As to how that could have happened, it's unclear. A likely possibility is the occurrence of a sudden event that caused large-scale environmental trauma and wiped out majority of the Earth's species.
"Viruses, ice ages, successful new competitors, loss of prey — all these may cause periods when the population of an animal drops sharply," explains Jesse Ausubel, director of the Program for the Human Environment.
Such times give rise to sweeping genetic changes across the planet, causing new species to appear. However, the last time such an occurrence took place was 65 million years ago, when an asteroid hit the Earth and killed off the dinosaurs and half of all other species on the planet.
When we present insects from Pennsylvania with plants that evolved on another continent, chances are those insects will be unable to eat them. We used to think this was good. Kill all insects before they eat our plants! But an insect that cannot eat part of a leaf cannot fulfill its role in the food web. We have planted Kousa dogwood, a species from China that supports no insect herbivores, instead of our native flowering dogwood (Cornus florida) that supports 117 species of moths and butterflies alone. In hundreds of thousands of acres we have planted goldenraintree from China instead of one of our beautiful oaks and lost the chance to grow 532 species of caterpillars, all of them nutritious bird food. My research has shown that alien ornamentals support 29 times less biodiversity than do native ornamentals.
Homeowners can do this by planting the borders of their properties with native trees plants such as white oaks (Quercus alba), black willows (Salix nigra), red maples (Acer rubrum), green ashes (Fraxinus pennsylvanica), black walnuts (Juglans nigra), river birches (Betula nigra) and shagbark hickories (Carya ovata), under-planted with woodies like serviceberry (Amelanchier canadensis), arrowwood (Viburnum dentatum), hazelnut (Corylus americnus), blueberries (Vaccinium spp) . Our studies have shown that even modest increases in the native plant cover on suburban properties significantly increases the number and species of breeding birds, including birds of conservation concern. As gardeners and stewards of our land, we have never been so empowered to help save biodiversity from extinction, and the need to do so has never been so great. All we need to do is plant native plants!
Landmark new research that involves analyzing millions of DNA barcodes has debunked much about what we know today about the evolution of species.
In a massive genetic study, senior research associate at the Program for the Human Environment at Rockefeller University Mark Stoeckle and University of Basel geneticist David Thaler discovered that virtually 90 percent of all animals on Earth appeared at right around the same time.
More specifically, they found out that 9 out of 10 animal species on the planet came to being at the same time as humans did some 100,000 to 200,000 years ago.
"This conclusion is very surprising," says Thaler, "and I fought against it as hard as I could."
He's not talking about what most people would consider diversity.
From just the first dozen minutes or so, he's essentially likening his experience in the military, which was a functioning multicultural community, in essence, with failed community in a permacultural context.
I don't know why he's phrased it the way he has, because his message is more along the lines of, "Gee, I wish everyone was on the same permacultural page as I am."
The problem I see is where he's on page, say, thirty-one, and I am on page three-sixty-one. Or vice versa, but you get the point.