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kottke.org posts about biology

God, Darwin, and biology class

posted by Jason Kottke   Oct 01, 2014

Every year, evolutionary biologist and professor David Barash gives his students The Talk about how evolution and religion do and do not get along.

It’s irresponsible to teach biology without evolution, and yet many students worry about reconciling their beliefs with evolutionary science. Just as many Americans don’t grasp the fact that evolution is not merely a “theory,” but the underpinning of all biological science, a substantial minority of my students are troubled to discover that their beliefs conflict with the course material.

Until recently, I had pretty much ignored such discomfort, assuming that it was their problem, not mine. Teaching biology without evolution would be like teaching chemistry without molecules, or physics without mass and energy. But instead of students’ growing more comfortable with the tension between evolution and religion over time, the opposite seems to have happened. Thus, The Talk.

This is the sort of thing Barash talks about:

The more we know of evolution, the more unavoidable is the conclusion that living things, including human beings, are produced by a natural, totally amoral process, with no indication of a benevolent, controlling creator.

(via @TomJunod)

A Disappearing Planet

posted by Jason Kottke   Jul 15, 2014

From ProPublica, an alarming series of graphs and charts on animal extinction: A Disappearing Planet.

Animal species are going extinct anywhere from 100 to 1,000 times the rates that would be expected under natural conditions. According to Elizabeth Kolbert’s The Sixth Extinction and other recent studies, the increase results from a variety of human-caused effects including climate change, habitat destruction, and species displacement. Today’s extinction rates rival those during the mass extinction event that wiped out the dinosaurs 65 million years ago.

(via @SrikarDR)

The leaf that hates water

posted by Jason Kottke   Jun 20, 2014

Aatish Bhatia noticed a plant in his backyard whose leaves naturally repelled water. He took a sample to a friend who had access to a high-speed camera and an electron microscope to investigate what made the leaves so hydrophobic.

But how does a leaf become superhydrophobic? The trick to this, Janine explained, is that the water isn’t really sitting on the surface. A superhydrophobic surface is a little like a bed of nails. The nails touch the water, but there are gaps in between them. So there’s fewer points of contact, which means the surface can’t tug on the water as much, and so the drop stays round.

The leaf is so water repellant that drops of water bounce right off of it:

Immigrant life on Mars

posted by Jason Kottke   May 20, 2014

If there wasn’t life on Mars before, there might be now. Before NASA sent Curiosity to Mars, it was thoroughly cleaned of all traces of contaminants. But swabs of rover’s surfaces taken before it was sent to Mars have revealed 377 different strains of bacteria that potentially could have made the trip. Some of them may have even survived.

A study that identified 377 strains found that a surprising number resist extreme temperatures and damage caused by ultraviolet-C radiation, the most potentially harmful type. The results, presented today at the annual meeting of the American Society for Microbiology, are a first step towards elucidating how certain bacteria might survive decontamination and space flight.

The anternet

posted by Jason Kottke   Apr 04, 2014

Researchers at Stanford have observed that foraging harvester ants act like TCP/IP packets, so much so that they’re calling the ants’ behavior “the anternet”.

Transmission Control Protocol, or TCP, is an algorithm that manages data congestion on the Internet, and as such was integral in allowing the early web to scale up from a few dozen nodes to the billions in use today. Here’s how it works: As a source, A, transfers a file to a destination, B, the file is broken into numbered packets. When B receives each packet, it sends an acknowledgment, or an ack, to A, that the packet arrived.

This feedback loop allows TCP to run congestion avoidance: If acks return at a slower rate than the data was sent out, that indicates that there is little bandwidth available, and the source throttles data transmission down accordingly. If acks return quickly, the source boosts its transmission speed. The process determines how much bandwidth is available and throttles data transmission accordingly.

It turns out that harvester ants (Pogonomyrmex barbatus) behave nearly the same way when searching for food. Gordon has found that the rate at which harvester ants — which forage for seeds as individuals — leave the nest to search for food corresponds to food availability.

A forager won’t return to the nest until it finds food. If seeds are plentiful, foragers return faster, and more ants leave the nest to forage. If, however, ants begin returning empty handed, the search is slowed, and perhaps called off.

(via wordspy)

Neil deGrasse Tyson explains evolution

posted by Jason Kottke   Mar 23, 2014

The reboot of Cosmos has been solid but not spectacular so far, but the second episode contains as solid and clear an explanation of evolution as I’ve ever seen.

