|
Author
|
Topic: "Homo troglodytes" Genome Project, DNA 96% {us}
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
|
Message 1 of 28 (239468)
09-01-2005 10:00 AM
|
|
|
We are related. From Man, chimps share genes - Comparison of genomes shows thousands are virtually identical (click):
The 67 scientists from five nations leading the chimp genome project are reporting their results today in a series of eight papers published in the journal Nature. Researchers leading the project described their work Wednesday at a Washington press conference. Lining up 3 billion bits of genetic code, the chimp genome team determined that 96 percent of the protein-coding genes in both chimps and humans were identical, while in some stretches of DNA where genes either regulate other genes or whose function is unknown, as much as 99 percent of the genetic material in both is identical, the scientists concluded. So we now have complete genome comparisons instead of estimates, and the final count is 96% identical. This makes us more closely related than many species that are lumped into the same {Genus}, and is more evidence that Chimps should be considered Homo troglodytes as some have suggested.
Among the 35 million tiny bits of DNA in the human genome that differ from chimps, for example, lie clues to the manner in which natural selection -- the basic machinery of evolution -- has given humans the unique ability to walk upright, to use language and to think, reason and develop complex tools, said Dr. Robert Waterston of the University of Washington, the senior author of the principal comparative study. Mutations in the DNA of many of those genes may well have occurred within the past 250,000 years, and because they proved so beneficial, they spread rapidly throughout the human population, he said. Some classes of genes, however, appear to have changed relatively rapidly in both chimps and humans, the scientists say. They include genes involved in hearing, transmission of nerve signals and production of sperm. If this can be confirmed, these would be the genetic changes that separated Homo sapiens from Homo heidelbergensis and push back other evidence of the first Homo sapiens occurring a little over 160,000 years ago, from "mitochondrial eve\adam" to the oldest known anatomically modern fossils. This should not be a surprise. And this would touch on some previous claims of faster genetic change in humans than other apes, while changes in sperm genes would also be evidence of sexual selection. From Humans March to a Faster Genetic "Drummer" Than Other Primates, UC Riverside Research Says (click):
During the same amount of time, humans accumulated more genetic novelties than chimpanzees, making the human/chimpanzee genetic distance larger than that between the chimpanzee and gorilla. Metaphorically speaking, Dugaiczyk said, Humans and other primates march to the rhythm of a drum that looks identical; the same size, shape and sound. But, the human drum beats faster. This last study was touted as "Research Runs Counter to Darwins Theory of Natural Selection"
The process was not random, Dugaiczyk said, and it was not subject to an environmental "natural selection," separating winners and losers as theorized by Darwin. "We are not contending that natural selection does not exist, but that in this instance it is a chemical process within human chromosomes that explains why humans have an explosive expansion of DNA repeats, and other primates do not," Dugaiczyk said. However this view ignores the contribution of sexual selection in the development of the human mind and other characteristics. Run-away sexual selection can easily push the envelope of development faster and further than survival selection, which must wait for opportunistic events to be applied. Back to the new results on the Chimp Genome: Again from Man, chimps share genes - Comparison of genomes shows thousands are virtually identical (click):
Scientists have estimated from the fossil record that the evolutionary lineages of humans and the great apes like chimpanzees diverged from a common ancestor between 5 and 8 million years ago, and the chimp genome team believes the split must have occurred roughly 6 million years ago. Someone here said 4 million and I said I thought it was closer to 7 million; I'll take 6 as a good compromise  .
Over all the millennia since that time, relatively few changes have occurred in the chimp genome, Waterston and his colleagues said. That has placed humans at a disadvantage in some areas. Chimps, for example, have been able to resist many infections like HIV and AIDS, and they don't get malaria, diabetes, cancer or Alzheimer's -- while humans can succumb to all these maladies. Yet, as Collins noted, "we have peeked into evolution's lab," and it's just these differences that could provide a new understanding of those diseases as researchers pursue their quest for prevention and treatment in new directions. What will creationists (and others who feel the need to regard humans as "special") do when major medical breakthroughs in human health come to us from our cousins? Enjoy. ps -- I'm thinking {Human Origins} ... This message has been edited by RAZD, 09*01*2005 10:01 AM Edited by RAZD, : replace italic code in title with " seeing as italics don't work in titles anymore?
