Genes unite us with H. erectus

mortongr@flash.net
Sat, 20 Nov 1999 21:44:49 +0000

New genetic data is clearly showing that we are decended from more than one
group of Homo erectus and show a population expansion which occurred
sometime between 400 thousand and 1.3 million years ago.

There are three views of human evolution--the extreme out of Africa view.
The extreme of this view would claim that there was no interbreeding
between anatomically modern man and his archaic forebearers. Ian Tattersall
is one of the few who hold to the extreme view. Then there is the much
denigrated multiregional view. This view in its extreme view (which was
advocated by Carlton Coon and not by Wolpoff). This view holds that each
individual population became sapiens at different times with no
intermixture of genetics between the populations. And finally there is a
view which is somewhat intermediate between the two and it is the
assimilation view. Strictly speaking Wolpoff is an assimilationist not a
multiregionalist ala Coon. This view believes that modern mankind did arise
in Africa but as he spread out over the earth, there was some level of
interbreeding which assimilated the archaic populations into modern
humanity. The extremes are held by very few. Even Stringer, who is
considered an out of Africa advocate believes in interbreeding between
Neandertals and modern men and thus in some fashion is also an
assimilationist. The discussion between Wolpoff and Stringer appears
largely to be over how much interbreeding. Stringer says little(Stringer
and Gamble, 1993, p. 193) Wolpoff says much and thus the name for his idea
is Regional Continuity ( Wolpoff and Caspari, 1997, p. 208)

A recent article by Alan R. Templeton (1999) takes on directly the extreme
out of Africa view. This is the view that modern humans arose in Africa
around 100-120,000 years ago and then replaced all previous peoples on
earth at that time.Thus the expectation of this view is that there is
little genetic connection between us and Homo erectus or Neanderthal.

As noted before, some apologists have taken this view that there is a gap
between us and the fossil men. Hugh Ross beleives that all hominids prior
to 60,000 years ago are merely bipedal mammals with no genetic links to
us--a view that is so ridiculous as to really not require rebuttal ( Ross,
1991, p. 159-160; Ross, 1995, p. 3; Ross, 1995, p. 22). Wiester beleives
that H. erectus is not related to us. (Wiester 1983, p. 173, 188). Davis
and Kenyon also believe that H. erectus is not related to us (Davis and
Kenyon, 1993, p. 110). The data in Templeton's article clearly refutes
categorically the concept of a gaps in the human genome.

The extreme out of Africa view postulates several genetic gaps should
exist. First there should be a gap between modern humans and all previous
archaic species. Secondly, there should be a gap between Africans and
non-Africans. Then a gap between Europeans and Australasians, and finally a
gap between Australians and Asians. The gaps should be progressively
smaller as one reads the list above.

The data of genetics is often presented as a series of
dendrograms--phylogentic trees. And it is these dendrograms which are then
used to support the gaps and thus the extreme form of the out of Africa
view. The dendrograms are interpreted as showing separate evolutionary
lineages. Templeton disagrees strongly with this. He proceeds to knock it
out along several fronts. First he notes that when genetic differences are
plotted against population geographical separation, that a smooth curve is
produced. If the population genetics actually fit a phylogenetic tree there
should be less correlation between genetic distance and geographic
distance. Templeton says:

"For example, under the candelabra model, all non-African human populations
'split' from the Africans at the same time, and therefore all genetic
distances between African and non-African populations have the same
expected value. When genetic distances instead reflect the amount of gene
flow, 'treeness' constraints are no longer applicable. Because gene flow
is commonly restricted by geographical distance, gene flow models are
expected to yield a strong positive relationshiip between geographical
distance and genetic distance. Figure 4B places the populations on a
two-dimensional plot in a manner that attempts to reflect their genetic
distances from one another, particularly nearest-neighbor distances, while
otherwise attempting to minimize the total sum of brach lengths (formally,
a neighbor-hoining dendrogram). Figure 4B uses the same genetic distance
data used to generate the tree in Figure 4A, but without imposing all the
constraints of treeness. Note that Europeans fall between Africans and
Asians as predicted by their geographical location-in contrast to the
candelabra model prediction of equal genetic distances of Europeans and
Asians to Africans. The computer programs used to generate 'trees' from
genetic distance data will do so regardless of what evolutionary factors
generated the distances. It is therefore the obligation of the users of
such programs to ensure that the genetic distance data have the properties
of treeness before representing their data as a tree. To present trees that
do not have the properties of treeness is analytically indefensible, and
worse, it is biologically misleading." (Templeton, 1999, p. 638-639)

and

"The failure of human genetic distances to fit treeness is ubiquitous
whenever tested (Bowcock et al. 1991; Cavalli-Sforza et al. 1996; Nei and
Roychoudhury 1974, 1982). Nevertheless, these same authors persist in
presenting the relationships of the major human 'races' as an evolutionary
tree." (ibid).

New techniques have been developed which show that population movements as
small as 135 people every 2000 years would maintain the genetic continuity
of the human race over a long time. As Relethford (1995,p. 54) states,

"However, if we consider the likelihood of migrants traveling in groups,
the numbers become probable. For example, a group of 20 migrants every 50
generations would produce the same average rate of migration and would
require movement over 200 km per generation, or 8 km per year. If we
imagine a group of 40 migrants, the corresponding values are 100 km per
generation and 4 km per year. THese estimates, although crude, fall
comfortably within the range of migration of contemporary foragers."

