This is the geographic distribution of the modern (left) and fossil (right) larger herbivore communities analyzed in the paper.
Credit: Faith et. al., PNAS 2019
Posted on 10/07/2019 8:00:35 PM PDT by SunkenCiv
Because putting together the puzzle of millions-of-years-old ecosystems is a difficult task, many studies have reconstructed the environments by drawing analogies with present-day African ecosystems, such as the Serengeti. A study led by a University of Utah scientist calls into question such approaches and suggests that the vast majority of human evolution occurred in ecosystems unlike any found today...
To test for differences between modern and ancient environments, the researchers analyzed a dataset of more than 200 present-day African mammal communities and more than 100 fossil communities spanning the past 7 million years in eastern Africa, a time period encompassing all of human evolution. They found that prior to 700,000 years ago, mammal communities looked far different from those today. For example, fossil communities supported a greater diversity of megaherbivores, species over 2,000 pounds, such as elephants. Likewise, the dietary structure of fossil communities frequently departed from those seen today, with patterns of grass- and leaf-eating species fluctuating in abundance. Around 1 million years ago, fossil communities began transitioning to a more modern makeup, which the authors suggest is the likely the outcome of long-term grassland expansion coupled with arid climate pulses...
Eastern Africa is a boon for mammal fossils, making it an ideal region to piece together ancient ecosystems over the past 7 million years. With their extensive database of both ancient and modern mammal communities, the researchers focused on three traits: diet, body size, and digestive strategy. For all of these traits, they found that the makeup of ancient herbivore communities differed significantly from those of today. This is key, as herbivores directly shape the structure of ecosystems in ways that impact a wide variety of animal and plant species.
(Excerpt) Read more at eurekalert.org ...
This is the geographic distribution of the modern (left) and fossil (right) larger herbivore communities analyzed in the paper.
Credit: Faith et. al., PNAS 2019
For most of the last two million years, the now-submerged continental shelves were dry land, not covered with ice for the most part, and warmer. Just sayin'.
*Previous thread today.
Is there a conflict of theories?
Not a re-boot of the human species. Just a shock to the environment.
None, because of the different time frames. However, the role of impact in producing glaciation is not yet widely recognized, but I’m workin’ on it from the outside in. :^)
http://www.freerepublic.com/focus/chat/3784332/posts
I don't want to be nearby when Greta Thunberg hears about this.
I don't want to be nearby when Greta Thunberg hears about this.
Greta probably thinks a herbivore is something from LIttle Shop of Horrors. And she's never seen the movie because of the sexist title.
species over 2,000 pounds...
Hillaphant?
So, we ate the big animals first?
species over 2,000 pounds...
Hillaphant?
:)
Tell them to accept Impact Glaciation or we’ll unless a 1000 Greta Thornberg wannabees on them, but with more autism.
Really?
Of interest is that fact that 1 million years ago when the article says things began to change is also when the every 100,000 year Ice Age/warming pattern began. That ought to get some study.
so Climate Change has been going on for the last 5 million years at least?
Who would have guessed!
The herbivore fossil community in Ethiopia and Kenya looks like a perfectly traced line following the Great Rift Valley.
Is that meaningful or just a coincidence?
Noticed that as well. Water, water, everywere there is abundant life.
There was a reboot 12,800 years ago in the Pleistocene Period by a comet or asteroid hitting Africa that wiped out most life there.
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