Join the effort to unravel {AIDS/HIV} {Protenes} and {Cancer} with Team EvC! (click)
we are limited in our ability to understand
by our ability to understand
RebelAAmericanOZen[Deist
... to learn ... to think ... to live ... to laugh ...
to share.
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
|
|
Message 4 of 28 (239521)
09-01-2005 11:55 AM
|
Reply to: Message 3 by Dr Jack
09-01-2005 11:10 AM
|
|
and yet, in one species:
There is more morphological (surface differences) than between human and chimp.
morphology n. pl. morphologies
1. The branch of biology that deals with the form and structure of organisms without consideration of function.
2. The form and structure of an organism or one of its parts: the morphology of a cell; the morphology of vertebrates. Thus by your argument we should consider chimps to be Homo sapiens. Enjoy. This message has been edited by RAZD, 09*01*2005 11:57 AM
we are limited in our ability to understand by our ability to understand
Rebel AAmerican .Zen [Deist
{{{Buddha walks off laughing with joy}}}
| This message is a reply to: | | | Message 3 by Dr Jack, posted 09-01-2005 11:10 AM | | Dr Jack has replied |
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
|
|
Message 7 of 28 (239798)
09-01-2005 8:58 PM
|
Reply to: Message 6 by MangyTiger
09-01-2005 8:42 PM
|
|
Yes it was done on troglodytes. I think if you look at the (well done) thread Sylas had on {neander\chimp\human} DNA that this is addressed http:// EvC Forum: Comparisons of Neandertal mtDNA with modern humans and modern chimpanzees It appears that human\bonobos are more different than human\chimp Note that {redwolf} is Ted Holden. Yes, I would like to see the full Bonobos genome, particularly as they appear to be headed for extinction in the wild. see http:// EvC Forum: What is the evolutionary advantage to religion? This message has been edited by RAZD, 09*01*2005 08:58 PM
we are limited in our ability to understand by our ability to understand
Rebel AAmerican .Zen [Deist
{{{Buddha walks off laughing with joy}}}
| This message is a reply to: | | | Message 6 by MangyTiger, posted 09-01-2005 8:42 PM | | MangyTiger has not replied |
| Replies to this message: | | | Message 11 by sfs, posted 09-02-2005 1:14 PM | | RAZD has replied |
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
|
|
Message 9 of 28 (239810)
09-01-2005 9:48 PM
|
Reply to: Message 8 by MangyTiger
09-01-2005 9:05 PM
|
|
Re: Human/chimp vs. dog/dog
Can the same be said about the differences in the two dogs in your picture? I'm not expert enough to say for sure, but my money is on "no". Of all of those differences the only one that I would agree doesn't fit the different dogs is
The position of the foramen magnum (the hole through which the spinal cord passes) places the skull in front of the spine rather than balanced on top of the spinal column as seen in humans. The others are much smaller at younger ages due to the extensive neoteny in humans: from http://dsc.discovery.com/news/afp/20031006/laughter.html hmmmm, same reaction to tickling? Great Dane Skull (note size of snout and teeth):
From http://www.evolutionnyc.com/..../product-id/29151.html I can't find just skull of a small dog (to show the teeth), but this might give something of the idea:
From http://www.gobaeng.de/product_info-products_id/3729 (pugs may have been selected for neoteny characteristics too) Is one difference enough to justify a different Genus? Thanks.
| This message is a reply to: | | | Message 8 by MangyTiger, posted 09-01-2005 9:05 PM | | MangyTiger has not replied |
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
|
|
Message 15 of 28 (240223)
09-03-2005 8:45 AM
|
Reply to: Message 12 by randman
09-03-2005 1:28 AM
|
|
Re: may be of interest here
randman writes: Personally, this is interesting because it confirms a hunch, that all those scenarios declaring man began to walk upright when the land dried up to grassy Savannahs was essentially a myth based on very little actual evidence. To add to what PaulK has already said, this particular hypothesis has been invalidated by the fossils of upright walking hominids that pre-date the arrival of the savannah environment. It would also appear that we had already evolved our penchant for {less hairy appearance} by then, but that is a separate issue (see the sexual selection thread where these points are discussed). You seem to have some problems with the concept of falsifyable theories, as this is not the first time you have refered to such as myths. All theories, even the best possible derived scientific theories based on multiple divergent piles of evidence that have passed many falsification tests, can always be invalidated by the nest piece of information found. This does not make them "myths" it makes them mistakes based on insufficient information. Certainly when the "Savannah Theory" of pedestrian development was proposed it was based on the evidence available at the time. The active falsification of theories is how science moves forward, because the next theory takes into account the new information and then makes predictions for what we should find. Enjoy.
