Feb 3, 2019 06:55 PM
The Wild Experiment That Showed Evolution in Real Time
https://www.theatlantic.com/science/arch...nt/581521/
EXCERPT: . . . A young evolutionary biologist, Barrett had come to Nebraska’s Sand Hills with a grand plan. He would build large outdoor enclosures in areas with light or dark soil, and fill them with captured mice. Over time, he would see how these rodents adapted to the different landscapes—a deliberate, real-world test of natural selection, on a scale that biologists rarely attempt.
[...] When researchers study evolution through natural selection, they typically focus on just one part of it. The essence of the process is this: Some genes confer beneficial traits. Those traits make their owners more likely to survive and reproduce in a given environment. Over time, those genes and traits become more common. So researchers might, for example, find genes behind certain traits (such as striped coats). Or they might link certain traits to success in a given environment (such as longer-legged lizards in hurricane-hit islands). Beyond some experiments with lab-grown microbes, they have rarely connected all the dots together.
That’s what Barrett accomplished. With hundreds of mice and years of research, he and his colleagues were able to show and measure, in the real world, “the full process of evolution by natural selection,” says Hopi Hoekstra of Harvard University, who led the study. “It’s all in one.”
[...] As time passed, many of the mice fell prey to owls, but after three months, the team returned and recaptured the ones that were left. Sure enough, they found that, compared with the average founding rodents, the average survivors were noticeably lighter in the light-sand enclosures, and darker in the dark-soil ones. Through the deaths of the most conspicuous individuals, the survivors from two initially identical populations had shifted in different directions thanks to their different environments. “It’s intuitive that if you match your background, you’re more likely to survive,” Hoekstra says. “But that’s been a just-so story for years.” This experiment showed that it matters—a lot.
A simpler study could have stopped here, but the team went deeper. Team member Stefan Laurent sequenced a gene called Agouti, which has been linked to fur color, in all 481 of the mice. He found seven mutations that had become more common in the light enclosures, and rarer in the dark ones....
MORE: https://www.theatlantic.com/science/arch...nt/581521/
Should we farm octopus?
http://www.anthropocenemagazine.org/2019...m-octopus/
EXCERPT: We currently farm 550 aquatic species for food around the world, and octopus is about to become the newest addition to that list. But a concerned team of international researchers write that farming these cephalopods at industrial scales will dramatically intensify the environmental impact of aquaculture–and put us in ethical hot water, too.
Wily, territorial, and difficult to breed in captivity, octopus might seem like an unconventional choice for aquaculture. Yet a growing number of countries [...] are trying their hand at ‘ranching’ these animals [...] Japan, in particular, is making headway–promising that by next year it will successfully be producing fully-farmed, market-ready octopuses. But adding octopus to aquaculture’s repertoire will worsen its already strained environmental record, write the researchers in the journal Issues in Science and Technology.
Like conventional fish farming, farming octopus at high densities would produce large amounts of faecal waste that would escape into the surrounding environment, polluting it. The application of antibiotics to octopus pens [...] would similarly infect the sea or soil where octopus are farmed. Octopus are large animals, meaning that farming them would also require more space [...]
But perhaps the biggest threat that the researchers foresee is that octopus are carnivorous animals that would require vast amounts of feed, made from wild-caught ocean fish. Already, aquaculture uses up one-third of the global fish catch. [...] Thus, producing large quantities of farmed octopus would likely worsen global overfishing.
[...] Studies point to the impressive cognitive abilities of octopus, and their behavioural complexity. As relatively solitary animals, they are also often aggressive towards others in their vicinity. Conventional aquaculture–where animals are confined in crowded enclosures with little to occupy them–would be unsuitable for the needs of these animals [...] These factors would seem to thoroughly destroy the case for octopus farming, yet there are powerful financial incentives driving this trade....
MORE (details): http://www.anthropocenemagazine.org/2019...m-octopus/
https://www.theatlantic.com/science/arch...nt/581521/
EXCERPT: . . . A young evolutionary biologist, Barrett had come to Nebraska’s Sand Hills with a grand plan. He would build large outdoor enclosures in areas with light or dark soil, and fill them with captured mice. Over time, he would see how these rodents adapted to the different landscapes—a deliberate, real-world test of natural selection, on a scale that biologists rarely attempt.
[...] When researchers study evolution through natural selection, they typically focus on just one part of it. The essence of the process is this: Some genes confer beneficial traits. Those traits make their owners more likely to survive and reproduce in a given environment. Over time, those genes and traits become more common. So researchers might, for example, find genes behind certain traits (such as striped coats). Or they might link certain traits to success in a given environment (such as longer-legged lizards in hurricane-hit islands). Beyond some experiments with lab-grown microbes, they have rarely connected all the dots together.
That’s what Barrett accomplished. With hundreds of mice and years of research, he and his colleagues were able to show and measure, in the real world, “the full process of evolution by natural selection,” says Hopi Hoekstra of Harvard University, who led the study. “It’s all in one.”
[...] As time passed, many of the mice fell prey to owls, but after three months, the team returned and recaptured the ones that were left. Sure enough, they found that, compared with the average founding rodents, the average survivors were noticeably lighter in the light-sand enclosures, and darker in the dark-soil ones. Through the deaths of the most conspicuous individuals, the survivors from two initially identical populations had shifted in different directions thanks to their different environments. “It’s intuitive that if you match your background, you’re more likely to survive,” Hoekstra says. “But that’s been a just-so story for years.” This experiment showed that it matters—a lot.
A simpler study could have stopped here, but the team went deeper. Team member Stefan Laurent sequenced a gene called Agouti, which has been linked to fur color, in all 481 of the mice. He found seven mutations that had become more common in the light enclosures, and rarer in the dark ones....
MORE: https://www.theatlantic.com/science/arch...nt/581521/
Should we farm octopus?
http://www.anthropocenemagazine.org/2019...m-octopus/
EXCERPT: We currently farm 550 aquatic species for food around the world, and octopus is about to become the newest addition to that list. But a concerned team of international researchers write that farming these cephalopods at industrial scales will dramatically intensify the environmental impact of aquaculture–and put us in ethical hot water, too.
Wily, territorial, and difficult to breed in captivity, octopus might seem like an unconventional choice for aquaculture. Yet a growing number of countries [...] are trying their hand at ‘ranching’ these animals [...] Japan, in particular, is making headway–promising that by next year it will successfully be producing fully-farmed, market-ready octopuses. But adding octopus to aquaculture’s repertoire will worsen its already strained environmental record, write the researchers in the journal Issues in Science and Technology.
Like conventional fish farming, farming octopus at high densities would produce large amounts of faecal waste that would escape into the surrounding environment, polluting it. The application of antibiotics to octopus pens [...] would similarly infect the sea or soil where octopus are farmed. Octopus are large animals, meaning that farming them would also require more space [...]
But perhaps the biggest threat that the researchers foresee is that octopus are carnivorous animals that would require vast amounts of feed, made from wild-caught ocean fish. Already, aquaculture uses up one-third of the global fish catch. [...] Thus, producing large quantities of farmed octopus would likely worsen global overfishing.
[...] Studies point to the impressive cognitive abilities of octopus, and their behavioural complexity. As relatively solitary animals, they are also often aggressive towards others in their vicinity. Conventional aquaculture–where animals are confined in crowded enclosures with little to occupy them–would be unsuitable for the needs of these animals [...] These factors would seem to thoroughly destroy the case for octopus farming, yet there are powerful financial incentives driving this trade....
MORE (details): http://www.anthropocenemagazine.org/2019...m-octopus/