Wolves and Bunnies

“Population biology was a radical new field back in the early 20th century. Rather than just collecting statistics to describe animal populations, a few ambitious researchers like Alfred Lotka wanted to create basic mathematical models of things like predators and prey to predict the evolution of their linked populations. Predators (like wolves) eat prey (like bunnies) so they can make more wolf babies, thereby increasing the wolf population. Bunnies do a fine job of reproducing on their own, but if too many are eaten, their population numbers suffer. Today, population biologists, ecologists, and their compatriots use mathematical models to study everything from the spread of disease to the propagation of invasive species. The approach has even found its way to the study of human civilizations, including their collapse in places like Easter Island.

S7e4_highway_ruins

“We used these tools to build a simple model for the evolution of a civilization with its planet. In our approach, the exo-civilization’s population and the planetary environment are braided together by energy use and its consequences. The planet gives the civilization energy resources. The civilization consumes them to do the work of civilization building. As a civilization harvests more power from the planet, its capacities soar. That includes the ability to make and feed more babies. This link between available energy (in the form of food for simple organisms) and rising birth rates is fundamental to population biology. And for human civilization the steep rise we’ve seen in population is closely tied to fertilizer involving fossil-fuel use. So greater energy will, in the beginning, mean bigger populations. But there’s no free lunch from a planetary perspective. Using all that energy has to result in feedback on the planet. That’s what we earthlings are just starting to see with climate change. If global warming gets really nasty, everything from energy harvesting to food production is going to get severely stressed and our large human population won’t be sustainable. That’s why our exo-civilization models linked rising planetary impacts with population declines. It was all pretty straightforward, requiring no assumptions about alien economics, sociology, or any other science-fiction ideas.

“But to allow for some choice on the part of the exo-civilization we also included a basic switch describing how the civilization could respond to changing planetary conditions. For the sake of simplicity, we imagined that the planet had just two kinds of energy resources. One had a high planetary impact (like fossil fuels). The other had low impact (like solar energy). In some models we allowed the civilization to switch from to one to the other as things got bad.

“So, what did the model tell us? We saw three distinct kinds of civilizational histories. The first—and, alarmingly, most common—was what we called “the die-off.” As the civilization used energy, its numbers grew rapidly, but the use of the resource also pushed the planet away from the conditions the civilization grew up with. As the evolution of the civilization and planet continued, the population skyrocketed, blowing past the planet’s limits. The population, in other words, overshot the planet’s carrying capacity. Then came a big reduction in the civilization’s population until both the planet and the civilization reached a steady state. After that the population and the planet stopped changing. A sustainable planetary civilization was achieved, but at a high cost. In many of the models, we saw as much as 70 percent of the population perish before a steady state was reached. In reality, it’s not clear that a complex technological civilization like ours could survive such a catastrophe…”

Text: Adam Frank, How Do Aliens Solve Climate Change? The Atlantic 
Advertisements

“You’re talking about memories…”

“UCLA biologists report they have transferred a memory from one marine snail to another, creating an artificial memory, by injecting RNA from one to another. This research could lead to new ways to lessen the trauma of painful memories with RNA and to restore lost memories.

“I think in the not-too-distant future, we could potentially use RNA to ameliorate the effects of Alzheimer’s disease or post-traumatic stress disorder,” said David Glanzman, senior author of the study and a UCLA professor of integrative biology and physiology and of neurobiology. The team’s research is published May 14 in eNeuro, the online journal of the Society for Neuroscience.

19a

“RNA, or ribonucleic acid, has been widely known as a cellular messenger that makes proteins and carries out DNA’s instructions to other parts of the cell. It is now understood to have other important functions besides protein coding, including regulation of a variety of cellular processes involved in development and disease.

“The researchers gave mild electric shocks to the tails of a species of marine snail called Aplysia. The snails received five tail shocks, one every 20 minutes, and then five more 24 hours later. The shocks enhance the snail’s defensive withdrawal reflex, a response it displays for protection from potential harm. When the researchers subsequently tapped the snails, they found those that had been given the shocks displayed a defensive contraction that lasted an average of 50 seconds, a simple type of learning known as “sensitization.” Those that had not been given the shocks contracted for only about one second.

“The life scientists extracted RNA from the nervous systems of marine snails that received the tail shocks the day after the second series of shocks, and also from marine snails that did not receive any shocks. Then the RNA from the first (sensitized) group was injected into seven marine snails that had not received any shocks, and the RNA from the second group was injected into a control group of seven other snails that also had not received any shocks.

“Remarkably, the scientists found that the seven that received the RNA from snails that were given the shocks behaved as if they themselves had received the tail shocks: They displayed a defensive contraction that lasted an average of about 40 seconds.

