Monthly Archives: February 2017

February 13, 2017 The deep sea has its fair share of quirky creatures equipped with odd features, and the cockeyed squid, sporting two different sized eyes, likely doesn'tstand out too much among other bottom ocean dwellers.

But scientists have never before been able to pinpoint a reason for its two vastly different eyes. But now, researchers from Duke University may have finally nailed down an answer, according to a study published Monday in the journal Philosophical Transactions of the Royal Society B.

The cockeyed squid, officially known as Histioteuthis heteropsis, has long puzzled researchers. While the species is born with eyes of the same size, its left eye grows rapidly, becoming tube-shaped and sometimes twice the size of its right eye.

"You can't look at one and not wonder what's going on with them," Duke University biologist and study co-author Kate Thomas said in a press release.

Researchers watched more than 150 videos of the squids swimming in the Monterey Submarine Canyon in Monterey Bay,Calif., which were recorded over the past three decades, observing as they swam in an unconventional upside-down position. While doing so, the squids larger, left eyes continuously looked up, while their smaller right eyes were fixed downward.

Observation and light simulations revealed that the large eye seems to search for shadows of different fish swimming overhead, while the small eye scans the ocean floor for signs of light emitted by other marine organisms.

While the left eye's field of vision picks up shadows from sun shining into the water, that's not an option for the downward-facing eye, scientists concluded. Instead, they detect bioluminescence, the kind of chemically-produced light that comes from living organisms such as fireflies or deep sea fish. That requires a different kind of eye structure than is needed for ambient light. Bigger isn't better when it comes to spotting glowing fish, the researchers found, but larger eyes are better at detecting sunlight.

So while the cockeyed squids design might look odd at first glance, it actually allows the squids to navigate their complex environment.

"The eye looking down really only can look for bioluminescence," Snke Johnsen, the study's senior author and a professor of biology at Duke University, said in a statement. "There is no way it is able to pick out shapes against the ambient light. And once it is looking for bioluminescence, it doesn't really need to be particularly big, so it can actually shrivel up a little bit over generations. But the eye looking up actually does benefit from getting a bit bigger."

Overall, squid species are faring well among their deep sea neighbors. A 2016 study revealed that squid numbers have continuously boomed for six decades, while climate change and warming waters have spelled trouble for some other species.

While that marks good news for cephalopods for now, some wonder what long-term implications for aquatic life the trend could have particularly for the creatures they eat.

"We're seeing a new world here, one we haven't seen before. Any time you push an ecosystem into a different state, there's greater uncertainty in how it will behave, and how it will respond to future changes. Frankly, I think that should make people really worried," Ben Halpern, a biology professor at the University of California, Santa Barbara's Bren School of Environmental Science and Management and the director of the school's Center for Marine Assessment and Planning, told The Christian Science Monitor last year.

"More squid and octopus to eat may seem like a good thing, and in the short run maybe it is. But I'm more worried about the long run," he said.

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How this cockeyed squid shines a light on deep sea evolution - Christian Science Monitor

February 14, 2017 by Alan Flurry A female burying beetle feeds her begging young. The parent and offspring are in a mouse carcass prepared by the parent as food. Credit: Allen Moore/UGA

University of Georgia researchers have confirmed that becoming a parent brings about more than just the obvious offspringit also rewires the parents' brain.

The study, published this month in Nature Communications, finds that the transition from a non-parenting state to a parenting state reflects differences in neuropeptides generally associated with mating, feeding, aggression and increased social tolerance.

Neuropeptides are small proteins that allow neurons in the brain to communicate with each other; they also influence behavior.

The team's research-tested on an insect, the burying beetle Nicrophorus vespilloides-provides a predictive framework for studying the genetics of parenting and social interactions.

The burying beetle is intimately involved in raising its children, including regurgitating food to its begging offspring.

