Human Evolution: Not Complete?

our cranial capacity, on average, is smaller than neanderthal. most of his was taken up by his sense of smell.

Is no 'what if it isn't?' It isn't. Period. Evolution never stops.

Think our brains will be shrinking though (not very optimistic about our species.)

Depends Hes on how you define the word. In fact, something evolves until further evolution is to no significant advantage

Evolution never stops. It's going on right now; we are just less likely to notice it because our generations are fairly long.

Jes I'm not so sure. Having reached a climax, as with the Humanoid, depending on your def of the term, yes it might continue but in the wrong direction

Evolution doesn't have a positive 'end' to it. That's intelligent design thinking.

Evolution is just change.

Survival of the fittest has exactly two aims - make the being live long enough to reproduce, and then they must reproduce.

That's it.

Yet Jes usu thought of as change for the better:

▸ noun: a process in which something passes by degrees to a different stage (especially a more advanced or mature stage)

http://onelook.com/?w=Evolution&ls=a

So looks like we're headed downhill:

http://able2know.org/topic/289282-1

That would sure as hell explain President Bush!

And Gerald Ford, Rab, who it was said couldn't walk and chew gum at the same time

https://en.wikipedia.org/wiki/Gerald_Ford

That was Lyndon Johnson, and he said he couldn't fart and walk at the same time.

skulls from paleoindian sites have a collection of features that weve since adjusted away in our ongoing adaptation to the world as it is now.

Early deposits of habitation are now being identified on Coastal Plain areas that extend into the present day continental shelf. We had a whole area of habitation that was 3-400 ft lower in the US and actually presented a thousand km 2 (or more) in the area between UK and mainland Europe as a large inhabited coastal marsh and hummock zone (sorta like the back beach areas along the US Intercoastal Waterway)

Ill bet in those areas we will find many modifications that statistically will define evo differences of the early settlers on the various continents. Look at that Kennewick Man skull. He still had a pretty sizable brain pan and he was only like 9K years old

I had a evolution once't . . . it stained the sheets, and i got my @ss whipped.

We don't get great presidents anymore do we Rog

Dumoldme
I thought it hadn't started.

For evolution to operate in the sense of transforming a species, isn't it necessary for a given mutation to provide an advantage to those members of the species who have it so that in time they "out survive" the others?

If so there will have to be a mutation that gives those humans that have it a survival advantage over all others. What might that be? We don't need to be faster, or stronger. We don't need longer necks or more durable teeth. We don't need to be ny smarter than we are; in fact one could argue that less intelligent people are having more kids than the smart ones (but that's probably more a case of education and economic status).

What are children currently dieing from that a gene that renders them immune would provide and advantage so that they live long enough to pass on that gene?

I think of so many sci-fi dramas that suggest that with time we all become super brainiacs and I can't see why that would come to be. Being a brainiac doesn't give anyone a leg up in terms of survival now.

The population size and life span of modern humans would seem to work against evolutionary transformation of the species.

It's more likely that we, as a species, will take our evolution into our own hands through technology.

Well put Finn. In fact there might prove some advantage in devolution

https://www.google.com/?gws_rd=ssl#q=opposite+of+evolution

In other words, dumbing down

Wow, I'm actually surprised not to find a farmerman reply.

In answer to your question, no, genetic changes (mutation is not a good word, carrying as it does to the general public an aura of mutilation as much as mutation) do not necessarily confer an advantage. The mechanism of evolution is natural selection, meaning that any trait or morphological change which enhances reproductive opportunities will eventually become dominant in the genome. There can be, however, such changes which, while not conferring any advantage, will also not impose a disadvantage, and they would be retained.

I suspect you're caught up in the "survival of the fittest" meme. Any individual who survives is by definition fit--survival of the fittest refers to species, not individuals. The question is not one of survival, but rather of reproductive opportunity. And in evolution, it's not just a matter of what helps, but also of what doesn't hinder. Furthermore, there can be traits or morphological changes which arise from the combination of two recessive genes (this is basic Mendelian stuff here). Individuals can carry a recessive gene which neither provides an advantage nor imposes a disadvantage, but which, when combined with another recessive in an offspring, could be lethal. Some traits are gender linked, as well, and will only show up the offspring of a couple in which the trait is present in the female, and was also present in one (or both) of the males grandmothers.

All of this is understandable, if sometimes complicated. The mechanism of natural selection "rewards" those whose traits or morphological changes enhance breading opportunity, but doesn't necessarily "punish" those with traits or morphological changes which do not harm breeding opportunity.

To me "survival of the fittest" essential means the individual lives long enough to reproduce and spread its genes (including any mutated ones). A mutation that conferred super strength to an individual might allow it to survive long beyond any of its fellow species members, but it would be useless in terms of aiding in transforming that species unless the super strong individual mated and produced progeny with the same gene and so on and so on.

I have a difficult time understanding though how a, let's call it a "neutral" mutation gets passed on enough to become common to the species in the absence of an "advantageous" mutation.

For discussion purposes lets say that a mutation that resulted in small red dots on a human's elbows appeared. I can't imagine this creating an advantage or disadvantage in terms of the ability to reproduce. Let's also say it's a dominant gene. The human with the mutation has ten children who all carry the gene and all of their offspring carry it as well. Even if they are fantastically prodigious in terms of reproduction the "red elbow dot" gene isn't going to become common among homo sapiens, unless they also carry a gene that gives them an advantage in terms of reproduction.

With the exception of a mutation that somehow provides immunity to a given plague or radiation, I just don't see any giving the necessary advantage to individuals who will pass it on and transform the human species.

As our ability to tinker with genes grows, even "disadvantageous" genes may not create an actual disadvantage as they will be neutralized.

Humans only have to live to puberty to pass on their genes, and as we can see all around us there are individual humans who are far less than perfect specimens passing on their genes. Modern medicine keeps alive an untold number of children who would have died only a hundred years ago.

In the absence of an apocalypse that returns us to the same evolutionary playing field as all other species, I think our evolution through natural selection has come to an end.