“It’s as though we transferred the memory,” said Glanzman, who is also a member of UCLA’s Brain Research Institute.

“In the field of neuroscience, it has long been thought that memories are stored in synapses. (Each neuron has several thousand synapses.) Glanzman holds a different view, believing that memories are stored in the nucleus of neurons.

“If memories were stored at synapses, there is no way our experiment would have worked,” said Glanzman, who added that the marine snail is an excellent model for studying the brain and memory.”

Text: Biologists ‘transfer’ a memory between snails, University of California.

Pic: Paul Rumsey, Snail, 1988-93.

“Read and write the language of the brain…”

“The therapeutic potential for the device is exciting. From helping to restore sight to the blind, hearing to the deaf, to reinstating sensation in patients with peripheral nerve damage and helping amputees control prosthetic limbs.

“This has great potential for neural prostheses, since it has the precision needed for the brain to interpret the pattern of activation,” says Mardinly. “If you can read and write the language of the brain, you can speak to it in its own language and it can interpret the message much better.” Mardinly is already thinking beyond therapeutic uses, towards augmenting human experience: “This is one of the first steps in a long road to develop a technology that could be a virtual brain implant with additional senses or enhanced senses.”

220px-Doubleslit3Dspectrum

“We’re still a ways off before you can plan your next staycation at a 3D Shot themed resort and spa. As of now, the researchers are testing a prototype in the visual, touch and motor areas of mice brains.

“The mice are showing similar patterns of neural response correlating to sensory stimuli. The next step is training the mice so scientists can observe behavior changes that correspond to the stimulation. Studying behavioral cues is the best measure of success because you can’t ask a mouse if it’s experiencing the ripe, mushroomy taste of Limburger cheese as you flash holograms into its cortex.

“The researchers plan to scale-up the device’s capacity to interpret and create from a broader terrain of brain matter while scaling-down the device to make it portable enough to slip inside a backpack.

“They’re also working towards capturing neural patterns inside the brain with the goal of reproducing sensory experience and playing it back through holography.”

Text: Scientists Project Holograms Into The Brain To Create Experiences, Forbes.

Surface Trawls

“Publication of the garbage patch study coincided with a new report from Britain, Foresight Future of the Sea, that found plastic pollution in the ocean could triple by 2050 unless a “major response” is mounted to prevent plastic from reaching the ocean. The report declared plastic pollution to be one of the main environmental threats to the seas, along with sea-level rise and warming oceans.

“The study included two aerial surveys in October of 2016 that took 7,000 images, and 652 ocean surface trawls conducted in July, August, and September of 2015 by 18 vessels.

“The surface trawls also filled in the rest of the story.

Aixi-Terra-Espacial-Europea-ESA_1235286778_25523962_900x636

“Fifty plastic items collected had a readable production date: One from 1977, seven from the 1980s, 17 from the 1990s, 24 from the 2000s, and one from 2010. Researchers also found 386 objects with recognizable words or sentences in nine different languages.

“The writing on a third of the objects was Japanese and another third was Chinese. The country of production was readable on 41 objects, showing they were manufactured in 12 different nations.

“The study also concluded that plastic pollution is “increasing exponentially and at a faster rate than in surrounding waters.” Others are not as confident that the conclusion indicates a dramatic change in distribution of marine debris. Much of the world’s marine debris is believed to lie in the coastal regions, not in the middle of oceans.

“Leonard says he was impressed with the scope of the study. “It’s strong science,” he says. “But at the same time, in this field, the harder we look, the more plastic we find.”

Text: The Great Pacific Garbage Patch Isn’t What You Think it Is, National Geographic

“In the outside world…”

“In the outside world, the problem isn’t that plants are suddenly getting more light: It’s that for years, they’ve been getting more carbon dioxide. Plants rely on both light and carbon dioxide to grow. If shining more light results in faster-growing, less nutritious algae—junk-food algae whose ratio of sugar to nutrients was out of whack—then it seemed logical to assume that ramping up carbon dioxide might do the same. And it could also be playing out in plants all over the planet. What might that mean for the plants that people eat?

06062014soylentoceanographic

“What Loladze found is that scientists simply didn’t know. It was already well documented that CO2levels were rising in the atmosphere, but he was astonished at how little research had been done on how it affected the quality of the plants we eat. For the next 17 years, as he pursued his math career, Loladze scoured the scientific literature for any studies and data he could find. The results, as he collected them, all seemed to point in the same direction: The junk-food effect he had learned about in that Arizona lab also appeared to be occurring in fields and forests around the world. “Every leaf and every grass blade on earth makes more and more sugars as CO2 levels keep rising,” Loladze said. “We are witnessing the greatest injection of carbohydrates into the biosphere in human history―[an] injection that dilutes other nutrients in our food supply.”

