If evolution is a continuing why are we not changing into a better species.?

Answer 1

Evolution can also mean change in a species so that it is better suited for its environment. And contrary to what a couple of the other answerers have written, humans continue to face selection pressure that results in this sort of evolutionary change.

In fact, I read two reports today, from the meetings of the American Association of Physical Anthropologists, that documented recent evolution in humans.

1. Since we are all descended from dark skinned Africans, when did the light skin of Europeans arise?
Well, it turns out that it wasn't so long ago. Largely, the light skin is a result of changes in a gene called SLC24A5. Europeans mostly have a particular change in the gene that leads to lighter skin. This is selected for because it allows people to make enough vitamin D in their skin even in places like northern Europe that don't get much of the sunlight necessary to make the vitamin. By looking at the DNA sequence surrounding the gene, researchers now think that the mutation that caused light skin may have arisen only about 5,300 - 12,000 years ago. Because of the selective advantage the mutation generates in vitamin D synthesis, it spread rapidly through the early European population. (The lab of Michael Hammer, University of Arizona.)

2. How are women able to have healthy babies at really high altitudes even though there isn't much oxygen?
By studying the pregnant women in Tibetan villages, researchers have documented that the women who have the most surviving babies have a genetic ability to carry much more oxygen in their blood. One might expect that all humans have similar blood chemistries, but in the extreme environment of the high Himalayas, those who have a change in a gene regulating oxygen carrying capacity have a clear advantage and are being selected for in terms of successful reproduction. The genetics make it clear that this is an example of active ongoing Darwinian selection in people. (The lab of Cynthia Beall, Case Western Reserve University.)

Evolution is real, and it *is* continuing in Homo sapiens. To see it though, one needs to have the scientific training to understand it, and the tools to analyze the genetics involved. Even so, the evidence is all around us, all the time. These two reports are just what I chanced across today looking for something to read during lunch; if I was actively looking for articles about human evolution, I would find *all* my time taken up reading them.

Answer 2

Evolution doesn't guarantee a better species. It just says that species will change slowly over time given their environment. Look at the Dodo bird, evolution didn't help it much, did it? The time it takes for a species to undergo these changes isn't clear either. In fact, it doesn't guarantee that any changes will take place. With the amount of time that humans have been around, we are not due for any evolutionary changes yet.

Answer 3

1. Not enough time to recognize the change

2. Natural selection isn't occuring. Normally the strongest organisms of a generation live best and reproduce most efficiently so there is more of them. At the same time the weaker ones have trouble and don't end up surviving. when the population is full of these stronger ones then another springs up that is slightly mutated and is even stronger. then this stronger one reproduces and sooner or later the population has all the genes that made that first one stronger. Today, people who have more trouble going about daily activities do not die out. our society today can provide assistance to them so they live just as well as every one else. When they have children their children may have their genes that make living more difficult but they live on using todays medicine and technology. Then the difficulty genes mix in with the genes that make us stronger and the result is some one that can live well but not better.

Hopefully that wasn't too confusing : ]

Answer 4

That's not the way evolution works....it doesn't proceed along a path, but rather is a process of what has been called "chance and necessity". It all has to do with leaving more offspring....if smarter people always left more offspring, humans would evolve to be smarter (but I'm guessing that's not happening!). Evolution acts on variability in the interbreeding population and selects out those with unfavorable traits and favors the survival of young of those with favorable traits. That is all that counts. There is no "trend" towards humans getting bigger heads or longer arms or any such thing....it is only what factors in a parent for those parents that leave more offspring. Those genetic traits are then enhanced. For your question....what is it about "better species" that would result in those "better" folks leaving more offspring?

With today's distribution of food and modern medicine we are largely outside of pressure for evolutionary change.

In contrast, in pre-historic times there were actually multiple species of humans on earth at the same time (Neanderthals and us) that had been separate long enough (Europe...neanderthals, Africa...us) to evolve separate traits. But when they spread out and encountered each other, only modern humans survived. We haven't had a whole lot of evolutionary change since then. In fact, we haven't had a whole lot of change since whatever common ancestor we shared with modern chimps....we now share over 95 - 98% of their DNA!

Answer 5

Evolution occurs relatively slowly when there isn't a lot of stress on the organisms. As humans are surviving quite successfully already on Earth, a beneficial mutation is unlikely to give its owner a strong advantage over other humans (leading to natural selection). Actually, evolution IS going on, but just at an extremely slow pace. An example is sexual selection. It is very similar to natural selection, but is caused by organisms choosing a sexual partner. If everybody liked blue-eyed mates, more of the offspring would be blue-eyed. Sexual selection is going on all over the world--it is one of the factors contributing to the different physical characteristics in different nationalities. This is often caused by imprinting, the attraction of organisms to others similar to those they are associated with (like their family) (and there are some very interesting experiments about imprinting) but that is going slightly off topic. So evolution IS happening, but not very quickly because humans are not under enough stress to compete.

Answer 6

For evolution to take place, there must be traits that enhance the ability to reproduce and bring healthy children into adulthood. Traits such as a high IQ or being tall don't really affect how many children a person can raise in our modern world, so there's no pressure for these traits to become more prevalent.

If something *did* affect survival or reproduction rates, the species in that environment would evolve.

Answer 7

Evolution does not have goal and is not directional. Evolution, the change in allele frequency over time in a population, is happening now. Speciation would require the proper beneficial mutation coupled with the right selection pressure in that population for the process of natural selection to carry the population into greater, or lesser complexity.

Answer 8

First, the process is ongoing and very long term.

Also, in the last several hundred years, humans have taken action to circumvent the evolutionary process by defeating the "survival of the fittest" precept. We do not allow the weak or deformed or diseased or ignorant or even the foolish to be removed from the gene pool by natural selection as is done in the animal and plant kingdoms.

Hey, ask again in about 250,000 years.

Answer 9

Evolution takes years to process. If humans were to become a better race, we would be long gone. Along with advancements. we need intelligence. What I am trying to say is "survival of the fittest." Those who are better adapted will grow. You cannot change without knowing your surroundings. I'm not sure if this makes sense, but it sounded good before I started typing.

Answer 10

we are. todays generation is tall, stronger, and has a longer life expectancy than of previous generations. evolution is a slow process, that is why you don't see leaps and bound changes. not that long ago, within 100 years most people didn't live to be 50. abraham lincoln was concidered a freak being over six feet tall. today he would be average height on an nba team.