An international team of researchers have discovered a new gene that helps explain how humans evolved from chimpanzees. Scientists say the gene – called miR-941 – appears to have played a crucial role in human brain development and may shed light on how we learned to use tools and language. Researchers say it is the first time that a new gene – carried only by humans and not by apes – has been shown to have a specific function within the human body. A team at the University of Edinburgh compared the human genome to 11 other species of mammals, including chimpanzees, gorillas, mouse and rat, to find the differences between them. The results, published in Nature Communications, showed that the gene – miR-941 – is unique to humans. The researchers say that it emerged between six and one million years ago, after humans had evolved from apes. The gene is highly active in two areas of the brain that control our decision making and language abilities. The study suggests it could have a role in the advanced brain functions that make us human. It is known that most differences between species occur as a result of changes to existing genes, or the duplication and deletion of genes. But scientists say this gene emerged fully functional out of non-coding genetic material, previously termed "junk DNA", in a startlingly brief interval of evolutionary time. Until now, it has been remarkably difficult to see this process in action. Read more at: http://phys.org/news/2012-11-brain-gene-edge-apes.html#jCp
I'm not sure if geneticists understand the implications of the bundling of genes into chromosomes, but certainly the remarkable distinction between modern humans and modern apes is the merge of two chromosomes into one, at chromosome II: Please Register or Log in to view the hidden image! That's human, chimp, gorilla and orangutan, from left to right in each set. It's mind-boggling to think a gene has been isolated which is associated with a high level function like speech. Imagine the thousands (or perhaps millions) of lower level gene expressions that have to take place to convert the high-level trait into the countless lower level structures that make something like speech possible. And much of this is high mystery--like the brain tissue formation that will endow a person with speech, or how that relates to the mind that arises in that particular brain.
Great you understand and you can challenge . Could you describe what have merged at the chromosome 11 are you saying there was a fusion ?
This has been discussed in previous threads. Yes, there was an end-to end fusion of two chromosomes (i.e the same genes on those two chromosomes in the other apes are in the single chromosome of Homo).
Here's the paper, which I don't pretend to understand in detail: Evolution of the human-specific microRNA miR-941 But the press release by the University of Edinburgh is terrible. It smells of deliberate sensationalism. It also says that the work was by "A team at the University of Edinburgh", which doesn't seem to correspond with the fact that all but one of the paper's 13 authors are from China, mostly from the CAS Key Laboratory of Computational Biology, Shanghai. The sole exception is the seventh author, Dr Martin Taylor, who is quoted in the press release saying things he might regret when requoted by creationists. The questionable convention of distinguishing humans from apes is annoying. Conversationally, 'apes' can mean "lesser apes and all Homonidae except Homo sapiens", but scientifically it seems silly to make that exception. And why use the obsolete term "junk DNA"?
Yeah, not the same thing. This thread is about a paper published on October 23 on the evolution of a specific gene, miR-941.
MIR941-1 is not a gene in the traditional since, this tiny sections of DNA of only ~117 base pairs codes for a microRNA that regulates specific gene expression, in this pseudo-genes case its appears highly important in human brains development and thus in the evolution of human intelligence, still more research is needed to verify this theory and to further clarify the role of MIR941-1. Source: http://www.ncbi.nlm.nih.gov/pubmed/23093182
"But scientists say this gene emerged fully functional out of non-coding genetic material, previously termed "junk DNA", in a startlingly brief interval of evolutionary time. Until now, it has been remarkably difficult to see this process in action." This will give more credit to those writers like Lou Baldin who claim that ALIENS have made several specific amendments to the human genome over the last few million years. A kind of non-religious intelligent design, so to speak. I suppose this idea was first aired by Kubrick's 2001 A Space Odyssey.
Scientist don't say that: 'In the human and macaque genomes, the miR-941 precursor region are composed of tandem repeats displaying greater interspecies than intraspecies variation, indicating rapid locus evolution (Supplementary Fig. S2a-e). Correspondingly, almost the entire repeat region is lost in the chimpanzee genome (Fig. 2a). One of the repeat copies present in the macaque genome differs from the rest and more closely resembles the human variant of the tandem repeats. It is therefore likely that tandem repeats present in the human genome were derived from this repeat variant, which has undergone copy number expansion and replaced other repeat variants in the human lineage (Supplementary Fig. S2f). It takes two copies of the human version of tandem repeats to form pre-miR-941, with the apex of the precursor stem loop structure coinciding with the boundary between repeats (Supplementary Fig. S2g). As a consequence, corresponding genomic regions in chimpanzees and macaque could not form stable miRNA precursor hairpins (Fig. 2a,b). To confirm the validity of the reference genome sequences, we amplified and sequenced the pre-miR-941 locus in one human, eight chimpanzees and six rhesus macaques (Supplementary Table S3). The sequences matched the reference genome sequences (Supplementary Fig. S3). These results demonstrate that miR-941 precursor sequence has evolved in humans, most likely after the human–chimpanzee split, through tandem repeat replacement and expansion.' What this means is the mir-941 evolved from available genetic material in the common chromosome that was present in our primate ancestors (although lost in chimps, the common human-chimp ancestor clearly had this miR-941 precursor sequence). So no this one was not inserted into proto-humans by the monolith, it existed before, its just in humans it evolved into a fully functional microRNA.
Indeed. The speech center is unique to humans, although not to modern humans, since the Neanderthal brain also has it. Anthropologists say that the complex, coordinated activities human clans were engaged in 70KYA could not possibly have taken place without language. The first successful migration out of Africa occurred shortly after that, 60KYA, and it's been said that an endeavor of that nature and that scope, learning to survive in a new environment, could not have happened without language. Of course this doesn't mean that language can't be much older than that, but it tells us that it goes back at least 70K years. If indeed there was only one original language and all others evolved from it, this explains how they could have diverged so much that the relationships are no longer discernable. The oldest relationship we have found is between the Yeniseian language of Siberia and the Na-Dene languages of North America (Navajo, Tlingit, etc.), which goes back 15K years to the migration out of Asia. The similarities are so vague that not all linguists even accept the relationship. So you can imagine what it would be like trying to find the commonality between, say, the Indo-European family and the Austronesian family. This is just as stupid as distinguishing "humans" from "animals." What are we then? Plants? Algae? Fungi? Bacteria? Archaea? There are only six kingdoms of organisms. "Apes" is a clade, and we are incontrovertibly members of it. We're all hominoids: apes. Hominoids and Old World monkeys make up the clade of Catarrhini. Catarhinni and Platyrhinni (New World Monkeys) make up the clade of Simiiformes. Simmiiformes and tarsiers make up the clade of Haplorhinni. Haplorhinni and Stepsyrhinni (lemurs and lorises) make up the order of Primates.
In case you didn't notice, I was talking about the immediate two preceding threads to my post, by Aqueous-ID and Arauca, pertaining to the fusion of non-Homo primate chromosomes, which are found fused in the Homo sapiens. While it might appear to be a tangential matter, it is related in that the fusion of those chromosomes appear to separate us from the other apes, likely more so than just that single gene of the original thread.
but I bet taking out another gene would make us a lemur or any primate out there down the evolution chain. We are 90% gene similar to chimps, 80% to cows, 75% to mice, 60% to fruit flies...
