Monthly Archives: February 2017

February 13, 2017 by Todd B. Bates A paramecium, one of the protozoans used in the Rutgers evolution and invasions experiment. Credit: Peter J. Morin

Biological invasions pose major threats to biodiversity, but little is known about how evolution might alter their impacts over time.

Now, Rutgers University scientists have performed the first study of how evolution unfolds after invasions change native systems.

The experimental invasionselaborate experiments designed by doctoral student Cara A. Faillace and her adviser, Professor Peter J. Morintook place in glass jars suitable for savory jam or jelly, with thousands of microscopic organisms on each side. After entering the jarsuncharted territory - the invaders won some battles and lost some against the "natives."

"Oftentimes, we know the initial impacts of invasive species but we don't know the long-term impactsif things will get better or worse," said Morin, a distinguished professor in the Department of Ecology, Evolution & Natural Resources in the School of Environmental and Biological Sciences. "Cara found that both things can happen, and it will depend a lot on the details of the biology of the species that's introduced and the biology of the community that's invaded."

The Rutgers scientists coauthored a study"Evolution Alters the Consequences of Invasions in Experimental Communities"that was published recently in Nature Ecology & Evolution.

Typically, biological invasions unfold when humans introduce exotic species - either accidentally or on purpose - into areas where they are not native, Faillace said. Invasive species, a subset of exotic species, usually are ecologically or economically harmful.

"Invasions can cause extinctions and that's been documented globally," she said. "They can also reduce diversity through competition, predation and when they introduce a pathogen."

In their study, the Rutgers researchers compared the performance of populations of resident and invading species before and after they interacted, and potentially evolved, for about 200 to 400 generations. They used two different groups of resident species consisting of aquatic bacteria, ciliates - protozoans with hair-like projections called ciliaand rotifers, organisms with cilia-laced mouths and retractable feet. The ciliates and rotifers were collected from Bamboo Pond in Rutgers Gardens in New Brunswick.

For the nearly two-year experiments, one species from each group was designated as an invader of the other community. One group had five ciliates and a rotifer. The other group had three different ciliates and a different rotifer.

The organisms' worlds were loosely lidded 8.5-ounce jarsabout the size of a jelly jar. The jars contained food, vitamins, sterile water and two sterile wheat seeds for extra nutrients.

There were likely hundreds of thousands of protozoans in a microcosm, or jar, and populations turned over fairly quickly, with many chances for mutations, Morin said.

"Every time an individual divides, it's still alive and it takes six to 24 hours for most of these organisms to reproduce," he said.

The study's results showed that the microbes' interactions altered the performance of the resident and invading species, and the researchers think evolution led to differences in performance.

A couple of species were abundant in the beginning but went extinct (they could not be found in the jar) after being invaded, Faillace added.

In nature, most biological invasions are accidental, Morin said.

"It took several tries to get the European starling in North America established, and that was intentional," he said. "Now they're the bane of every native bird."

"Gypsy moths were brought to North America by someone who wanted to see if they could establish a silk industry using gypsy moths," Morin said. "The cage they were kept in was damaged, they were released and the rest is history."

Yet many organisms, such as the emerald ash borer, which kills ash trees, get introduced accidentally through commerce, Faillace said. They include the Asian longhorned beetle, which also attacks and kills trees and likely arrived in shipping containers or pallets.

Biological invasions are especially damaging when a predator or pathogen is introduced and when native species have never encountered a predator, the scientists said.

Climate change is a major factor in biological invasions and its impact is likely increasing, Faillace said.

"Presumably as climate shifts, the species that can invade will change or the ranges of species that have invaded will change," she said.

"The bottom line is that we should expect to see changes in the impacts of invasive species as invaders and native species evolve over time," Morin said.

Explore further: Predator or not? Invasive snails hide even when they don't know

More information: Cara A. Faillace et al, Evolution alters the consequences of invasions in experimental communities, Nature Ecology & Evolution (2016). DOI: 10.1038/s41559-016-0013

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Biological invasions get less prime-time coverage than natural disasters, but may be more economically damaging and warrant corresponding investments in preparedness and response planning, according to three biologists writing ...