Even if evolution clashes with your world view, this is worth watching if only to understand what you’re aligned against (per Bret Victor’s advice). The third episode airs on Fox tonight and is about the creation of the scientific method.

There are lots of fish in the sea

posted by Jason Kottke   Mar 05, 2014

A group of marine biologists that has been recently studying mesopelagic fish (“fish that live between 100 and 1000m below the surface”) believes that 95% of fish biomass is unknown to humans. Marine dark matter. The problem lies with how fish have traditionally been counted and the enhanced visual and pressure senses of these fish.

He says most mesopelagic species tend to feed near the surface at night, and move to deeper layers in the daytime to avoid birds.

They have large eyes to see in the dim light, and also enhanced pressure-sensitivity.

“They are able to detect nets from at least five metres and avoid them,” he says.

“Because the fish are very skilled at avoiding nets, every previous attempt to quantify them in terms of biomass that fishing nets have delivered are very low estimates.

“So instead of different nets what we used were acoustics… sonar and echo sounders.”

A not-so-difficult prediction to make is that humans will find a way to catch these wary creatures, we’ll eat most of them, and then we’ll be back to where we are now: the world’s oceans running low on fish. (via @daveg)

Plant intelligence

posted by Jason Kottke   Dec 17, 2013

Plants eat light, grow almost everywhere on Earth, and make up 99% of the planet’s biomass. But do what extent do plants think? Or feel? Michael Pollan tackles the question of plant intelligence in a thought-provoking article for the New Yorker (sadly behind their paywall).

Indeed, many of the most impressive capabilities of plants can be traced to their unique existential predicament as beings rooted to the ground and therefore unable to pick up and move when they need something or when conditions turn unfavorable. The “sessile life style” as plant biologists term it, calls for an extensive and nuanced understanding of one’s immediate environment, since the plant has to find everything it needs, and has to defend itself, while remaining fixed in place. A highly developed sensory apparatus is required to locate food and identify threats. Plants have evolved between fifteen and twenty different senses, including analogues of our five: smell and taste (they sense and respond to chemicals in the air or on their bodies); sight (they react differently to various wavelengths of light as well as to shadow); touch (a vine or root “knows” when it encounters a solid object); and, it has been discovered, sound.

In a recent experiment, Heidi Appel, a chemical ecologist at the University of Missouri, found that, when she played a recording of a caterpillar chomping a leaf for a plant that hadn’t been touched, the sound primed the the plant’s genetic machinery to produce defense chemicals. Another experiment, dome in Mancuso’s lab and not yet published, found that plant roots would seek out a buried pipe through which water was flowing even if the exterior of the pipe was dry, which suggested that plants somehow “hear” the sound of flowing water.

One of the researchers featured in the article, Stefano Mancuso, has a TED talk available in which he outlines his case for plant intelligence:

The article also discusses if plants have feelings. If so, should we feel bad that our wifi routers might kill plants?

Update: Mancuso and Alessandra Viola have collaborated on a new book about the intelligence of plants, Brilliant Green: The Surprising History and Science of Plant Intelligence.

Dog breed “improvement”

posted by Jason Kottke   Dec 04, 2013

From a blog about the science of dogs, a comparison of photos of purebred dogs from 1915 to those of today. You can see how much the dogs have changed in just under 100 years, in some cases for the worse. For instance, the difference in the Bull Terrier (aka the Spuds MacKenzie dog) is marked and a bit disturbing:

Bull Terrier

Pure breeding has also introduced medical problems for some breeds.

The English bulldog has come to symbolize all that is wrong with the dog fancy and not without good reason; they suffer from almost every possible disease. A 2004 survey by the Kennel Club found that they die at the median age of 6.25 years (n=180). There really is no such thing as a healthy bulldog. The bulldog’s monstrous proportions makes them virtually incapable of mating or birthing without medical intervention.

(via @mulegirl)

Iconic insects are disappearing

posted by Jason Kottke   Nov 25, 2013

The monarchs are late. Usually by the 1st of November, the forests of central Mexico are swarming with them. Last year, they came in record low numbers, only 60 million. This year? A week late and only 3 million. And this happening to insects across the spectrum.

A big part of it is the way the United States farms. As the price of corn has soared in recent years, driven by federal subsidies for biofuels, farmers have expanded their fields. That has meant plowing every scrap of earth that can grow a corn plant, including millions of acres of land once reserved in a federal program for conservation purposes.

Another major cause is farming with Roundup, a herbicide that kills virtually all plants except crops that are genetically modified to survive it.

