The General Rule of Evolution
5/4/2021 - Facebook (g.f.s.)
James Wehner shared a link - https://www.businessinsider.com/pizzly-bears-polar-grizzly-hybrid-spread-due-to-climate-crisis-2021-4?fbclid=IwAR3fHywrJLdb_7Yd3uMXVxZ8u3AMM4kB0vt3SEBxM9_h8gR-RLj_BryXak4
“This was a new one to me. I have heard of ligers before (lion/tiger hybrids), but I had not heard of a polar bear/grizzly hybrid. And apparently the off spring bears can also procreate, so they are not "mules". Evolution at work creating a new species due to changes in environment?”
“This was a new one to me. I have heard of ligers before (lion/tiger hybrids), but I had not heard of a polar bear/grizzly hybrid. And apparently the off spring bears can also procreate, so they are not "mules". Evolution at work creating a new species due to changes in environment?”
The general rule of evolution is that species remain stable until an external stressor acts upon them, something like climate for instance.
Take our modern ice age for example, which began some 2.6 million years ago.
(note - the previous global ice age occurred about 260 million years ago, near the end of the Permian Period. That means throughout the entire Age of Dinosaurs, and most of the Age of Mammals, there was no polar ice on the planet. So in effect, it’s today’s cooling that’s the anomaly.
Researchers have discovered at least 20 interglacial warming episodes. What happened in those is what’s happening today: Glaciers start to melt and sea levels rise. Ranges of warmth loving species expand, while those who thrive in cooler climes shrink. Species that don’t adapt go extinct.
When Earth begins to cool again, it’s the reverse.
While we can stop pollution, clean up the environment, reduce resource depletion, and work to reign in runaway population growth, no one can stop “global warming” because it’s an entirely natural process. We should be preparing for the inevitable future, whose early tendrils are already upon us.
- - - - -
The primary driving force behind evolution and species radiation are extinction events, especially the major ones.
Climate and Extinction Events are my two primary areas of focus, as Associate Curator of Paleontology for the Natural History Society of Maryland. Most people know of the major events, but there are even more minor events, and they too have their effect.
Life is incredibly opportunistic and if an ecological void is created, it will be filled by new and evolved species.
For example after the “Great Dying,” though it took about 50 million years for the entire ecosystem to reach pre-extinction levels, it only took about 5 million years for animals at the top of the food chain to emerge.
With regard to hybrids and mutations, it will take time and numbers to see if a new species has indeed showed up.
Also, evolution is a branching tree rather then a straight line. New tendrils are always reaching out as time passes, going in multiple directions. Though the tree keeps growing, most will disappear within a million years or less.
https://en.wikipedia.org/wiki/List_of_extinction_events
Take our modern ice age for example, which began some 2.6 million years ago.
(note - the previous global ice age occurred about 260 million years ago, near the end of the Permian Period. That means throughout the entire Age of Dinosaurs, and most of the Age of Mammals, there was no polar ice on the planet. So in effect, it’s today’s cooling that’s the anomaly.
Researchers have discovered at least 20 interglacial warming episodes. What happened in those is what’s happening today: Glaciers start to melt and sea levels rise. Ranges of warmth loving species expand, while those who thrive in cooler climes shrink. Species that don’t adapt go extinct.
When Earth begins to cool again, it’s the reverse.
While we can stop pollution, clean up the environment, reduce resource depletion, and work to reign in runaway population growth, no one can stop “global warming” because it’s an entirely natural process. We should be preparing for the inevitable future, whose early tendrils are already upon us.
- - - - -
The primary driving force behind evolution and species radiation are extinction events, especially the major ones.
Climate and Extinction Events are my two primary areas of focus, as Associate Curator of Paleontology for the Natural History Society of Maryland. Most people know of the major events, but there are even more minor events, and they too have their effect.
Life is incredibly opportunistic and if an ecological void is created, it will be filled by new and evolved species.
For example after the “Great Dying,” though it took about 50 million years for the entire ecosystem to reach pre-extinction levels, it only took about 5 million years for animals at the top of the food chain to emerge.
With regard to hybrids and mutations, it will take time and numbers to see if a new species has indeed showed up.
Also, evolution is a branching tree rather then a straight line. New tendrils are always reaching out as time passes, going in multiple directions. Though the tree keeps growing, most will disappear within a million years or less.
https://en.wikipedia.org/wiki/List_of_extinction_events
“We often hear ‘humans evolved from chimps’ when people explain human evolution. This is untrue. The modern day chimpanzee is just that: modern. We could not have possibly evolved from a modern species, which diverged from the species that went on to be humans about 6 million years ago.
Evolution is a slow process."
"When humans diverged from chimps all that time ago, our ancestor would have been smaller, furrier, and probably didn't walk up right. But after millions and millions of years, generation after generation, our ancestors slowly became more human-like.”
"When we illustrate the relationship between humans are our closest living relatives, we use a phylogenetic tree. This tree shows when we split from the species whose line went on to become modern day species.”
http://anthropologyiselemental.ua.edu/osteology.html
Evolution is a slow process."
"When humans diverged from chimps all that time ago, our ancestor would have been smaller, furrier, and probably didn't walk up right. But after millions and millions of years, generation after generation, our ancestors slowly became more human-like.”
"When we illustrate the relationship between humans are our closest living relatives, we use a phylogenetic tree. This tree shows when we split from the species whose line went on to become modern day species.”
http://anthropologyiselemental.ua.edu/osteology.html
“We know about many ancient human (genus Homo) and human-like species that lived long ago, all of which share much more in common with modern Homo sapiens than they do with chimpanzees. These species--such as the famous Australopithecus afarensis ("Lucy"), Homo erectus, and Homo neanderthalensis--are referred to as hominins, a group to which we also belong. We are the sole living hominins; all other members of this group are extinct and may therefore be considered stem-group hominins because they are more closely related to us than they are to our closest living relative, the chimpanzee.”
https://www.digitalatlasofancientlife.org/learn/systematics/phylogenetics/trees-classification/
https://www.digitalatlasofancientlife.org/learn/systematics/phylogenetics/trees-classification/