Where did the Egyptians come from ?

Hey blitz!Although this is slightly off-topic, I'm hoping you can answer a question for me. I've asked it a number of times in various places, but no one seems to be able to help me out. To wit: if the current world population is derived from four breeding pairs - which apparently didn't interbreed - where can I read about the evidence for the incredible genetic bottleneck that took place in the population? Moreover, where is the evidence of a genetic bottleneck of staggering proportions in even one non-human species alive today? I mean, given the relatively short time span (4000 years or so), there should be evidence of a gigantic bottleneck in at least those species represented as "kinds" on the ark, no?Thanks for your help.

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Originally posted by blitz77:
Would you be talking about genetic diversity bottleneck or geological evidence for the bottleneck? Changes by microevolution occur rapidly in small populations, as you yourself should know. In large populations, diversification is a lot slower.

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Actually, I'm talking about the evidence that would be obvious in the genomes of every species alive today of either extreme polymorphism or extreme reduced polymorphism that occur in founder populations along the lines of what we observe in elephant seals and cheetahs (for example), or in isolated populations such as the Devils hole pupfish (Cyprinodon diabolis). Changes by "microevolution" may or may not be rapid - it depends on random chance and changes in the statistical frequency of alleles through genetic drift. Which, btw, could just as easily eliminate alleles as increase their frequency. Besides which, variability as you suggest - which depends on mutation rates - still has to become fixed. To get the incredible diversity of, for example, cat kinds from a single pair of "essential cats" would require not only a mutation rate thousands of times greater than is currently observed, but also true cladogenesis events occurring many orders of magnitude more often than can even be conceived. If things occurred that rapidly, we should be observing brand new species of vertebrates, for example, at the rate of dozens a year.

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How about the interesting feature in the hominid fossil record for the abrupt disappearance of homo sapiens between 80 000 and 40 000 years ago (the dates are arbitrary.)? Incidentally, the other article I mentioned in "reordering of fossils" topic could use the Cambrian explosion as an example. The other model (I'm not saying that it's correct) explains the lack of larger animals by saying they were wiped out completely then (except for those on the ark) and all the fossil evidence for them before the flood. Thus, after they get off the ark, there is then fossil evidence for them.

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I'll look at the other thread, but neither scenario makes any sense. In the first place, why do you claim the dates are "arbitrary"? In the second, it seems pretty convenient that all traces of "larger animals" were erased in the Cambrian Flood. If that's the case, and only those animals on the ark left to make fossils after debarking, what's the deal on amphibians in the Ordovician but not Cambrian (i.e., contiguous with the weird beasties that must have been on the ark as well in those layers), the first reptiles in the Pennsylvanian but not the Cambrian, the first mammals in the Triassic but not any of the lower levels. (Creationists really should use the Permian-Triassic extinction instead of the Cambrian radiation). Finally, the whole shebang begs the question of all those pre-Cambrian fossils (especially the Vendian fossilary, and those 3.5 gya stromatoliths).

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Mitochondrial studies of women from around the world suggested that the last common ancestor of modern man (actually women) appeared within the last 200,000 years, which is much more recent than previously thought.

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From the perspective of male genetics, scientists have examined a gene (ZFY), which being on the Y chromosome, is passed down only from father to son. 38 men were chosen from around the world. Scientists determined the actual genetic sequence in each man for this gene, which is 729 base pairs long. To their surprise, all men had identical genetic sequences (over 27,000 base pairs analyzed). Scientists have calculated the most probable date for the last common ancestor of modern man, given the sequence diversity from modern apes. Using two different models this date is either 270,000 or 27,000 years ago (note that these dates are the suggested maximum figures).

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Okay, so we're somewhere around three quarters of a million years as the date of your flood? How does this square with the 4000 years the YECs keep babbling about?How about the evidence for the bottleneck?

Oh well, as long as all we're doing is quoting somebody else's website, try this as a rebuttal to your amen.org citation:

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Coal: In Place or Transported?

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While modern geology recognizes both in place (autochthonous) and transported (allochthonous) coals, the conclusion shared by all diluvial "models" of coal formation is that all coals originated from vegetation that was transported via floodwaters from the place where it grew to the place where it was buried. Obviously there is not enought time during the one year-flood for peat to accumulate autochthonously, which in the modern world happens at a rates of only a few mm/yr.