As a result, millions of acres of native plants, especially milkweed, an important source of nectar for many species, and vital for monarch butterfly larvae, have been wiped out. One study showed that Iowa has lost almost 60 percent of its milkweed, and another found 90 percent was gone. “The agricultural landscape has been sterilized,” said Dr. Brower.

The Human Body

posted by Jason Kottke   Aug 16, 2013

My friends at Tinybop have released their first app, The Human Body, in which “curious kids ages 4+ can see what we’re made of and how we work, from the beating heart to gurgling guts”. Kelli Anderson did the illustrations for the app and they look amazing. Can’t wait to try this out with Ollie and Minna.

The trees of Chernobyl

posted by Jason Kottke   Aug 09, 2013

This is what the trees look like near Chernobyl when you cut them down. It’s a biiiit tricky but see if you can spot when the nuclear plant disaster happened…

Chernobyl trees

Not surprisingly, researchers have found evidence that the radiation has affected the growth of trees near the accident site. From the paper:

Mean growth rate was severely depressed and more variable in 1987-1989 and several other subsequent years, following the nuclear accident in April 1986 compared to the situation before 1986. The higher frequency of years with poor growth after 1986 was not caused by elevated temperature, drought or their interactions with background radiation. Elevated temperatures suppressed individual growth rates in particular years. Finally, the negative effects of radioactive contaminants were particularly pronounced in smaller trees. These findings suggest that radiation has suppressed growth rates of pines in Chernobyl, and that radiation interacts with other environmental factors and phenotypic traits of plants to influence their growth trajectories in complex ways.

Liquid mammoth blood found

posted by Jason Kottke   May 29, 2013

A mammoth recently found in Siberia was so well preserved that when researchers were chipping it out of the ice, liquid blood flowed out.

Semyon Grigoriev, chairman of the university’s Museum of Mammoths and head of the expedition, said: “The fragments of muscle tissues, which we’ve found out of the body, have a natural red colour of fresh meat. The reason for such preservation is that the lower part of the body was underlying (sic) in pure ice, and the upper part was found in the middle of tundra. We found a trunk separately from the body, which is the worst-preserved part.”

The temperature was ten degrees celsius below zero when the mammoth was found, so the discovery of liquid blood was a shock. “It can be assumed that the blood of mammoths had some cryo-protective properties,” Grigoriev said. “The blood is very dark, it was found in ice cavities below the belly and when we broke these cavities with a pick, the blood came running out.”

More photos and information here. Bring on the mammoth clones, John Hammond. (via @carlzimmer)

Bees still dying at a fantastic rate

posted by Jason Kottke   Apr 01, 2013

Despite progress in recent years on causes and cures, colony collapse disorder has wreaked havoc on honeybee colonies across the country.

A mysterious malady that has been killing honeybees en masse for several years appears to have expanded drastically in the last year, commercial beekeepers say, wiping out 40 percent or even 50 percent of the hives needed to pollinate many of the nation’s fruits and vegetables.

Which is like, yeah, big whoop, it’s just bees, right? Except that:

The Agriculture Department says a quarter of the American diet, from apples to cherries to watermelons to onions, depends on pollination by honeybees.

Possible fossils found in meteorite fragments?

posted by Jason Kottke   Mar 11, 2013

Well, here’s something potentially interesting: researchers at Cardiff University think they have found fossils in meteorite fragments from Sri Lanka.

The most startling claims, however, are based on electron microscope images of structures within the stones (see above). Wallis and co say that one image shows a complex, thick-walled, carbon-rich microfossil about 100 micrometres across that bares similarities with a group of largely extinct marine dinoflagellate algae.

They say another image shows well-preserved flagella that are 2 micrometres in diameter and 100 micrometres long. By terrestrial standards, that’s extremely long and thin, which Wallis and co interpret as evidence of formation in a low-gravity, low-pressure environment.

Gotta take this with a massive grain of salt, but it will be interesting to see how this one plays out.

Update: One of the authors of this study holds some unusual views about life on Earth.

On May 24, 2003 The Lancet published a letter from Wickramasinghe, jointly signed by Milton Wainwright and Jayant Narlikar, in which they hypothesized that the virus that causes Severe Acute Respiratory Syndrome (SARS) could be extraterrestrial in origin and not originated from chickens.

Wickramasinghe and his mentor Fred Hoyle have also used their data to argue in favor of cosmic ancestry, and against evolution.

