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→History according to Creationists
==History according to Creationists==
==History according to Creationists==
"Malnutrition and longer life spans could cause features similar to those seen in Neanderthal skeletons." If malnutrition was a cause of features then the features would not be passed down to their offspring. Only genetic mutation would cause this, thus speciation. Please explain this stance for as of now it A. shows that neanderthal was speciated B. that the statement is incorrect about nutrition causing the features and that they were homo sapians if they had the same nutritional avaliblity as the rest of man kind.--[[User:Tims|TimS]] 11:46, 14 May 2007 (EDT)
"Malnutrition and longer life spans could cause features similar to those seen in Neanderthal skeletons." If malnutrition was a cause of features then the features would not be passed down to their offspring. Only genetic mutation would cause this, thus speciation. Please explain this stance for as of now it A. shows that neanderthal was speciated B. that the statement is incorrect about nutrition causing the features and that they were homo sapians if they had the same nutritional avaliblity as the rest of man kind.--[[User:Tims|TimS]] 11:46, 14 May 2007 (EDT)
===mtDNA==
In 1999, scientists successfully extracted a 345 base pair sequence of mtDNA from a second Neandertal, a 29,000 year-old fossil of a baby recently discovered in Mesmaiskaya cave in south-western Russia. (Ovchinnikov et al. 2000, Höss 2000) The results of this study were similar to the previous ones, putting the Mezmaiskaya specimen outside the range of modern human mtDNA.
In addition, the two Neandertals are fairly similar, differing from each other in 12 base pairs. The difference is greater than that usually found between pairs of modern Europeans or Asians (only 1% of whom differ in 12 or more places), but comparable to the differences between modern Africans (37% of whom differ by 12 or more).
The distance between Mezmaiskaya and a particular modern human sequence known as the reference sequence (Anderson et al. 1981) was 22, compared to 27 for the first Neandertal. (However, no figures are given for the minimum, average and maximum distances between Mezmaiskaya and modern humans; it is unclear whether Mezmaiskaya is in general closer to modern humans than Feldhofer is.)
The phylogenetic analyses of Ovchinnikov et al. show the two Neandertals grouped together, and separated from all modern humans. As with the first specimen, Mezmaiskaya also appears to be equidistant from all groups of modern humans, strengthening the conclusion that Neandertals are not closely related to modern Europeans.
Because this second individual was discovered about 2,500 km (1,500 miles) from the first, it provides very strong confirmation of the previous results.
The fact that its mtDNA was also fairly close to that of the first Neandertal makes it much less likely that Neandertals and the ancestors of modern humans were both part of an interbreeding population with a large amount of mtDNA genetic variation that has been mostly lost:
"In particular, these data reduce the likelihood that Neanderthals contained enough mtDNA sequence diversity to encompass modern human diversity" (Ovchinnikov et al. 2000)
Interestingly, the preservation of the Mezmaiskaya specimen appears to be much better than that of the Feldhofer specimen. It is so good, in fact, that there is a possibility that its entire mtDNA genome may be able to be sequenced, and there is even a possibility that some of its nuclear DNA may be retrievable.
mtDNA from a third Neandertal
In 2000, scientists announced the sequencing of a third Neandertal mtDNA specimen from a cave at Vindija, Croatia (Krings et al. 2000). When the three Neandertals are compared with modern humans, all three of them cluster together, and apart from all modern humans. This conclusion is reinforced by a study by Knight (2003). Knight excluded from the comparison sites in the mtDNA genome which are known to have mutated more than once, and which are therefore poor indicators of phylogenetic relationships. His study strongly confirmed earlier ones showing deeply divergent histories for modern human mtDNA lineages and the known Neandertal ones.
Like modern humans, Neandertals had low genetic diversity compared to apes. The diversity of the three Neandertal mtDNA sequences (3.73%) is lower than that of chimpanzees (14.82+/-5.7%) and gorillas (18.57+/-5.26%), and similar to that of modern humans worldwide (3.43+/-1.22%). If modern humans are sorted into continental groups, the diversity of the three Neandertals is similar to (within one standard deviation of) that for Africans, Asians, native Americans and Australian aboriginals, and Oceanians. Modern Europeans, who live in approximately the same region as the Neandertals, have less diversity than the Neandertals.
Still more Neandertal mtDNA
Schmitz et al. (2002) reported on a fourth Neandertal mtDNA sequence from the second Neandertal fossil found at Feldhofer, the site in Germany at which the first Neandertal fossil was found. It was closely related to the previous Neandertal mtDNA sequences.
Serre et al. (2004) were able to sequence mtDNA from four other Neandertal fossils, along with mtDNA from five early modern humans. The four Neandertals all had mtDNA similar to those found in the previous Neandertals. Serre and his colleagues found no evidence of mtDNA gene flow between modern humans and Neandertals in either direction, but could not rule out the possibility of limited gene flow. Interestingly, the mtDNA sequences from the Vindija Neandertals, which have a less extreme Neandertal anatomy than the classic Neandertals, and are considered transitional between modern humans and classic Neandertals by some scientists, were no closer to modern humans than the rest of the Neandertal fossils.
Is the Neandertal outside the human range?
Yes.
Note that because two modern human sequences are 24 bases apart, while the smallest Neandertal/human difference is only 22, does not mean the Neandertal sequence is within the range of modern humans. To use an analogy, suppose we measured the height of 994 adult humans, and they varied from 4'8" to 6'8" (a difference of 24 inches). Suppose we then found a skeleton which was 8'6" in height. No one would claim that it fell within the modern human range because it was closer to the nearest human (22 inches) than the tallest human was from the shortest human (24 inches).
Note also that the two figures (22 and 24) are measuring very different things, making it invalid to compare the two figures. Just as the Neandertal was compared against 994 modern humans, any of those humans could be similarly compared against the other 993 humans. We could compute the minimum, average, and maximum distance from that human to the other humans, just as was done for the Neandertal. If we calculated those values for all the humans, we could then calculate minimum, average and maximum values of all the individual minima, averages and maxima, and compare those values against the equivalent values for the Neandertal.
We do not know from the Krings et al. 1997 paper the distribution of minimum distances of humans from other humans. The smallest such value is 1. The largest such value might, I suspect, be as much as 5. The same value for the Neandertal is 22, well outside the human range.
For average distances of humans to other humans, we know the average value is 8.0. The minimum average distance will be a little less; the maximum average value must be at least 12 (this can be deduced from the fact that there are two humans 24 apart) and less than 24; I would guess it might be about 16 for a highly atypical human. For the Neandertal, the value is 27, again well outside the human range.
For maximum distances, the maximum such value is 24, but for most humans, the maximum distance to any other human will be less than that. The value of 24 is highly atypical, because it is taken between the two individuals who have indepently diverged farthest from mitochondrial Eve, and is the maximum of nearly half a million (994 * 993 / 2) comparisons among modern humans. For the Neandertal, the value is 36, again well outside the human range.
In other words, for all three measurements (minimum, average and maximum distances to other humans), the Neandertal measurement is much larger than the maximum value of the same measurement from a sample of 994 modern humans, and even further from the average value. The Neandertal is not merely outside the human range, but well outside it.
:--[[User:Tims|TimS]] 11:53, 14 May 2007 (EDT)