Miller/AP file photo]

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Wed, 22 May 2013 11:26:23 -0400

"It’s not what happens to you, but how you react to it that matters."

Wed, 22 May 2013 11:24:57 -0400

“It’s not what happens to you, but how you react to it that matters.”

- Epictetus (via lazyyogi)

opiumpoppies: Built a campsite and slept on the roof of an...

Wed, 22 May 2013 11:24:17 -0400

opiumpoppies:

Built a campsite and slept on the roof of an abandoned building last night. #urbancamping

mothernaturenetwork: Fake forest converts sunlight into...

Wed, 22 May 2013 11:16:42 -0400

mothernaturenetwork:

Fake forest converts sunlight into chemical energy

Mimicking photosynthesis, these nanowire trees absorb light to generate oxygen and hydrogen.

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Wed, 22 May 2013 02:23:29 -0400

christinetheastrophysicist: Cosmic flashes could herald birth...

Wed, 22 May 2013 02:22:01 -0400

christinetheastrophysicist:

Cosmic flashes could herald birth of black holes

The birth of a black hole may be signalled by a characteristic cosmic flash, according to researchers in the US. It was previously thought that only the most massive of black holes would produce gamma-ray bursts – narrow beams of electromagnetic radiation that shoot out of the poles of the collapsing star – when they form. But other dying stars were thought to produce a black hole without any kind of flash – seemingly disappearing from the visible sky in an event known as an “unnova”. The US researchers’ work suggests that unnovae might also have their own characteristic flash, allowing astronomers to witness the birth of stellar- and intermediate-mass black holes.

Read More.

theolduvaigorge: Punctuated Equilibrium This post is in...

Wed, 22 May 2013 02:20:35 -0400

theolduvaigorge:

Punctuated Equilibrium

This post is in response to a question asked by a follower: What is punctuated equilibrium?

To begin, this isn’t a critique of the validity of punctuated equilibrium (also called punctuated equilibria). I do not support this hypothesis and a discussion of why it is incorrect can be reserved for another post. This post only aims to explain what punctuated equilibrium is and where it came from.

Most evolutionary biologists favour phyletic gradualism, the theory of evolution as a gradual process, which is supported by data found in the fossil record and by genetic studies that provide evidence for the slow transition from one species to descendent species. However, although we have evidence for the gradual evolution of many species such as that evidenced by molars of arvicolids (e.g., species of Mimomys) during the late Pliocene and Pleistocene*, there are nevertheless gaps in the fossil record for other species. The most common and most likely explanation for these gaps contends that the fossil record is inherently incomplete because of factors such as preservation and population size. Almost all individuals that die do not fossilise. Eldridge and Gould (see below) saw little evidence for speciation at the species level but saw a great deal of evidence for speciation between larger groups. This is important to note.

A minority of scientists prefers the controversial hypothesis referred to as punctuated equilibrium, which is less of a process and more of an event. Punctuated equilibrium was first proposed in the early 1970s by Niles Eldredge and Stephen Jay Gould. It is a hypothesis that asserts that there is a high rate of evolution at times of speciation but a low rate or nil rate of evolution between these speciation events (cladogenesis). It concerns the sudden appearance of closely related taxa but does not apply to higher taxa. It “refers to both a pattern of change in the fossil record and a hypothesis about evolutionary processes” (Futuyma 2009:93).

Punctuated equilibrium sees stasis in the fossil record at points wherein taxa do not display gradual change, a period that is then punctuated by rapid evolution. Accordingly, phenotypes (and genotypes) evolve in tandem with speciation. That is to say, change does not occur slowly over a long span of time; changes in a species that lead to speciation event occur concomitantly with that speciation event. This is in direct contrast to the slow accumulation of changes that phyletic gradualism proposes. To boot, the hypothesis is yet more controversial. Punctuated equilibrium also asserts that barring populations that are undergoing speciation, phenotypes cannot evolve because of a genetic constraint. The reason this is controversial will be explained in the following paragraphs.