Like I said, big grain of salt. (thx, onno)

Does every species get a billion heartbeats per lifetime?

posted by Jason Kottke   Feb 08, 2013

There’s an assumption that because of the relationship between metabolic rates, volume, and surface area, animals get an average of one billion heartbeats out of their bodies before they expire. Turns out there’s some truth to it.

One Billion Heartbeats

As animals get bigger, from tiny shrew to huge blue whale, pulse rates slow down and life spans stretch out longer, conspiring so that the number of heartbeats during an average stay on Earth tends to be roughly the same, around a billion.

Mysteriously, these and a large variety of other phenomena change with body size according to a precise mathematical principle called “quarter-power scaling”.

It might seem that because a cat is a hundred times more massive than a mouse, its metabolic rate, the intensity with which it burns energy, would be a hundred times greater. After all, the cat has a hundred times more cells to feed.

But if this were so, the animal would quickly be consumed by a fit of spontaneous feline combustion, or at least a very bad fever. The reason: the surface area a creature uses to dissipate the heat of the metabolic fires does not grow as fast as its body mass.

To see this, consider a mouse as an approximation of a small sphere. As the sphere grows larger, to cat size, the surface area increases along two dimensions but the volume increases along three dimensions. The size of the biological radiator cannot possibly keep up with the size of the metabolic engine.

Humans and chickens are both outliers in this respect…they both live more than twice as long as their heart rates would indicate. Small dogs live about half as long.

Immortality lessons from the humble jellyfish

posted by Jason Kottke   Nov 28, 2012

Looking to live forever? You might want to take a close look at the immortal jellyfish. This death-defying creature ages, but researchers studying the jellyfish found that, instead of dying, it started “to age in reverse, growing younger and younger until it reached its earliest stage of development, at which point it began its life cycle anew.” (If beginning the life cycle anew means another trip through junior high, count me out.) From NYT Magazine: Can a Jellyfish Unlock the Secret of Immortality?

Some birds have a heads-up display compass

posted by Jason Kottke   Mar 15, 2012

Birds can detect the magnetic field of the Earth, which gives them an incredible sense of direction. Curiously, this sense of direction doesn’t work in darkness. This led scientists to discover that some birds can actually see the directions overlaid on their normal vision, like a heads-up display.

According to the new model, when a photon of light from the Sun is absorbed by a special molecule in the bird’s eye, it can cause an electron to be kicked from its normal state into an alternative location a few nanometres away. Until the electron eventually relaxes back, it creates an ‘electric dipole field’ which can augment the bird’s vision - for example altering colours or brightness.

Crucially, the alignment of the molecule compared to the Earth’s magnetic field controls the time it takes for the electron to relax back, and so controls the strength of the effect on the bird’s vision.

There are many such molecules spread throughout the eye, with different orientations. So from the patterns on top of its vision, and the change of these patterns as it moves its head, the bird learns about the direction of Earth’s magnetic field.

(via @daveg)

The human body’s microbial ecosystem

posted by Jason Kottke   Jan 27, 2012

In this transcript of a talk given to the attendees of the Joint Summits on Translational Science, Carl Zimmer highlights an important aspect of understanding the human body and how to treat its many maladies: the ecosystem of microbes.

The microbes in your body at this moment outnumber your cells by ten to one. And they come in a huge diversity of species — somewhere in the thousands, although no one has a precise count yet. By some estimates there are twenty million microbial genes in your body: about a thousand times more than the 20,000 protein-coding genes in the human genome. So the Human Genome Project was, at best, a nice start. If we really want to understand all the genes in the human body, we have a long way to go.

Now you could say “Who cares? They’re just wee animalcules.” Those wee animacules are worth caring about for many reasons. One of the most practical of those reasons is that they have a huge impact on our “own” health. Our collection of microbes-the microbiome-is like an extra organ of the human body. And while an organ like the heart has only one function, the microbiome has many.

When food comes into the gut, for example, microbes break some of them down using enzymes we lack. Sometimes the microbes and our own cells have an intimate volley, in which bacteria break down a molecule part way, our cells break it down some more, the bacteria break it down even more, and then finally we get something to eat.

Another thing that the microbiome does is manage the immune system. Certain species of resident bacteria, like Bacteroides fragilis, produce proteins that tamp down inflammation. When scientists rear mice that don’t have any germs at all, they have a very difficult time developing a normal immune system. The microbiome has to tutor the immune system in how to do its job properly. It also acts like an immune system of its own, fighting off invading microbes, and helping to heal wounds.