“He published those findings just a few years ago, adding to the concerns of a small but increasingly worried group of researchers who are raising unsettling questions about the future of our food supply. Could carbon dioxide have an effect on human health we haven’t accounted for yet? The answer appears to be yes—and along the way, it has steered Loladze and other scientists, directly into some of the thorniest questions in their profession…”

Text: The Great Nutrient Collapse, Politico.

Pic: Soylent Green, 1973.

Archipelagos of the Anthropocene

“Imagine Charles Darwin aboard the Beagle, sailing the seas across to the Galapagos and writing in his note books about finch beak forms across the different islands.

“Now imagine pockets of parkland scattered across a city, separated by oceans of malls and high rises, troughs of highways and roads.

“The dragons of Brisbane live on islands — just like Darwin’s finches did.

“And, on those islands they’re in completely human-made ecosystems with leaf blowers, fertile garden beds and human-derived food, pesticides and mowers.

“And they’re in an environment with a completely different make up of plants, prey and predators than they’ve ever had to deal with in the natural arena.

“It is a pressure cooker for evolution.

journey lizard

“I call it the archipelagos of the Anthropocene — this idea that city parks within cities are acting as islands. And potentially we are observing evolutionary processes that Darwin witnessed throughout his voyage,” Dr Frere says.

“In fact, the populations in Brisbane city are extremely genetically different from one another. So much so, that it is to the extent of different human cultural backgrounds.

“For us, the first step to speciation is genetic differentiation. I can’t tell you it will lead to a speciation event. But I think we need to be on the lookout because we’re witnessing evolution as it’s occurring.

“They are almost moving from being an arboreal species to a land-based species.

“Dr Frere is studying the isolated dragon populations in Roma Street Parklands, City Botanic Gardens, South Bank and Mt Coot-tha Botanic Gardens in Brisbane.

“The dragons’ genetic differentiation within each site is manifested in physical characteristics — referred to as morphology.

“In Brisbane city, you have unique equal morphology, so that at every single park the dragons are slightly different morphologically from one another.”

“The Roma Street dragons are smaller, but have really big heads. The City Botanical Garden dragons are immense compared to eastern water dragons in the wild, but have smaller heads and shorter limbs.

“They are starting to move away from being water dragons, and starting to be something else.”

Text: These water dragons are ‘evolving at a pace we can witness, ABC News.

Pic: Journey to the Centre of the Earth, 1959.

No known historical precedent

It’s an event researchers say has “no known historical precedent” and it is still unfolding.

In the six years since a massive tsunami struck Japan, at least 289 species of animals have travelled to the US on huge rafts of pollution.

Thousands of non-native marine crustaceans, fish, molluscs and anemones continue to land on the US west coast on rafts of plastic, fibreglass and other debris that was washed out to sea in 2011.

According to a paper describing the phenomenon, published today in the journal Science, as many as 65 per cent of the species are not native to US waters.

Study co-author Professor Jim Carlton from Williams College in Massachusetts fears if any are able to colonise, there could be devastating consequences.

“The immediate concerns are the potential economic and environmental impacts of any given invasion, like the North Pacific sea star in Australia,” he said.

Objects ranging from barges and fishing vessels to plastic bags and buoys were washed out to sea in a “massive debris field” during the 2011 tsunami.

This deluge of flotsam was then sucked into the Pacific trash vortex — a gyre of circulating marine rubbish that brushes the coast of Japan and circulates clockwise around the North Pacific Ocean.

Each spring, as offshore currents pushing off the US coast ease, “spring pulses” of trash wash ashore on the west coast.

The scientists say it is unclear yet whether any animals arriving on the rafts have been able to successfully colonise.

“We are in the establishment window. The lag time between their arriving and becoming established and detected can be a while,” Professor Carlton said.

The paper’s authors make the case that massive coastal development and climate change are converging to completely reshape the way species are dispersed around the globe.

“If we advance the climate change models that argue that hurricanes and typhoons and other storms will be increasing in frequency and size, then we enter an era in the 21st century where larger and more frequent storms are for the first time interfacing with the densest populations and infrastructure that we’ve ever had on [our] coastlines,” Professor Carlton said.

Professor Steven Chown from Monash University says the research will, “change our view of the world”.

“Their research is amazing in actually documenting this pulse event, and then demonstrating that we might have to expect more such large-scale events given the huge increase in infrastructure globally along with, of course, increasingly extreme weather events,” he said.

Text: Nick Kalvert, Tsunami ‘mega-rafts’ of debris ship hundreds of animal species from Japan to US, ABC News