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Biological invasions pose major threats to biodiversity, but little is known about how evolution might alter their impacts over time.

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How evolution alters biological invasions - Phys.Org

February 13, 2017 by Luke Dunning, The Conversation Credit: Shutterstock

For 600m years, life has been responding to our changing world. Virtually every conceivable environment in every corner of the planet has been occupied as animals and plants have diversified. Environmental shifts and mass extinctions produce new evolutionary opportunities for organisms to exploit as they compete for survival.

But how do organisms grasp these opportunities? Do they evolve new traits in response to the pressures of new environments, or are they able to move into new habitats because they have already evolved the right adaptations? Much of evolutionary study rests on the the former idea being right. Yet a new study of the development of horses is the latest in a growing body of research that suggests the answer to this chicken-egg situation may be more complicated.

The chances of an organism's survival in a new habitat are governed by the area's biological and environmental conditions and whether these are compatible with the organism's basic requirements (its ecological niche). If they are compatible, the organism may be able to persist, adapt and thrive. The more specialised an organism's ecological niche, the harder it may be to move into a new environment.

For example, the caterpillars of the monarch butterfly feed almost exclusively on milkweed. It's hard to imagine the caterpillars successfully colonising a new habitat that doesn't have this vital food source. Another point to consider is that just because an organism can survive in a new environment doesn't necessarily mean it will be able to get there. For example, it would be practically impossible for polar bears to naturally spread from the North Pole to Antarctica.

Much of our understanding of how organisms evolve new traits to occupy new environments and ecological niches comes from the study of adaptive radiations. An adaptive radiation is the evolutionary process by which organisms rapidly diverge from a common ancestor into multiple different forms. There are numerous charismatic examples documented, including: Darwin's finches on the Galapagos Islands, cichlid fish in the lakes of East Africa, and Anolis lizards on the Caribbean islands.

From this kind of research it has been shown that adaptive radiations are primarily driven by ecological opportunity, the chance for a species to thrive when its environmental circumstances change. Examples of these opportunities include filling a vacant niche after a mass extinction event when it has fewer competitors or predators, or taking advantage of a newly available resource.

As animals and plants exploit these ecological opportunities, we would expect them to go through rapid physical changes as they adapt to their new environments. The pace of change would then slow over time as the opportunities run out. This prediction has formed the basis of much of evolutionary research, although studies are beginning to question the validity of our assumptions.

Horse history

The evolution of horses is remarkably well documented in the fossil record and is a textbook example of how evolutionary success is linked to trait evolution. Over the past 50m years, horses have evolved from dog-sized forest dwellers into the modern animals we know.

Along the way they have accumulated numerous environmental advantages, such as teeth adapted for grazing and modified hooves for speed. Although there are only seven species from this adaptive radiation alive today (the horse, donkey, plains zebra, mountain zebra, Grvy's zebra, kiang, and onager), fossils of hundreds of extinct species have been unearthed.

Now a new study published in Science has looked at the last 18m years of horse evolution to ask whether the origin of new horse species was linked with rapid physical changes. As you would expect, horse evolution has seen bursts of diversification when there have been new ecological opportunities. These opportunities included increased food availability, which meant larger and more varied populations of horses could be sustained.

Another ecological opportunity horses exploited was being able to migrate from America to Siberia across the Bering land bridge. From there they were able to colonise Europe, Asia, North Africa and the Middle East.

But the fossil record shows these bursts of horse diversification didn't follow the rapid evolution of new physical traits such as body size and teeth shape. Horses didn't need to change to be able to colonise the Old World, presumably because they were already adapted to similar grassland habitats in America.

The physical features that distinguish modern horse species in different locations evolved later. They are likely to be a result of short-term responses to extreme environmental conditions and shifts in resource availability.

The results of this latest study not only increase our understanding of the evolutionary history of one of the most successful lineages of mammals on earth, but also adds to our broader knowledge of when and why organisms adapt to their environment. When it comes to evolution's "which comes first?" question, the answer is probably both.

Explore further: Climate change responsible for rapid expansion of horse species over last 20 million years

This article was originally published on The Conversation. Read the original article.