While the microbiome may be an important organ, it’s a peculiar one. It’s not one solid hunk of flesh. It’s an ecosystem, made up of thousands of interacting species.

Meet LUCA, our distant Earth-sized ancestor

posted by Jason Kottke   Nov 25, 2011

Here’s an interesting hypothesis: that all current life on Earth originated from a planet-wide super-organism named LUCA.

The latest results suggest LUCA was the result of early life’s fight to survive, attempts at which turned the ocean into a global genetic swap shop for hundreds of millions of years. Cells struggling to survive on their own exchanged useful parts with each other without competition — effectively creating a global mega-organism.

It was around 2.9 billion years ago that LUCA split into the three domains of life: the single-celled bacteria and archaea, and the more complex eukaryotes that gave rise to animals and plants (see timeline). It’s hard to know what happened before the split. Hardly any fossil evidence remains from this time, and any genes that date that far back are likely to have mutated beyond recognition.

(via @daveg)

Pruney fingers for better gripping

posted by Jason Kottke   Sep 13, 2011

You know how your hands and feet get all wrinkly when they’re immersed in water for a long time? There’s speculation the wrinkles might be an adaptation that allows for better gripping in wet conditions.

Now a paper in the journal Brain, Behavior and Evolution offers more evidence that wet wrinkles serve a purpose. Much like the tread on a tire, they improve traction.

In the study, an evolutionary neurobiologist and his co-authors examined 28 fingers wrinkled by water. They found that they all had the same pattern of unconnected channels diverging away from one another as they got more distant from the fingertips.

The wrinkles allow water to drain away as fingertips are pressed to wet surfaces, creating more contact and a better grip.

(via stellar)

Urban evolution in NYC

posted by Jason Kottke   Jul 26, 2011

Evolutionary biologists are increasingly studying organisms (like mice, fish, and bacteria) in urban areas like New York City to find out how they evolve to urban conditions.

Dr. Munshi-South and his colleagues have been analyzing the DNA of the mice. He’s been surprised to find that the populations of mice in each park are genetically distinct from the mice in others. “The amount of differences you see among populations of mice in the same borough is similar to what you’d see across the whole southeastern United States,” he said.

Leaf recognition software

posted by Jason Kottke   May 19, 2011

LeafSnap is a new iPhone app that uses facial recognition techniques to identify trees based on photos of their leaves.

Leafsnap contains beautiful high-resolution images of leaves, flowers, fruit, petiole, seeds, and bark. Leafsnap currently includes the trees of New York City and Washington, D.C., and will soon grow to include the trees of the entire continental United States.

Wow. Garden Design has more info. (thx, claire)

How babby’s fish face is formed

posted by Jason Kottke   May 10, 2011

Whoa, watch the video at the top of this article to see how the human face develops in the womb from an age of one-month to ten weeks. It all just comes together right at the end!

If you watch it closely, you will see that the human face is actually formed of three main sections which rotate and come together in an unborn foetus.

The way this happens only really makes sense when you realise that, strange though it may sound, we are actually descended from fish.

The early human embryo looks very similar to the embryo of any other mammal, bird or amphibian — all of which have evolved from fish.

Your eyes start out on the sides of your head, but then move to the middle.

The top lip along with the jaw and palate started life as gill-like structures on your neck. Your nostrils and the middle part of your lip come down from the top of your head.

There is no trace of a scar; the plates of tissue and muscle fuse seamlessly. But there is, however, a little remnant of all this activity in the middle of your top lip — your philtrum.

(via hypertext)

NASA study of arsenic-based life flawed?

posted by Jason Kottke   Dec 07, 2010

Carl Zimmer in Slate:

Redfield blogged a scathing attack on Saturday. Over the weekend, a few other scientists took to the Internet as well. Was this merely a case of a few isolated cranks? To find out, I reached out to a dozen experts on Monday. Almost unanimously, they think the NASA scientists have failed to make their case. “It would be really cool if such a bug existed,” said San Diego State University’s Forest Rohwer, a microbiologist who looks for new species of bacteria and viruses in coral reefs. But, he added, “none of the arguments are very convincing on their own.” That was about as positive as the critics could get. “This paper should not have been published,” said Shelley Copley of the University of Colorado.

(thx, anil)

Albino redwoods

posted by Jason Kottke   Dec 06, 2010

There may only be a few dozen albino redwoods in the world; they’re difficult to find so no one knows the real number. The albinos lack chlorophyll, making them unable to produce their own food, so they freeload off of a parent tree.

