The pro-replacement "spin" is annoying. Stuff like "Is Eve older than we thought? by Sanjida O'Connell 15th April 1999" (at the "in reply to" link) is the headline for an article that sez that there was
no mitochondrial "Eve". And the devotion to the baseless mtDNA "studies" leads to other nonsense conclusions:
A new mystery evolves on trail of early humans
by Emily Sohn
06/26/2000
New studies of the Y chromosome, the bundle of DNA that distinguishes men from women, suggest that current branches of the human family tree derive from a male ancestor who may have lived only 50,000 years ago, scientists reported last week in the Proceedings of the National Academy of Sciences. Previous studies, based on a type of DNA passed on only by women, indicate that the most recent common female ancestor, or "Eve," lived at least 150,000 years ago... "Something happened to the record 50,000 to 60,000 years ago," said Peter Oefner, a biologist at the Stanford DNA Sequencing and Technology Center and one of the authors of the study. "We started at ground zero again." ...The new evidence, based on analysis of the DNA of 72 males from 46 populations, is striking, Dr. Oefner said... Dr. Oefner is quick to warn that... [t]he average estimate coming out of the new data is 50,000 years, he said, but that male could have lived anywhere from 40,000 to 140,000 years ago.
Modern multiregionalists still believe that there was a common African origin, but place it millions of years ago. The replacement camp sez that the previous hominids originated in Africa and spread out from there, but that for some reason a master race, er, AMH, with superior characteristics, skills, and weapons, migrated out of Africa 50 to 100 thousand years ago and took over everything, driving earlier hominids into extinction by about 20,000 years ago (at the latest). Since the continental shelf has been exposed plenty of the past 2 million years (at least it has been in the gradualist models, and due to glaciation), much of the formerly habitable land has never given up its fossils. And that 2 million year period is precisely when Erectus has been loping around.
Did Viruses Make Us Human?
by Kathy A. Svitil
The human genome is littered with scraps of DNA that serve no clearly defined function. Scientists believe these transposons -- so called because they can jump around the chromosomes -- were acquired millions or billions of years ago, when viruses inserted their own DNA into that of the host. Until recently, transposons were regarded as genetic junk. But when geneticists discovered that the junk accounts for nearly half of our genome, "people started to seriously consider that they might contribute to evolution," McDonald says... A single HERV-K element is present in humans but not in chimps. Judging from other measures of genetic change, this transposon appeared 6 million years ago, exactly when humans and chimps went their separate ways. McDonald hypothesizes that bits of viral DNA might have inserted themselves and altered functional genes, modifying the proteins they make, or the viral bits might have incited a reshuffling of the primate genome.
There was no such event, no going "their separate ways". With whom did the 23 chromosome pair newly human freak mate and reproduce? This genetic discontinuity results from a false assumption, and leads to speculation like that above.
About 30 years ago a book
The Descent of Woman by the following author failed to make a case against the savannah theory of hominid evolution. The book linked below continues that struggle. The Aquatic Ape theory is at least somewhat respectible now, but there's so much in the way of politics involved that I can't get fired up about it. The info about the baboon virus was in this book (previously I'd been unaware of it). Quote follows the URL.
The Scars of Evolution
by Elaine Morgan
"The most remarkable aspect of Todaro's discovery emerged when he examined Homo Sapiens for the 'baboon marker'. It was not there... Todaro drew one firm conclusion. 'The ancestors of man did not develop in a geographical area where they would have been in contact with the baboon. I would argue that the data we are presenting imply a non-African origin of man millions of years ago.'"
Morgan obviously uses this to buttress her Aquatic Ape theory, since the area where (in her view) hominids became Homo Sapiens was in a supposedly isolated chunk of eastern Africa, temporarily separated from the mainland by open water. It was a nice safe place, free of predators, and the hominids just lucked out when the land split. IOW, it's just an anachronistic fantasyland.
The same biological characteristics of humans used to suggest a coastal origin have also been pointed out as mitigating against a natural origin for Homo Sapiens. In other words, all those ideas that have extraterrestrials or intelligent dinosaurs manipulating DNA to produce our ancestors, grow in the same soil. This is not meant to belittle or condemn any or all of these three ideas through association with the others.