THE END OF EVOLUTION?

The original question in this thread was about the end to evolution. I've been wondering whether evolution has reached a dead end in homo sapiens. It seems to me that we should be seeing more homo species. Homo sapiens have only been around about 130 000 years but there have been more of us on the planet than other homo species. Homo habilis, homo ergaster, and homo heidelbergenisis were around for longer but were relatively few in number. At 10000 BC we were 5 million and that was only due to agricultural techniques. Now we are close to 7 billion. With the depletion of the ozone, toxic chemicals, pollutants, and radioactive waste there should be a higher degree of mutation but we have seen no new homo species. Are we the end of the line?

We have changed our environment drastically in the last thousand years. You mentioned pesticides and aids. Think of the changes in the makeup of the atmosphere, radiation, crowded conditions with increased competition, and the differences in our diet due to large scale farming, chemicals, ingested pills of all sorts, immunizations, etc. There have also been many changes in the water we drink. If it hasn't happened by now, I don't think it's going to. Why is that? What actually qualifies as "separated?" We have had the separation of aboriginal peoples in the Americas. There have been other group separations for long periods. How large a population does it need to be?

So it seems like we're talking hundreds of thousands of years. I'm still having trouble wrapping my head around why you need separation. Are you saying all species that evolved were separated from a main group with which they could mate (same species)? How many would have to be separated? What do you mean by genetic intermingling? Every new human is the result of genetic intermingling.While trying to find an estimate on the population of homo habilis I came across an article (Nature 448, 668 - 691) that indicated that homo habilis and homo erectus coexisted. I know that habilis has been under some debate, at least some specimens were being argued over. Am I out of date? Is my order in post 339 still more or less accepted? Has habilis been kicked out of the line up?

Percy said in post 143 that it is required that genes not intermingle. The salamanders at either end are interbreeding with other groups.You said that the two adjacent groups do not interbreed. Does that mean that they cannot interbreed?

Clearer. Thanks. Is there a situation where A to I are alive today or is this just speculation?I'm a little confused by "they are not exactly the same species, nor are the they different species." How do you define a species? Wouldn't that have to be unable to interbreed to make them different species?Getting back to my original point, I think homo sapiens are the end. We have had incredible opportunities to become a new species with the exponential population growth, competative pressure beyond any homo, environmental stresses that no other homo has been exposed to, mutanogenic substances galore, and still no new species. If it was going to happen, it should have by now.

I check taxonomy and the greenish warblers are all the same species. Are there any examples where ring species have created different species?

I googled and looked under a number of sites and they put greenish warbler in Phylloscopus trochiloides. Is there new information that is not yet posted? What other species are there in this ring series that greenish warblers have become?Trying to get back to the original thread and my previous submission it still seems to me that because
a) the number of homo sapiens that have existed I believe is larger than the number of homo habilis or homo ergaster or homo heidelbergenisis that have existed (I tried to find numbers for these but couldn't. I'm infering that since they were limited geographically and had no agricultural techniques their numbers were small. Anyone know?)
b) there are far more mutanogens today
c) the competative stresses are stronger on sapiens than any other homo group
d) the environmental stresses are stronger
e) there have been no new homo species in the last 100 000 yearsthat we are the end of evolution. If it was going to happen, it should have happened by now.

I believe that was infered in the question "End of evolution." We have been talking about whether new homo species will emerge. Do you think they will? If so, why? Here is the base for my assumption:
"a) the number of homo sapiens that have existed I believe is larger than the number of homo habilis or homo ergaster or homo heidelbergenisis that have existed (I tried to find numbers for these but couldn't. I'm infering that since they were limited geographically and had no agricultural techniques their numbers were small. Anyone know?)
b) there are far more mutanogens today
c) the competative stresses are stronger on sapiens than any other homo group
d) the environmental stresses are stronger
e) there have been no new homo species in the last 100 000 years"With a smaller evolutionary potential the homo genus created three new species if you accept the habilis to ergaster to heidelgenisis to sapiens model. Why haven't new homo species appeared? I think that we are a dead end. (present company excluded)

Yes, I saw the subspecies but again, no new species. Science basically asked two questions: What is it called and how does it work? Those scientists making a career in taxonomy have established a maze of rules for KPCOFGS. I'm not an expert in taxonomy but I think their setup is reasonably sound. I know that there is still argument but there always will be when you put scientists in a room. I am just talking about humans. I don't think humans are the be all and end all. Sometimes, looking at our current crop of sapiens, I feel like we devolved from Pan. (tic) I don't see any evidence of further speciation in homo sapiens. Change - yes. Speciation - no.

Almost seven billion people currently on the planet. 1.4 billion in China and 1.1 billion in India. Around 70 % of the world's population don't have enough to eat. Just because we can enjoy the marvels of the West Edmonton Mall, doesn't mean it's available to the rest of the world. By environmental pressures I meant changes in diet, immunizations, changes in weather, changes from nomadic to settlements, changes in the water we drink, changes in the composition of the atmosphere. No, it can't be 100 % ruled out but it seems unlikely since nobody has found a fossil record and it should be easier to find than habilis, ergaster, and heidelbergenisis.How's the weather out there? We still have snow in our backyard!!!

Rainy weather out there making you a little grumpy?Let me attempt to annoy you further with more inane repetition.
I posit that no new species will come from homo sapiens. Hit me with the actual research that I've been ignoring and convince me otherwise.

I am not talking about micro or macro in general. I'm talking about a new species coming out of homo sapiens. Percy said in post 143 that for speciation to occur it is required that genes don't intermingle. How can that happen with homo sapiens in todays global village?

There are approximately seven billion homo sapiens living on the planet today, 70 % of that is almost five billion. How many ergaster lived during the entire era of their existance on earth? Are you saying that you have discovered other species that have come out of homo sapiens? Prepare you Nobel speech. I'm submitting your name.

Who is arguing against evolution? Perhaps you have not been following the thread but the discussion is about whether homo sapiens are an evolutionary dead end or whether another species will come from the homo sapien line. I don't think you could. There is some work being done on replicating DNA from an extinct species using Polymerase Chain Reaction or splicing genes into the genome of another animal. This process is far from creating a replica of the extinct living thing.I maintain that it is highly unlikely that any species split from homo sapiens during the last 100 000 years and has not been discovered.