This would be similar to the gene flow that maintained lions, wolves brown
bears without significant speciation as they too conquored the continents
of Africa, Europe and Asia. (Tudge, 1995, p. 263).

Now what evidence is there of this gene flow? It lies in the coalescence
time of the nuclear genome. If there were a total replacement of ancient
hominids by anatomically modern men 100-200 thousand years ago, then all
genetic events which took place earlier than that should not be found in
the data of the genome. Yet, the coalescence time of the nuclear genes is
of the order of 1 million years. Templeton writes (1999, p. 644):

"Genetic interchange between Africans and Eurasians over long periods of
human evolutionary history is also strongly suggested by a hemoglobin beta
locus tree. The coalescence of an autosomal gene is expected to be about
four times as old as that of mtDNA or Y-DNA, and this seems to be the case
for the beta locus. Consequently, the patterns of widespread gene flow
across Afrrican and Asia observed with the hemoglobin locus predate the
hypothesized 'replacemnt' event of the recent candelabra model. Obviously,
if such a replacemnt had occurred, these earlier genetic signatures of gene
flow should have been obliterated."

The hemoglobin differentiation in human populations took place between 400
thousand and 1.3 million years ago. As Templeton notices if a small group
of founders replaced everyone on earth 200 thousand years ago, there should
be a lot less diversity at this location. The same thing has been found in
other nuclear genes. As Templeton concludes, "There is no obvious way to
reconcile the hemoglobin data with a recent out-of-Africa replacement
event." (1999, p. 646). Given the evidence of ancient genetic events in the
human species, the only way to reconcile the data with our theological
views is to reject categorically the concept that we are unrelated to the
ancient hominids.

So why does the mtDNA appear to say that mankind is only 100-200 thousand
years old and the hemoglobin work say we are older? Like a telescope that
can only see out so far, mtDNA is a genetic telescope that can only tell us
about events in the past 200,000 years. The Hemoglobin data can see much
further back in time--it is a better telescope. And it sees an earlier
population expansion--maybe another out of Africa migration. Templeton
(1999, p. 645-646) relates:

"In comparing the mtDNA (Figure 6) and hemoglobin (Figure 8) inferences, it
is important to keep two factors in mind. First, these two haplotype trees
are detecting events on different time scales. In particular, the time
depth of the hemoglobin network has a 95% confidence interval of 400,000 to
1,300,000 years ago (Harding et al. 1997). Once ultimate coalescence has
occurred in a haplotype tree, there is no information about previous events
or evolutionary forces. Therefore, the older events and forces detected in
the hemoglobin analysis would be completely invisible to the mtDNA
analysis. The oldest event detected in the hemoglobin analysis is an
out-of-Africa range expansion found among 2-step clades as nested within
the entire haplotype tree, and which therefore must have occurred close to
the time depth of the entire tree.
This out-of-Africa expansion event is obviously too old to be the one
postulated by the recent candelabra model. Because it spans the entire time
depth of the hemoglobin haplotype tree, there is no information at all
about the pre-expansion population. Hence, this old out-of-Africa expansion
could have been a colonization event of empty areas, a replacement event,
or a hybridization event in which new migrants interbred with previous
Eurasian inhabitants."

These data mean that mutations occurred in Homo-erectus/H. heidelbergensis
which we carry in our veins. It also means that the assimilation model MUST
be correct. This then allows us to accept Neanderthal human hybrids as my
previous note mentioned. For christians to claim that we are unrelated to
the erecti, merely means that they haven't studied the issues carefully.

Four hundred thousand years ago, there were no anatomically modern men on
earth, there were not even any Neanderthals. All there were was Homo
heidelbergensis and Homo erectus. The genetic data clearly shows that our
modern population has descended from different groups of them. This is
because if we were descended from only one group, we should have much less
variability in the hemoglobin data. If this is the case, then we must
include them as God-gifted humans or conclude that some people alive today
aren't human--a very bad option. Ross, Wiester, Wilcox, Davis and Kenyon
can protest all they want but the data are very clear--we descend from
different groups of H. erectus!


References

Percival Davis and Dean H. Kenyon, Of Pandas and People, 2nd edition
(Dallas: Haughton Publishing Co., 1993).

John Relethford, "Genetics and Modern Human Origins," Evolutionary
Anthropology, 4(1995): 53-63

Hugh Ross, The Fingerprint of God, (Orange: Promise Publishing, 1991).

Hugh Ross, "Chromosome Study Stuns Evolutionists," Facts & Faith, 9:3,(1995).

Hugh Ross, "Link with Neanderthals Cut by Computer," Facts & Faith, 9:3,
3rd Qtr. 1995, p. 22

Christopher Stringer and Clive Gamble, In Search of the Neanderthals, (New
York: Thames and Hudson, 1993).

Alan R. Templeton, "Human Races: A Genetic and Evolutionary Perspective,"
American Anthropologiist, 100(1999):3:632-650

Colin Tudge, The Day Before YEsterday, (London: Pimlico, 1995).

Milford Wolpoff and Rachael Caspari, Race and Human Evolution, (New York:
Simon and Schuster, 1997), p. 208).

John Wiester, The Genesis Connection, (Nashville: Thomas Nelson Publishers,
1983)
glenn

Foundation, Fall and Flood
Adam, Apes and Anthropology
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