Has evolution in humans stopped now?Has evolution in humans stopped now?
We cannot truly know if the human species will evolve into something else. To answer this as well as we can, we must consider how evolution works and ask if it still affects people.
In nature, evolution works by selecting organisms that are most adapted to their surroundings. The most adapted organisms live to breed and pass down their genes. So we must ask if certain characteristics make some people better adapted than other people.
I, personally, cannot see this going on right now. There do not appear to be any characteristics that make some people more likely than others to live to be able to reproduce. People who are smarter or taller or faster or have longer necks do not seem to be better adapted to life than other people. Therefore, I do not see how evolutionary pressures could be working on human beings and I do not think evolution is continuing.
However, there are indications that human evolution is continuing even without this sort of evolutionary pressure. Some studies show that some types of women (typically ones who are a little overweight) have more children than ones who are not. This means that evolution could be occurring based on what characteristics make women fertile, not what characteristics allow them to live to childbearing age. In that case, evolution would be continuing. Please follow the link for an artice about this.
I have read reports that the human brain has been slowly shrinking over the ages -- since the early fossils of H. Sapiens -- for reasons undetermined, but speculation is that as we have achieved far greater control over our predators and competitors (practically eliminated, except for ourselves) and our material needs such as food, tools, land, etc., we have less need for such traits as extreme alertness, preparation for fight-or-flight, and so on. So the resources we use to implement these can be used for other things.
Some of the population at most risk for malaria has developed a mechanism for defeating the parasite; unfortunately, while it's effective, this adaptation can lead to sickle-cell anemia. The results are still being counted as to whether this trait will spread or eliminate itself.
Also, it appears that the ability to digest non-human milk (from cows, etc) appeared relatively recently in Europe, and many humans still can't drink this kind of milk. This trait is called lactose tolerance; lactose is an important nutrient in milk, and the non-human variety is apparently different enough to be useless unlesss you are lactose tolerant. This trait gives us access to an otherwise unavailable food souce.
Here's a link to a good article:
I would argue that evolution never stops, though scientific and medical technology may advance at some point to where we can stop most of it. The larger question for me is, given the population and climate trends of the Earth, how much longer will the human population be able to evolve as a viable species on Earth, along with the thousands of other species which human action affects?
I don't think evolution in any animal ever truly stops. As the environment around you changes you have to change and evolve in order to survive in your changing environment.
yes we are still evolving even if we are doing it slowly
Though humans now have made large improvements in medical care and can deal with many of the illnesses that would have lead to people dying earlier, the process of natural selection and evolution is still operating in humans. Recent studies conducted with genetic data collected from over 2000 women over a 60 year period has allowed scientists to study certain traits and by looking at the way they have varied they can infer that humans are still evolving. The results seen also indicate that the rate of change due to natural selection is the same as it is in other species which are not as intelligent as humans.
So, I guess the human species as we know it is changing gradually and we could expect a super human strain to develop in a few million years.
Because of the increased ability of humans to survive in any adverse environment, and change the natural environment, using highly developed technology, the chances that people with one type of characteristic will loose out in the competitive struggle for survival to others with different characteristics has substantially reduced. For example, the modern societies have provision to protect and care for people with severe physical and mental handicaps also.
However, though the extent of comparative edge of people with certain physical characteristics have reduced, these have not been eliminated completely. Further, now economical, social and political environments are also likely to have substantial influence on the process of evolution. For example, there are major differences in the birth rate and population growth rate among different communities. These difference are correlated to variables such as economic status and religion. Such differences in population growth, can definitely lead to people with certain characteristics becoming more common than others.
Also, in future, we are likely to experience another kind of evolution. In the past, people with any severe health problem died very early, including at birth itself. But now, with the aid of advanced medical help, people with major health problems including genetic defects are also able to live long, and have children. In this way, the human population of future is likely have much lower levels of health in respect of characteristics dependent on genes.
Finally, the process of evolution, in the past led to development of different variety of organism, including humans, in different regions.. However in future the same process of evolution will work in the opposite direction to reduce the regional variations among humans. With greater ability of people of all type of people to survive in all types of environments, and with greater mobility of people, there will be greater similarity in people of all regions of the world.
Thus, the evolution will continue, but the direction which the evolution takes will change.