we are limited in our ability to understand by our ability to understand
Rebel AAmerican .Zen [Deist
{{{Buddha walks off laughing with joy}}}
| This message is a reply to: | | | Message 12 by randman, posted 09-03-2005 1:28 AM | | randman has not replied |
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
|
|
Message 16 of 28 (240224)
09-03-2005 8:47 AM
|
Reply to: Message 11 by sfs
09-02-2005 1:14 PM
|
|
It's in the graphs that Sylas made. The actual discussion\conclusion that you refer to was on another thread, this one has the evidence for it. I thought the bonobos were closer to us than troglodytes too.
| This message is a reply to: | | | Message 11 by sfs, posted 09-02-2005 1:14 PM | | sfs has not replied |
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
|
|
Message 17 of 28 (240225)
09-03-2005 9:01 AM
|
Reply to: Message 10 by Dr Jack
09-02-2005 4:31 AM
|
|
Your argument fails to show that the morphological differences betweeen humans and chimps exceeds those of every other {species vs Genus} divisions.
Scientists were perfectly able to distinguish superficially very similar animals (such as Echinacea and Hedgehogs) using morphology long before genetic analysis became available, indeed before evolution was even identified. And they also made some mistakes based on just morphology that have been corrected now that we have the genetic information. This is just another such case, but complicated (as noted by Lithodid-Man) by our species-biased outlook. Heck some of us have trouble accepting other races ...
Dogs are considered the same species ... And are also an example of artificial selection which, frankly, bends things somewhat. But that makes them a perfect example of the failure of just morphology as a basis for differentiating species. This is not a refutation of the genetic similarity of chimps and humans. I don't mean to belittle morphology, or relegate it to the scientific dust-bin, but it is one part of the picture of species and higher (artificially constructed human concept) divisions. {abe}: and I have already 'recanted' the "more" in response to MangyTiger
RAZD, msg 3 writes: There is more morphological (surface differences) than between human and chimp.
msg 9 writes: Of all of those differences the only one that I would agree doesn't fit the different dogs is ... Is one difference enough to justify a different Genus? So if one were serious they would catalog the morpological difference between all closely related species and see if there were some common level of {noticeable diffences} that marked such divisions into species, do the same for varieties (like dogs) and see if there is some kind of correlation curve that would take us to genus and above ... and then see where the differences between human and chimp fall on that curve. Sorry to take so long getting back to you, but I am really disturbed by the events in nola, the abject failure to take care of the people just stuns me. This message has been edited by RAZD, 09*03*2005 09:11 AM
we are limited in our ability to understand by our ability to understand
Rebel AAmerican .Zen [Deist
{{{Buddha walks off laughing with joy}}}
| This message is a reply to: | | | Message 10 by Dr Jack, posted 09-02-2005 4:31 AM | | Dr Jack has replied |
| Replies to this message: | | | Message 20 by Dr Jack, posted 09-05-2005 7:41 AM | | RAZD has replied |
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
|
|
Message 21 of 28 (240530)
09-05-2005 9:21 AM
|
Reply to: Message 20 by Dr Jack
09-05-2005 7:41 AM
|
|
middle.
Ah, middle ground.