Albino redwood

KQED has a short video segment about the albino redwoods as well.

Discovered: a new form of life

posted by Jason Kottke   Dec 02, 2010

NASA’s astrobiology announcement is that they’ve found a new kind of life that incorporates the normally toxic arsenic into its DNA.

Life like us uses a handful of basic elements in the majority of its biochemistry: carbon, hydrogen, oxygen, and nitrogen for the most part. But phosphorus is also a critical element in two major ways: it’s used as the backbone of the long, spiral-shaped DNA and RNA molecules (think of it as the winding support structure for a spiral staircase and you’ll get the picture), and it’s part of the energy transport mechanism for cells in the form of ATP (adenosine triphosphate). Without it, our cells would literally not be able to reproduce, and we’d be dead anyway if it were gone. There are many other ways phosphorus is used as well, including in cell membranes, bones, and so on. It’s a key element for all forms of life.


Amazingly, using radioisotope-tagged molecules containing arsenic, they were able to find that the microbes incorporated the arsenic into their very DNA! It’s hard to stress how shocking this is; as I understand it, saying something like that to a microbiologist without evidence would’ve had them slowly backing away from you and looking for weapons or an escape route.

I guessed wrong about what NASA was set to announce today, but the actual announcement is much more interesting than the mere discovery of extraterrestrial life. Aliens are inevitable — we’re going to find them sooner or later — but a new kind of DNA, that’s not something that happens every day. Exciting! (thx, jon)

Has NASA discovered extraterrestrial life?

posted by Jason Kottke   Nov 29, 2010

Here’s a curious press release from NASA:

NASA will hold a news conference at 2 p.m. EST on Thursday, Dec. 2, to discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life. Astrobiology is the study of the origin, evolution, distribution and future of life in the universe.

I did a little research on the news conference participants and found:

1. Pamela Conrad (a geobiologist) was the primary author of a 2009 paper on geology and life on Mars

2. Felisa Wolfe-Simon (an oceanographer) has written extensively on photosynthesis using arsenic recently (she worked on the team mentioned in this article)

3. Steven Benner (a biologist) is on the “Titan Team” at the Jet Propulsion Laboratory; they’re looking at Titan (Saturn’s largest moon) as an early-Earth-like chemical environment. This is likely related to the Cassini mission.

4. James Elser (an ecologist) is involved with a NASA-funded astrobiology program called Follow the Elements, which emphasizes looking at the chemistry of environments where life evolves (and not just looking at water or carbon or oxygen).

So, if I had to guess at what NASA is going to reveal on Thursday, I’d say that they’ve discovered arsenic on Titan and maybe even detected chemical evidence of bacteria utilizing it for photosynthesis (by following the elements). Or something like that. (thx, sippey)

Update: According to Alexis Madrigal, the answer to the hyperbolic question in the headline is “no”.

I’m sad to quell some of the @kottke-induced excitement about possible extraterrestrial life. I’ve seen the Science paper. It’s not that.

Stem cells to aid the blind

posted by Jason Kottke   Nov 24, 2010

Clinical trials are about to begin where embryonic stem cells will be injected into the eyes of people with Stargardt’s macular degeneration.

Robert Lanza, the company’s chief scientific officer, said that the first patient could receive the stem cell transplants early in the new year and although the trial is designed primarily to assess safety, the first signs of visual improvement may be apparent within weeks. “Talking to the clinicians, we could see something in six weeks, that’s when we think we may see some improvements. It really depends on individual patients but that’s a reasonable time frame when something may start to happen,” Dr Lanza said.

On the merits of premature ejaculation

posted by Jason Kottke   Nov 19, 2010

Evolutionary speaking, premature ejaculation may not be such a bad thing after all.

So given these basic biological facts, and assuming that ejaculation is not so premature that it occurs prior to intromission and sperm cells find themselves awkwardly outside of a woman’s reproductive tract flopping about like fish out of water, what, exactly, is so “premature” about premature ejaculation? In fact, all else being equal, in the ancestral past, wouldn’t there likely have been some reproductive advantages to ejaculating as quickly as possible during intravaginal intercourse-such as, oh, I don’t know, inseminating as many females as possible in as short a time frame as possible? or allowing our ancestors to focus on other adaptive behaviors aside from sex? or perhaps, under surreptitious mating conditions, doing the deed quickly and expeditiously without causing a big scene?

Still, for recreational sex, it blows. (As it were.)