What would be fascinating, Alexander says, would be if you had a situation where you could trace this Y-chromosome Adam to a similar time as the mitochondrial Eve, as this would suggest some quick or sudden population expansion—the kind that comes when a species moves into new territory. That's too bad; it would have been a whale of a tale. monthName = 'September' // -->. '0':'')+lm_month; Or they only had sons, which wouldn’t have passed on their mitochondrial DNA. as is the case in ALL THINGS attributed to god if … The animal will sometimes die, but occasionally environmental factors allow it to survive with the gene no longer active. And, if the mutations affecting mtDNA had indeed occurred at constant rates, then the mtDNA could serve as a molecular clock for timing evolutionary events and reconstructing the evolutionary history of extant species. He has crossed the Sahara Desert, floated down the Amazon River and explored in more than 50 countries. This makes it relatively easy to analyze. One study found that mutation rates in mitochondrial DNA were eighteen times higher than previous estimates (see Parsons, et al., 1997). If humans received mitochondrial DNA only from their mothers, then researchers could “map” a family tree using that information. Morris, Andrew A. M., and Robert N. Lightowlers (2000), “Can Paternal mtDNA be Inherited?,” The Lancet, 355:1290-1291, April 15. A year later, that “speculation” became a major Newsweek production titled, “The Search for Adam and Eve” (Tierney, et al., 1988). No, Virginia, Science hasn't debunked Adam. There inferences will now have to be reconsidered” (1999, 286:2525). Although there may not have been a literal Adam and Eve, our species has a “genetic Adam” and a “mitochondrial Eve.” Our genetic Adam was … For decades, evolutionists had been trying to determine the specific geographical origin of humans—whether we all came from one specific locale, or whether there were many small pockets of people placed around the globe. Feedback | We now know that the two key assumptions behind the data used to establish the existence of “mitochondrial Eve” are not just flawed, but wrong. Lewin, Roger (1987), “The Unmasking of Mitochondrial Eve,” Science, 238:24-26, October 2. A word of explanation is in order. By examining 1,600 sperm whales across the world, researchers surmised … She, then, would be the only woman out of all the women living in her day to have a daughter in every generation till the present. Working from the assumption that mtDNA is passed to the progeny only by the mother, Dr. Cann and her coworkers believed that each new cell should contain copies of only the egg’s mitochondria. The edition sold a record number of copies. Tierney, John, Lynda Wright, and Karen Springen (1988), “The Search for Adam and Eve,” Newsweek, pp. But it was not forbidden fruit that caused her demise this time around. Having concluded that the African group was the oldest, Dr. Cann and her colleagues wanted to find out just how old the group might be. Perhaps some of her contemporaries had no surviving children. Or, her genetic takeover could have been just the result of a slow expansion of her progeny over many generations. Scientists—who used this concept to determine the age of mitochondrial Eve—refer to this proposed mutation rate as a “molecular clock.” One group of researchers described the process as follows: It sounds good in theory, but the actual facts tell an entirely different story. monthName = 'February' To the researchers, the presence of Africans among non-Africans meant an African common ancestor for the non-African branches, which, likewise, meant an African common ancestor for both branches. More differences mean more mutations, and hence more time to accumulate those changes. '0':'')+lm_second; “We’re not saying that there was just one female swimming around the ocean at that time and suddenly all these sperm whales arose from her,” Alana Alexander, a postdoctoral researcher at the Biodiversity Institute at the University of Kansas and lead author of the study, tells Smithsonian.com. Usually, female sperm whales are more sedentary, tending to stick to smaller parts of the ocean than males, says Alexander. To do this, they used what is known as a “molecular clock” that, in this case, was based on mutations in the mtDNA. Continue Each individual human has one set of mitochondrial genes, from their mother, and two sets of genes in the cell nucleus, one from each parent.