But I do think it has a role to play if our categories are to be useful. Lithodid's point about recognising differences more readily in similar species is a good one though Let us say that we share enough characteristics that we could be considered in the same genus in comparison to other species\genus classifications, but that the evidence is not conclusive enough (and the point is still being debated) to make the change at this time. I had some information ona recent proposed reclassification of Pan into the hominidae family, but I've lost the link. Perhaps this is just another reason to change to the phylo-code approach | American Scientist
The core proposition of the PhyloCode is to abandon Linnean hierarchical ranks and recognize only species and clades. (A clade is a group of all the organisms that share a particular common ancestor.) The scheme does not dispense with hierarchical organization, as clades will be nested within one another according to phylogeny. The key advantage is that changes made in one part of a classification do not require altering other group names. There is some interesting information here about hominid classifications and that argues for Homo troglodytes ... or to exclude a lot of other hominids from the family? http://www.rfthomas.clara.net/papers/porshnev.html
The main criterion for placing fossil forms in the family Hominidae is in practice the presence of accompanying stone implements. Such practice contradicts the purely morphological principle of classification. Before it opens a can of worms, creating more divisions and sub-divisions. There is this MRI study of brain similarities:
MRI reveals similarities between the human and chimpanzee brain
Studies such as this confirm that human and chimp brains are not only asymmetrical, but asymmetrical in the same way. The findings echo previous looks at the non-limbic parts of chimpanzee brains, which also appear human-like in their patterns of asymmetry. This fact, especially if studied in the context of functional behaviors that reflect asymmetries, may help scientists get a better fix on the evolution of the limbic system in all primates, including humans. But this may also be of interest: http://www.mnh.si.edu/...norigins/whatshot/2002/wh2002-2.htm
Humans and chimpanzees share 98.7% of their DNA sequences yet are very different in morphology, behavior and cognitive abilities. According to this paper, these distinctions result not from differences in the protein products produced by the DNA, but in the ways in which the genes are expressed. Gene expression changes can occur when genes are deleted or duplicated, or when levels of transcription factors change. The study found high levels of intraspecific variation in gene expression. They showed that the amount of variation between individuals of the same species was high compared with the amount of variation between chimpanzees and humans. However, a different pattern was discovered in the expression patterns of the brain, with chimpanzees showing greater similarity to macaques than to humans. The human brain had a rate of change of gene expression levels that was 5.5 times faster compared to the other lineages. Could we be looking at "macroevolution" and not recognizing it because we are the ones? Enjoy.
we are limited in our ability to understand by our ability to understand
Rebel AAmerican .Zen [Deist
... to learn ... to think ... to live ... to laugh ...
to share.
| This message is a reply to: | | | Message 20 by Dr Jack, posted 09-05-2005 7:41 AM | | Dr Jack has not replied |
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
|
|
Message 25 of 28 (240713)
09-05-2005 9:11 PM
|
Reply to: Message 23 by JustinC
09-05-2005 6:18 PM
|
|
Perhaps, but we can use the phylo code, and we could talk about "degrees of separation" rather than {genus\family\etc} divisions which are arbitrary and a left-over from the time before genetics (BG) This would answer problems of ring-species to phylum differentiation while still being able to track interrelations between close relatives. I'll admit to being "old-school" here and have trouble leaving linnaen taxonomy behind. from | American Scientist
The core proposition of the PhyloCode is to abandon Linnean hierarchical ranks and recognize only species and clades. (A clade is a group of all the organisms that share a particular common ancestor.) The scheme does not dispense with hierarchical organization, as clades will be nested within one another according to phylogeny. Now that's all well and good, but how do we convert linnaean to phylo nomenclature?
at least a dozen proposed methods are on the table. Several involve retaining the binomial name (genus, species: Homo sapiens) but formatting it differently to distinguish from clade names, so that human beings might become homosapiens in the Hominid clade. and then we would ask if that puts pantroglodytes also in the Hominid clade, and what is the degree of separation there? one could then look at the number of other branches off either and from that judge the degree of relatedness, and in this regard all the ancestral species of hominid back through australopiticusafarensis would be intermediate species. But it still leaves pantroglodytes as the closest living relative, so that would fomr one clade, whether you considered that {genus} or a {family} differentiation would not be that important. I can't say I know how phylocode deals with {archaic\extinct} species designations. (still learning after all these years)
we are limited in our ability to understand by our ability to understand
Rebel AAmerican .Zen [Deist
... to learn ... to think ... to live ... to laugh ...
to share.
| This message is a reply to: | | | Message 23 by JustinC, posted 09-05-2005 6:18 PM | | JustinC has not replied |
|
RAZD
Member (Idle past 1435 days) Posts: 20714 From: the other end of the sidewalk Joined: 03-14-2004
|
The biggest problem I see for the phylo code is how to deal with the nodes of the branches. Some proposals have been put forward but none I have seen seem too compelling as a system, and when the name used depends on the (arbitrary) order of the branches then we can end up with disagreement on which is "more" correct. Until then we will stagger along with the Linaean system, possibly converting only species to phylo?
we are limited in our ability to understand by our ability to understand
Rebel AAmerican .Zen [Deist
... to learn ... to think ... to live ... to laugh ...
to share.
| This message is a reply to: | | | Message 27 by Chiroptera, posted 09-06-2005 1:31 PM | | Chiroptera has not replied |
|
™ Version 4.2