To understand why this hypothesis was proposed we need to understand where it came from. Punctuated equilibrium was based on Ernst Mayr’s model of “peripheral isolate speciation,” also called “founder-effect speciation,” and “peripatric speciation,” which is a kind of allopatric speciation that Mayr believed was the dominant manner of speciation. It also had roots in I. Michael Lerner’s hypotheses about developmental and genetic homeostasis. According to Mayr’s model, a new taxon (the peripheral isolate), which is at the edge of its species range, will abruptly emerge in the fossil record because the taxon evolved in a small population isolated from its ancestral species. When fully formed as a new species, it migrated to wherever it is the fossils were found. Because the speciating population was small, it is statistically less likely specimens will fossilise and furthermore, specimens are not found in the geographic range of the parent population. To be clear, founder effect, according to Mayr, is the:

“establishment of a new population by a few original founders (in an extreme case, by a single fertilized female) that carry only a small fraction of the total genetic variation of the parental population” (Mayr 1942:237).

This model maintains its foundation in phyletic gradualism but suggests that the appearance of a species in the fossil record is rapid because we simply do not have the fossils from their place of origin to prove it. In Futuyma’s words, the evolution occurred slowly “off stage” (2009:95).

Under punctuated equilibrium, speciation is an event in the geological sense. Here’s the trickier part: Presumed stasis for the duration of a taxon questions adaptation and variation in that taxon (intraspecifically) except when it occurs during the speciation event of the peripheral isolate (the descendent species). As stated above, this means that new morphologies will not evolve slowly because they are genetically constrained by gene flow**. This is a significant difference because it “decoupled intraspecific evolution from macroevolution, creating two levels of a new evolutionary hierarchy” (Erwin & Anstey 2004:188).

Again, I hope this was helpful. In truth I find this topic difficult to understand and even more difficult to explain. If anyone offers construct criticism this post can be edited. I’m here to learn too!

*Molars of taxa in the genus Mimomys are useful for dating archaeological and hominid-fossil bearing sites.

**According to allopatric speciation large populations are maintained in part by their volume and gene flow. In contrast, small populations of the peripheral isolate are not subject to the effects of gene flow that homogenise the larger population thus stymying gradual evolution.

Online references:

Berkeley. Competing Hypotheses about the Pace of Evolution

Etrilobite.com (first image)

PBS. Punctuated Equilibrium (second image)

Princeton. Punctuated Equilibrium

Ridley, M. Online resource for Evolution (2004).

Saylo, M.C., Escoton, C.C. and Saylo, M.M. 2011. “Punctuated Equilibrium vs. Phyletic Gradualism,” International Journal of Bio-Science and Bio-Technology 3(4):27-42.

Templeton, A.R. 1980. “The Theory of Speciation via the Founder Principle,” Genetics 94:1011-1038.

Tesakov, A.S. and van Kolfschoten, T. 2011. “The Early Pleistocene Mimomys hordijki (Arvicolinae, Rodentia) from Europe and the origin of modern nearctic sagebrush voles (Lemmiscus),” Paleontologia Electronica, article number: 14.3.39A (third image)

Main references:

Erwin, D.H. and Anstey, R.L. 2004. “Speciation in the fossil record” in Mark Ridley (ed.), Evolution. Oxford: 185-197

Futuyma, D.J. 2009. Evolution. Sinauer Associates

Mayr, E. 1942. Systematics and the Origin of Species from the Viewpoint of a Zoologist. Harvard University Press.

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Wed, 22 May 2013 02:20:02 -0400

sophialorens: Quentin Tarantino a.k.a Queen of Sass in an...

Wed, 22 May 2013 02:17:49 -0400

sophialorens:

Quentin Tarantino a.k.a Queen of Sass in an interviewing promoting Kill Bill, 2003. (x)

heythereuniverse: Antarctic neutrino observatory detects...