"We tested the idea that we could predict the genetic pathways involved in parenting based on old predictions from ethologists in the 1960s and 1970s," said the study's lead author Allen Moore, Distinguished Research Professor and head of the department of genetics. "When [burying beetle] parents feed their babies, they are feeding others rather than themselves and so genes that influence food-seeking behavior are likely to be involved."

Behavioral scientists predicted that genetic changes occur over time to develop parenting in a species. Based on this hypothesis, Moore's team sequenced and assembled the genome of the burying beetle and measured the abundance of neuropeptides. They theorized that behaviors related to parenting stemmed from alterations in existing genes rather than the evolution of new ones.

By looking at parenting and non-parenting beetles, their tests indicated that neuropeptides changed in abundance during parenting.

"When new traits evolve, evolution tends to modify existing genetic pathways rather than create new genes," Moore said.

The research, Moore said, suggests that many of the genes influencing parenting will be the same across many species. The commonality among organisms will help researchers identify genetic pathways important to parenting.

"It is exciting science when you take a step toward predicting the genetic changes involved in a behavior as complicated as parental care," he said. "And it was pleasing to collaborate with colleagues in genetics and Complex Carbohydrate Research Center, which allowed us to apply techniques that wouldn't otherwise be available to test our ideas."

Explore further: Beetles provide clues about the genetic foundations of parenthood

More information: Christopher B. Cunningham et al. Ethological principles predict the neuropeptides co-opted to influence parenting, Nature Communications (2017). DOI: 10.1038/ncomms14225

A team of researchers including scientists from the University of Georgia has identified many of the genetic changes that take place in burying beetles as they assume the role of parent. Their findings, published recently ...

Research published today reveals for the first time that the different roles of mothers and fathers are influenced by genetics. The study, by the Universities of Exeter and Edinburgh, shows how variation in where males and ...

Scientists have presented the most conclusive evidence yet that genes play a significant role in parenting.

Yelling. Screaming. Slamming of doors. Sneaking out.

A new study has examined the interaction between coparenting and coercive parenting in predicting children's disruptive behaviour.

Toddlers' fussy eating habits are mainly the result of genetic influences rather than the result of poor parenting, according to new research led by scientists at UCL.

(Phys.org)A team of researchers at the Shanghai Institutes for Biological Sciences has found that rhesus monkeys can pass the mirror self-awareness test if they are first taught how mirrors work. In their paper published ...

University of Georgia researchers have confirmed that becoming a parent brings about more than just the obvious offspringit also rewires the parents' brain.

Male guppies pay a high cost for their sexual harassment of female guppies including much higher mortality rates a new study from Macquarie University has found.

Scientists at the University of Wrzburg have generated new insights into the intricate molecular underpinnings of ubiquitin signaling. Their results may provide new avenues for cancer therapy.

The protein that helps the sperm and egg fuse together in sexual reproduction can also fuse regular cells together. Recent findings by a team of biomedical researchers from the Technion-Israel Institute of Technology, Argentina, ...

Sardinia sits at a crossroads in the Mediterranean Sea, the second largest island next to Sicily. Surrounded by sparkling turquoise waters, this Mediterranean jewel lies northwest of the toe of the Italian peninsula boot, ...

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Geneticists track the evolution of parenting - Phys.Org

TUESDAY, FEB. 14, 2017, 5:30 A.M.

Darwins Demons, a video game created at the University of Idaho, uses mutating aliens to teach students about natural selection and evolution.

The game, which retails for $4.99, was released Monday by video game distributor Steam. The release was timed to follow International Darwin Day on Feb. 12, which honors Charles Darwin and his groundbreaking work on how organisms change over time through the natural selection of characteristics that allow them to compete, survive and reproduce.

In the arcade-style game, players defend their spaceships against hordes of ever-evolving aliens. The fittest aliens, who destroy the most spaceships, produce the most offspring.

The nastiest, meanest aliens have the most babies. They shoot more projectiles, fire faster and move down the screen more aggressively, said Barrie Robison, a professor in UIs Department of Biological Sciences.

