Prehistoric humans helped spread edible fruit species across Central and South America, even as they wiped out the megafauna that had done so previously. In the process, we maintained and even expanded the plants’ habitats, increased biodiversity, and engineered ecosystems on two continents. Today, these fruit species could be important in 21st-century efforts to diversify human diets, address food scarcity, and improve agricultural sustainability.
Fruiting plants have evolved a very solid strategy for getting their offspring out into the world. Animals eat the fruit, they drop the seeds, and the next generation of plants takes root, often quite a distance away from their parents. Before about 12,000 years ago, animals like the giant sloth, elephant-like mammals called gomphotheres, and native horses did most of the work of seed dispersal in Latin America.
When those animals died out around the end of the Pleistocene, many of the fruit species they’d helped spread found their ranges contracting. But as the early Holocene climate shifted toward warmer, wetter conditions, humans picked up the slack in a big way for some fruit species.
How picky eaters promote genetic diversity
All that human meddling generally increases the genetic diversity of the plants involved. Humans are picky eaters, so we tend to eat fruit that’s appealing in some way, whether because of taste, texture, appearance, amount of actual fruit compared to rind and seeds, or willingness to grow in the right places. Because we typically only drop seeds from fruits we eat, that choosiness gradually selects for different combinations of traits people want. The effect is even more noticeable in domesticated species, where pre-Columbian farmers deliberately bred plants for certain traits.
The result is a lot more diversity in human-modified species than in wild ones.
Scientists have designed a heat-insulating material made from wood that is both light and strong and made entirely from tiny, stripped-down wood fibers.
The so-called nanowood, described in the journal Science Advances, could one day be used to make more energy-efficient buildings. It's cheap and biodegradable, too.
"Nature is producing this kind of material," said senior author Liangbing Hu, a materials scientist and engineer at the University of Maryland in College Park.
Managing heat is a major issue in the cities we build. It's hard to keep heat indoors in the winter and keep it outdoors in the summer. The insulating materials currently in use are often very expensive to make, both in terms of money and of energy. They're not usually biodegradable and ultimately contribute to our growing landfills. So scientists have been trying to come up with cheaper, more environmentally friendly options.
Fields, streets and cities, but also forests planted in rank and file, and dead straight rivers: humans shape nature to better suit their purposes, and not only since the onset of industrialization. Such influences are well documented in the Amazonian rainforest. On the other hand, the influence of humans was debated in Central Africa where major interventions seem to have occurred there 2,600 years ago: Potsdam geoscientist Yannick Garcin and his team have published a report on their findings in the journal PNAS. The research team examined lake sediments in southern Cameroon to solve the riddle of the "rainforest crisis." They found that the drastic transformation of the rainforest ecosystem at this time wasn't a result of climatic change, it was humankind.
More than 20 years ago, the analysis of lake sediments from Lake Barombi in southern Cameroon showed that older sediment layers mainly contained tree pollen reflecting a dense forested environment. In contrast, the newer sediments contained a significant proportion of savannah pollen: the dense primitive forest quickly transformed into savannahs around 2,600 years ago, followed by an equally abrupt recovery of the forest approximately 600 years later. For a long time, the most probable cause of this sudden change, dubbed the "rainforest crisis," was thought to be climate change brought about by a decrease in precipitation amount and increase in precipitation seasonality. Despite some controversy, the origin of the rainforest crisis was thought to be settled.
By reconstructing both vegetation and climate change independently -- through stable isotope analysis of plant waxes, molecular fossils preserved in the sediment -- the team confirmed that there was a large change in vegetation during the rainforest crisis, but indicated that this was not accompanied by a change in precipitation. "The rainforest crisis is proven, but it cannot be explained by a climate change," says Garcin. "In fact, in over 460 archaeological finds in the region, we have found indications that humans triggered these changes in the ecosystem." Archaeological remains older than 3,000 years are rare in Central Africa. Around 2,600 years ago, coincident with the rainforest crisis, the number of sites increased significantly, suggesting a rapid human population growth -- probably related to the expansion of the Bantu-speaking peoples in Central Africa. This period also saw the emergence of pearl millet cultivation, oil palm use, and iron metallurgy in the region.
My take on the thread linked to above... https://permies.com/t/75760/imagine-planted-massive-food-forests
was that it was about planting trees, planting quality trees, gleaning fruit from trees planted in urban areas and neighborhoods...I didn't see where anyone was talking about surviving on those trees, just that it would be a good thing for people and the planet. I reread kind of fast so probably missed something?
I probably agree that trying to 'survive' unprepared in the woods is not a good idea, although for awhile in my early twenties that's exactly what I thought I was doing (and yes it's a great weight loss program) and for sure it depends on the 'forest' itself. I think there is a thread here discussing *hypothetical* nomadic living.
I always wondered about the 'bug out' thing too though. I don't' think there's many places to go in the US anyway, ability to survive aside. Better to do our best where ever we're at I think.