Wed, 22 May 2013 02:11:19 -0400

heythereuniverse:

Antarctic neutrino observatory detects unexplained high-energy particles | Nature

Hot on the heels of detecting the two highest-energy neutrinos ever observed, scientists working with a mammoth particle detector buried in ice near the South Pole unveiled preliminary data showing that they also registered the signal of 26 additional high-energy neutrinos. The newfound neutrinos are somewhat less energetic than the two record-setters but nonetheless appear to carry more energy than would be expected if created by cosmic rays hitting the atmosphere—a prodigious source of neutrinos raining down on Earth. The particles thus may point to unknown energetic astrophysical processes deeper in the cosmos.

“The result right now is very preliminary,” cautions Nathan Whitehorn of the University of Wisconsin–Madison, who described the new data May 15 during a symposium in Madison on particle astrophysics. “We’re not totally certain right now that it’s from an astrophysical source.” But it is difficult to explain the number and energy of the detected particles by invoking known processes within the solar system. “If this does in fact hold up with more data, and this does turn out to be an astrophysical source, then we’ll be able to address some questions in ways that were totally inaccessible before,” Whitehorn adds.

[Read more]

drawing-bored: isn’t sass an emotional response?

Wed, 22 May 2013 02:09:56 -0400

Leonard Nimoy (1968)

Zachary Quinto (2009)

drawing-bored:

isn’t sass an emotional response?

a-ttitude: worldfallsdown: unicorn-fish: joshishollywood: Th...

Wed, 22 May 2013 02:09:42 -0400

a-ttitude:

worldfallsdown:

unicorn-fish:

joshishollywood:

This is fucking hilarious. I always assumed they had the camera strapped to them on a rig omg

I love how James Cameron is clearly having more fun than both of them

lol wat

This will never stop being hilarious.

this is amazing ahahahha

"I hated high school. I don’t trust anybody who looks back on the years from 14 to 18 with any..."

Wed, 22 May 2013 01:58:58 -0400

“I hated high school. I don’t trust anybody who looks back on the years from 14 to 18 with any enjoyment. If you liked being a teenager, there’s something wrong with you.”

- Stephen King (via i-kweem)

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Wed, 22 May 2013 01:57:39 -0400

gabriella693: lmao

Wed, 22 May 2013 01:55:03 -0400

gabriella693:

lmao

strawberryskies: Arghhhh I haven’t had this stupid feeling of wanting to talk to someone but not...

Wed, 22 May 2013 01:52:27 -0400

strawberryskies:

Arghhhh I haven’t had this stupid feeling of wanting to talk to someone but not wanting to annoy them for years D; shoo stupid feelings, shooooooo!!!

climateadaptation: Why Green Is Your Color: A Woman’s Guide to...

Wed, 22 May 2013 01:51:29 -0400

climateadaptation:

Why Green Is Your Color: A Woman’s Guide to a Sustainable Career.

Ensuring women are prepared to succeed in a 21st century changing economy is critical to the financial stability of women, their families, and our country.

Why Green Is Your Color: A Woman’s Guide to a Sustainable Career is a comprehensive manual designed to assist women with job training and career development as they enter into innovative and nontraditional jobs. The guide also provides vulnerable women a pathway to higher paying jobs, and serves as a tool to help fight job segregation.

It offers women resources and information they need to enter and succeed in jobs in the emerging green economy.

The guide was created to help women at all stages of their careers — whether they are newly entering the workforce, transitioning to new careers, or returning to the workforce — identify and take advantage of opportunities in the clean energy economy.

Free career guidance for women thinking about jobs in the sciences and the environment.

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Tue, 21 May 2013 21:22:22 -0400

kqedscience: NASA Funds 3D Pizza Printer “NASA has doled out a...

Tue, 21 May 2013 21:22:12 -0400

kqedscience:

NASA Funds 3D Pizza Printer

“NASA has doled out a research grant to develop a prototype 3D printer for food, so astronauts may one day enjoy 3D-printed pizza on Mars.”