Within a few generations, the aliens turn into formidable foes, with genetic adaptations designed to outwit the gamers individual style of play.

Darwins Demons is the work of Robison, computer science Professor Terence Soule and an interdisciplinary team of 20 UI students, who spent last summer working on the game.

The team pulled together students majoring in biology, computer science, art and design, business, English and theater to work on various aspects of developing and marketing Darwins Demons. A National Science Foundation grant for evolution studies helped pay for the project.

The idea for Darwins Demons began several years ago, when Robison and Soule were brainstorming ways to present concepts in evolutionary biology to students.

There is ample evidence that school kids play a lot of video games, Robison said. But we wanted to make a game first, instead of a lesson plan disguised in a game.

Darwins Demons is rated for kids ages 10 and up. While younger kids can play it, they probably wont understand the science concepts, some of which are sophisticated enough for college-age audiences.

The game is based on mathematical models of evolutionary biology. Evolution computation, a sub-field of artificial intelligence, allows the video game to adapt to solve increasingly difficult problems, Soule said.

The game responds in an intelligent way to a players strategy, he said.

So, even though players can beef up defenses and fortify their spaceships, the aliens eventually prevail.

Evolution always wins, Robison said. It doesnt matter what you do, the alien population adapts to your strategy.

Like other arcade-style video games, Darwins Demons players try to beat other players highest score.

Robison has the highest score so far. But after about 20 generations of evolution, the aliens take down his fleet of spaceships.

Darwins Demons debuted on Steam, which is the amazon.com of the video game world for hard-core players, Robison said. By the end of the week, the site should include a demo of the game.

Business students are looking for ways to market the game to a wider audience of science teachers and parents. And Soule hopes to have Darwins Demons available on Xbox Live within a couple of months.

Proceeds from sales of the game will help fund similar projects in the future. If sales take off in a big way, theres also the potential for students to earn royalties from their work.

We want to develop a sustainable video design studio, Robison said. Were hoping we can release an evolutionary game around Darwins birthday each year.

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Evolution always wins: University of Idaho video game uses mutating aliens to teach science concepts - The Spokesman-Review

Science Daily

How evolution alters biological invasions -- ScienceDaily Science Daily Biological invasions pose major threats to biodiversity, but little is known about how evolution might alter their impacts over time. Now, Rutgers University ... and more »

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How evolution alters biological invasions -- ScienceDaily - Science Daily

In a previous article I described how theories of innovation provide insight into the limits of natural selection. I will now apply those concepts to hypotheses regarding the evolution of the vertebrate eye, a subject that, since the time of Charles Darwin, has been near center of the debate over the creative power of natural selection. As Darwin himself stated in the Origin of Species:

He did, however, still believe it could evolve over numerous gradual increments.

Today, evolutionists propose several of the stages in what they believe to be a plausible evolutionary path. Science writer Carl Zimmer has outlined the standard story:

See Wikipedia for a chart illustrating "Major stages in the evolution of the eye."

To add weight to this narrative, two biologists created a computer simulation, demonstrating, in their view, the incremental evolution of an eye in fewer than 400,000 generations.

This often-repeated tale sounds impressive at first, but it is not unlike most supposed explanations of the evolution of complex features. It scores high on imagination and flare but low on empirical evidence and thoughtful analysis. It most certainly does not represent a "detailed hypothesis." Likewise, the simulation does an admirable job of describing how a mechanical eye could develop incrementally, but it is completely disconnected from biological reality. In particular, it ignores the details of how a real eye functions and how it forms developmentally. When these issues are examined, the story completely collapses.

To fully appreciate why that is so requires a basic understanding of developmental biology. During development, cells divide, migrate, and differentiate into a wide variety of types. Throughout this process, the cells send chemical signals to their neighbors, and these signals cause proteins known as transcription factors (TF) to bind to genes in regulatory regions, which control the corresponding genes' activity. The TFs bind to what are called transcription factor binding sites (TFBS), and the correct binding enables the genes to produce their proteins in the right cells at the right time in the right amount.