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However, careful observation of the root systems and attached rootlets ('stigmaria') attached to upright lycopod trunks at the base of many Carboniferous (and later) coals show that they grew on site and were not "washed into place" from some other location (Gastaldo 1984, 1999). In situ trunks and deep root traces are known from the Devonian (Driese et al. 1997; Retallack 1997) and all subsequent geologic periods, but not from earlier periods. Several multi-level buried 'fossil forests' have been documented also, some of which are associated with coals and some which are not. Some examples include 3 sand-buried Eospermatopteris stump horizons with roots penetrating underlying mudstones documented in the Devonian Catskill 'delta' in eastern New York (Banks et al. 1985, p. 133), 10 successive conifer forests from the mid-Jurassic of Curio Bay New Zealand (Pole 2001) and several others from Kawhia Harbour (Thorn 2001), a buried Cretaceous conifer/angiosperm forest with roots penetrating underlying paleosols from Alexander Island, Antarctica (e.g. Cantrill and Lang 2001).

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The root system of the lycopod trees which are the dominant trees in most paleozoic coals consisted of four main axes which departed the base of the trunk and dichotomozed several times. These root systems intertwined with the root systems of other trees, forming a giant network of roots. The underground portion of the roots bear helically-arranged "rootlets," giving stigmaria a bottle-brush-like 3-dimensional structure. In many cases, these root systems can be seen branching outward from upright trunks, and the delicate appendages extend outward from these roots into the surrounding sediments. Gastaldo (1984) states "The proximal axial systems may depart the base at angles up to 30 degrees and the more distal axes commonly cross-cut bedding at angles of 10 degrees or more. This provides for an intertwining of axes at multiple levels, rather than the generally viewed concept of intertwining along a single plane or adjacent planes. The appendages ('rootlets') develop perpendicular to the main axial system and also cross-cut bedding where bedding is preserved." These lycopod trees in Carboniferous coals typically occur alongside plants such as the sphenopsids (Calamites, for instace), pteropsids (which includes true ferns and pteridosperms, an extinct form of seed fern), and Cordaitales. In situ Calamites have been documented in association with lycopods.

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Gastaldo (1984) evaluated the "floating forest" hypothesis favored by YECs such as Scheven, Wieland (1996), and others, and found it wanting. For instance, their is no evidence of soft-sediment deformation that would be expected if the root systems sank into the freshly-deposited underlying sediment. The delicate rootlets are spread outward in a radial pattern, cross-cutting the encasing lithology and bedding (where preserved) rather than deformed around the larger root axes. Nor are their any flame casts or mud diapers in the base of the coal which would occur as the floating mats sank onto the underlying sediments. Gastaldo's (1984) review concluded:

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"That the stigmarian axial systems embedded within the underclays (paleosols) of coals represent stands of lycopods in non-peat and peat accumulating environments is unquestionable. The assertion that these lycopods were abiotically, vertically emplaced from a floating habit cannot be supported by the disposition of the axial systems or the sedimentary structures accompanying them."

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Gastaldo (1999) critiques other evidence offered in support of allochthony, and presents further evidence for autochthony :

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"When evaluating both Mesozoic and Cenozoic coals, particularly lignites or brown coals, ample empirical evidence has been presented not only for root penetration within the weakly developed soil beneath the coal, but also for extensive, in situ, standing forests within the coals (e.g. Mossbrugger et al., 1994). The distribution of these trees (below, within and above coal seams) . . . is another criterion for recognizing autochthonous coals. Paleoecological studies from Carboniferous strata also have demonstrated that such assemblages conform to expected tree distributions in modern forests [refs omitted -ps]. In addition, the presence of multiple, stratified standing forests within coal-bearing sequences, one atop another, each with its own incipient soil horizon penetrated by underground stigmarian axes at the same site, provides unequivocal evidence for their autochthonous nature" (p. 148-149).

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Quoted section from Coal deposits: evidence for the Noah's Flood "model"? Citations referenced can be found at the bottom of the article. Thanks Patrick!Basically, your floating mat theory doesn't hold water (sorry, couldn't resist the pun) because of other associated features present in almost every coal bed in the world. Some of the features are geologic, some represent bioturbation, cross-bedded fossils like trees, existing paleosols below and between beds, and numerous other features.Now that we've gotten that out of the way, would you care to answer my question? Thanks.