Published: 18 April 2008 (GMT+10)
The headline in the February issue of Scientific American read ‘Lovers, not fighters’.1 In the article, a team of evolutionary geneticists is said to have discovered the signature of Homo erectus in the human genome. Publishing its results in the January issue of Genetics, the University of Arizona research team believes it found evidence of interbreeding between modern humans and Homo erectus.
Focusing on the X chromosome, the geneticists utilized molecular clock analysis to date certain regions of the genome that reflect the genetic diversity of human history. Based on certain genetic fingerprints, the scientists believe that modern humans and Homo erectus may have interbred as long ago as 2.3 million years.
Competing creationist perspectives
Though this is the first study of its kind, this indirect genetic evidence challenges old-earth creation views, such as those of Dr. Hugh Ross of Reasons to Believe (RTB). Such old-earth creationists argue that Adam and Eve were real, historical individuals specially created about 50,000 years ago, possibly up to 100,000 years ago. Therefore, in order to maintain any semblance of consistency with the Genesis genealogies, they propose that Homo erectus was a man-like animal created before Adam and Eve. On the other hand, young-earth creationists generally posit that Homo erectus was a fully human descendant of Adam and Eve—see Turkana boy getting past the propaganda and Putting chimpanzees, hominids, and humans in their proper place.
Thus, old-earth creationists would not expect any genetic evidence for interbreeding between Homo erectus and Homo sapiens sapiens, while we are encouraged when such conclusions are drawn even by evolutionary scientists. Though it is premature to make any conclusive scientific judgments, the initial genetic evidence seems to strengthen the view that Homo erectus and modern humans were indeed the same species.
Direct DNA analysis
If we could obtain direct Homo erectus DNA sequences, then more conclusive inferences could be drawn from the data. Though old-earth creationists, such as RTB, believe Homo erectus specimens are likely far too old to extract actual DNA sequences,2 young-earth creationists posit much younger ages for Homo erectus. As a result, we would not be surprised if some Homo erectus fossils possess DNA for genetic analysis. There is a precedent for such a view, since many scientists were initially incredulous before obtaining legitimate DNA samples from ‘ancient’ Neanderthals.
This would be a great field for creation paleontologists and geneticists to conduct top level science without the constraint of long-age thinking. Perhaps another shock could be sent throughout the scientific community similar to the discovery of supposedly 68-million-year-old blood cells, protein sequences, and actual, soft, flexible tissue in a T. Rex fossil.
Modern humans, Homo erectus, and moral depravity
Dr. Fuz Rana, of RTB, raised a provocative issue regarding the implications of potential interbreeding between Homo erectus and modern humans. In his February 28th ‘Science News Flash’ podcast,3 Dr. Rana stated that the RTB model predicts that Homoerectus and modern humans should be biologically and behaviorally distinct from one another. But he then adds the caveat that, due to moral depravity, modern humans may have in fact interbred with the Homo erectus ‘animals’. He cites Old Testament warnings against bestiality and the depravity of mankind at the Babel dispersion.
However, this raises a number of serious questions. If they could interbreed and produce fertile offspring, then wouldn’t they be the same biological species, according to the modern-day definition? Even a number of evolutionary anthropologists, such as Milford Wolpoff and Alan Thorne, believe Homo erectus and modern humans should be classified as the same species. He finishes by stating that genetic evidence of Homo erectus and modern human interbreeding would be uncomfortable for the RTB model, but not lethal. This seems to contradict RTB’s public position that Homo erectus and modern humans are definitively distinct from one another, both biologically and anatomically. These statements appear to make the RTB model unfalsifiable in this aspect. What evidence could ever contradict their human origins model? Even definitive anatomical evidence of interbreeding between modern humans and so-called ‘hominids’ (which already exists4 ) could be dismissed as mere evidence of bestiality, despite the fact that by definition, humans cannot interbreed with other species.
According to various sources,5 the old Soviet Union’s top animal-breeding scientist, Ilya Ivanov, attempted multiple hybridization experiments between monkeys and humans, as well as chimpanzees and humans. All attempts failed.
Molecular clock inaccuracies
Dr. Rana does raise a valid point in questioning the accuracy of molecular clock analysis. Though RTB accepts the validity of most long-age dating methods, it does realize that molecular clock dating is often unreliable, based on a number of assumptions, and at odds with fossil dates. The young-earth community is highly skeptical of molecular clock dating—obviously, because it contradicts the Bible, but also in part due to numerous acknowledged discrepancies with the fossil record and present-day mutational rates—see A shrinking date for Eve . This is why genetic research based solely on molecular clock analysis must be critically analyzed.6
Increased genetic testing is encouraged by the creation science community. The results discussed here are preliminary and don’t provide concrete resolutions, but even at this preliminary stage, the credibility of the young-earth model of human origins has been further enhanced.
- Whitfield, John, Lovers, not fighters? Scientific American. 2008. Return to text.
- Ross, Hugh. Creation as Science. Navpress 2006. p. 153. Return to text.
- http://reasons.org/ Return to text.
- Evolutionary anthropologists have identified several Neanderthal/modern human fossil hybrids. In addition, Marvin Lubenow, renowned creationist anthropologist, has documented at least 62 fossil individuals that bear strong Homo erectus morphology, as recent as 12,000 years ago. Return to text.
- Grigg, Russell. Stalin’s ape-man superwarriors. Creation 29(1): 32–33. December 2006-February 2007. Return to text.
- However, they do not dispute the high ‘ages’ in general placed on erectus, placing them well before RTB’s dates for Adam. This is the very reason why RTB is compelled to classify such specimens as non-human. Return to text.