One of the norms in biology that we find over and over again is “not to evolve unless the physical or biological environment changes” and this norm is consistent with Darwin and his theories about evolution.
Researchers have found a microorganism that has not evolved in 2 billion years! In fact, it appears to be the oldest living organism on the planet. It is a deep sea organism and it was found by Paleobiologist William Schopf in mud off the coast of South America. Two billion years is about half the age of the earth.
The microorganisms found in the mud on the coast of South America are identical to others found in Western Australia. They confirm the hypothesis that organisms will not change (evolve) biologically unless there is a change in their physical environment. This notion is central to Darwin’s evolutionary theory.
Discovery of these organisms is to date the greatest absence of evolution. The organisms are sulfur bacteria microorganisms that are too small to see with the human eye and they are specifically 1.8 billion years old. Those found in Australia are preserved in rock and they look the same as bacteria dated at 2.3 billion years old and they look the same as sulfur bacteria today meaning they haven’t evolved. Modern sulfur bacteria was found in the mud off the coast of Chile.
Darwin focused more on species that had evolved more than he focused on species that had not evolved. Researchers believe the environment that these organisms live in has not changed for 3 billion years. If they had evolved then that would mean that our understanding of evolution is flawed because biological evidence tells us that organisms only evolve when their environment changes.
So what about humans? Humans evolved because our environment changed. Savannahs and grasslands formed as the result of environmental changes and our ancient human ancestors were basically forced out of the trees. In short, we evolved into no longer being arboreal creatures but ground dwelling creatures. And our environment is changing today so that means that human evolution is an ongoing process! What are we evolving into today? It’s uncertain at this point.
If you believe global warming is the issue then that means our climate is becoming drier and hotter and that might mean development of adaptations in our bodies to help us survive in such a changed climate. Body hair might become more sparse as our bodies will need more adaptations to keep ourselves cool. We could even become a nocturnal species (live at night, sleep in the day) in order to avoid the hotter temperatures. Some people are already adapting as they tend to be more nocturnal and have less body hair.
If you believe global cooling is the problem then as our climate becomes colder we’d expect to see some adaptations too such as the growth of more body hair. We’d also expect to see humans become shorter and stockier as such a body type is more conducive to cold climates. In fact, we already see these adaptations too in some regions.
So which is it? Global warming or global cooling?
That issue continues to be a matter of great debate. Some researchers think we should already be going into a new ice age but we’re not! Or so it appears that we are not. Other researchers thought by 2015 we’d being seeing major climate changes such as ice-less poles and no glaciers. But, Antarctica has more ice cover than ever while the Arctic seems to have less ice cover. If we were entering into a new ice age then certainly ice at both poles would be growing and glaciers would be expanding. But, in fact, glaciers are continuing to retreat and melt and sea levels are rising as well. Much of the evidence in support of both theories is conflicting and contradictory and, frankly, no one is quite sure what is going on other than WE KNOW the CLIMATE IS CHANGING on Planet Earth. And for humans that means EVOLUTION! We are still evolving and the question is “into what?”. We already see adaptations in other organisms and we are seeing adaptations in humans too. Adaptations occur over long periods of time so don’t expect to see a “new and improved human” right away LOL. Or….it could go the other way so don’t expect to see an “old and archaic” human either!
Keep in mind, without climate change there is no evolution. That seems to be the rule in biology and that is what Darwin’s theories support as well.