The evolution of additional components in the vertebrate eye requires that this network of intercellular signals, TFs, TFBS, chromatin remodeling, as well as many other details be dramatically altered, so that each developmental stage can progress correctly. For instance, the seemingly simple addition of a marginally focusing lens -- that is to say, a lens that directs slightly more light onto a retina -- requires a host of alterations:

Ectodermic tissue folds into a lens placode, which then forms a lens vesicle.

Cells in the lens vesicle differentiate into lens fibers, which elongate to produce the proper lens shape.

The lens fibers then undergo several key modifications, including tightly binding together, filling almost entirely with special refractive proteins called crystallins, developing special channels to receive nutrients, and destroying their organelles.

All of these steps must proceed with great precision to ensure the end product focuses light in an improved manner. The development of the lens in all vertebrates is very similar, and it even resembles that in other phyla. Therefore, the development of the first lens should have closely followed the steps outlined above with only minor differences, inconsequential to the basic argument.

The challenge to evolution is that, short of completion, most of these changes are disadvantageous. A lens that has not fully evolved through the third step noted above would either scatter light away from the retina or completely block it. Any initial mutations would then be lost, and the process would have to start again from scratch. In the context of fitness terrains, an organism lacking a lens resides near the top of a local peak. The steps required to gain a functional lens correspond to traveling downhill, crossing a vast canyon of visually impaired or blind intermediates, until eventually climbing back up a new peak corresponding to lens-enhanced vision.

Once an organism has a functional lens, natural selection could then potentially make gradual improvements. However, moving from a reasonably functional lens to one that produces a high-resolution image is rather complex. In particular, the refractive index (i.e., crystalline concentration) has to be adjusted throughout the lens to vary according to a precise mathematical relationship. A gradual decrease from the inside to the outside is needed to prevent spherical aberrations blurring the image.

Even more steps are required for the improved image to be properly interpreted:

Feedback circuitry must be added to allow the lens to automatically refocus on images at different distances.

The retina has to be completely reengineered to process high-resolution images, including the addition of circuits to enable edge and motion detection.

The neural networks in the brain have to be rewired to properly interpret the pre-processed high-resolution images from the retina.

Higher-level brain functions must be enabled to identify different objects, i.e., dangerous ones such as a shark, and properly respond to them.

Until steps 2 through 4 are completed, a high-resolution image would likely prove disadvantageous, since most of the light would be focused on fewer photoreceptors. In insolation, the alterations of perfecting the lens and those involved in step 1 would hinder the analysis of large-scale changes to the field of view, such as identifying the shadow of a predator. Natural selection would thus remove most of the initial mutations, and evolution of the eye would come to a halt.

The difference between blurry and high-resolution vision is well illustrated by the box jellyfish. It has several eyes around its body. Two have lenses, which can produce highly focused images. However, the focal point is past the retina, so the retinal images are blurry. An ability to focus more clearly than is actually useful seems to be an example of gratuitous design. Zoologist Dan Nilsson comments:

However, for the box jellyfish a high-resolution image would be disadvantageous, since its neurology is engineered to respond to such bulky features as the edge of a mangrove. Is this blurry vision the result of the jellyfish not having yet evolved high-resolution vision? No: its neural organization is radically different from that needed for the latter. As Nilsson comments, "Another, more likely, interpretation is that the eyes are 'purposely' under-focused."

"Purposeful"? Yes, it would seem so. The example illustrates that low-resolution vision is not at an inferior point on the same fitness peak as high-resolution vision. Instead, both systems reside near the peaks of separate mountains. For any species, upgrading to high-resolution vision requires massive reengineering in a single step. Such radical innovation, coordinated to achieve a distant goal, is only possible with intelligent design.

Photo: European bison, by Michael Gbler [CC BY 3.0], via Wikimedia Commons.

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Eye Evolution: A Closer Look - Discovery Institute