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How the horse can help us answer one of evolution's biggest questions - Phys.Org

GIF

The Academy Awards are almost here and many people will be talking about red carpet fashion, comedic monologues, and who got robbed. But few will be paying attention to the most important awards categoryBest Visual Effects. This supercut pulls together all the past winners into a nice little reminder of how much has changed in the field, and how much visual effects changed the way movies are made.

Technically, the Oscar for Best Visual Effects has only been around since 1963. Before that, there was a category for Best Special Effects, an award that was shared by the visual and sound effects teams. But going back to the beginning of the Academy of Motion Picture Arts and Sciences, effects were recognized as a crucial part of filmmaking and in 1927, Wings received a special honor for Engineering Effects.

Along the way, thereve been a lot of no-brainer winners that set a new bar for effects like 2001: A Space Odyssey, Star Wars, and Jurassic Park. But there were also some surprising choices in there. Do you remember Innerspace? Id forgotten about it entirely but I think it was good. And can we talk about E.T. beating out Blade Runner? I love E.T. as much as anyone but I just dont see its effects as anywhere close to the Ridley Scott classic.

In two weeks, Deepwater Horizon, Doctor Strange, The Jungle Book, Kubo and the Two Strings, and Rogue One: A Star Wars Story will face off for the award. Until then, catch up on all the past winners below.

[Burger Fiction]

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See the Evolution of Movie Magic With Every Oscar Winner for ... - Gizmodo

Jason Cassella/Kingman Resident

In Blake Boggesss opinion piece that evolution is false he made several mistakes, assumptions, and plainly misinformed the public.

He says that evolution has never been observed. This is flat out false. There have been many cases where evolution has been observed in real time, including in species such as fish, moths, and foxes, to name but a few. But the most simple example: why do you think you have to get a different flu shot every year, or that there is a threat that antibiotics might not be as effective as they once were? Its because viruses and bacteria evolve; and we observe this in real time. You are entitled to your own opinions, but not to your own facts.

As far as the claim that scientists have not found the missing link, this is misconstrued. There have been many discoveries of intermediate species of human ancestors, over 29, and more are being discovered. The logic of even finding the missing link is outdated and fallacious. When one is found, it creates two more empty spaces around it. Think about it this way. If you lined up every human ancestor back to the divergence from the other apes (yes we are an ape; Homo sapiens means wise ape), 6 to 8 million years ago, you would be hard pressed to see an overt split from one species to another; its that gradual. Finding the missing link therefore, even if we found thousands, would mean that there would be an incalculable many more empty spots. It is a project of infinite regress.

As far as the unknown. Evolution doesnt have the answer for abiogenesis, or the beginning of life. It doesnt claim to. But it has proven that all of life on this planet related. We prove this genetically, through fossils, through observation, and more. The science is settled. Evolution is as much a theory as gravity: its a fact.

The argument that evolution is wrong because God created us is following just a few branches of Christianity (and other religions), mostly prominently Protestant Evangelical Christianity. But evolution is not incompatible with religion, exemplified by the Catholic churchs acceptance of the theory of evolution by natural selection. I personally know a Methodist preacher who is also an evolutionary biologist. The argument is partisan and doesnt hold.

Think of evolution this way: for thousands of years humans have bred animals and plants into various breeds and forms. Nature works the same way through natural selection, mutation, genetic drift, gene flow, death and sexual selection. Its actually a very simple and elegant idea. Its one of the very best ideas and discoveries of our species.

Just think of the beauty of it. Mountains of evidence shows that at several points there were different hominins living on the planet at the same time. Just imagine coming across different human species, and what that must have been like. And genetically we can even see that if you go back far enough, were related even to the tree in your front yard, much less jelly fish and elephants. Its amazing really. Life is wondrous.

Evolution is the cornerstone of not just all of biology but of other scientific disciplines as well, based on change over time. The science is settled, and those rare few scientists that disagree are a certain brand of Creationists, who ironically attempt to use evolution to prove intelligent design. Those who flat out refuse evolution are of one of a few sects of religion and have none or no pertinent scientific background.

As Neil deGrasse Tyson so very well said, Science is true whether you believe it or not.

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Community Viewpoint: Evolution, like gravity, is much more than theory it is a fact - Kdminer