'Junk DNA' Genomics Human evolution Intelligent Design

Humans may have only 19,000 coding genes

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DNA image)/k_e_n, Fotolia

And we are not sure which ones they are. From ScienceDaily:

Research Centre (CNIO) reveals that up to 20% of genes classified as coding (those that produce the proteins that are the building blocks of all living things) may not be coding after all because they have characteristics that are typical of non-coding or pseudogenes (obsolete coding genes).

They don’t mean “junk DNA,” do they? Not this again.

The work once again highlights doubts about the number of real genes present in human cells 15 years after the sequencing the human genome. Although the most recent data indicates that the number of genes encoding human proteins could exceed 20,000, Federico Abascal, of the Wellcome Trust Sanger Institute in the United Kingdom and first author of the work, states: “Our evidence suggests that humans may only have 19,000 coding genes, but we still do not know which 19,000 genes are.”

For his part, David Juan, of the Pompeu Fabra University and participant in the study, reiterates the importance of these results: “Surprisingly, some of these unusual genes have been well studied and have more than 100 scientific publications based on the assumption that the gene produces a protein. ”

This study suggests that there is still a large amount of uncertainty, since the final number of coding genes could 2,000 more or 2,000 fewer than it is now. The human proteome still requires much work, especially given its importance to the medical community. Paper. (open access) – Federico Abascal, David Juan, Irwin Jungreis, Laura Martinez, Maria Rigau, Jose Manuel Rodriguez, Jesus Vazquez, Michael L Tress. Loose ends: almost one in five human genes still have unresolved coding status. Nucleic Acids Research, 2018; 46 (14): 7070 DOI: 10.1093/nar/gky587 More.

Been a while since we’ve heard much about humans as the 98% or 99% chimpanzee. If the human genome is this fuzzy how would we know? And doubtless, things have gotten more complex.

See also: Human genome shrinks again, lower than projected nematode worm (2014)

4 Replies to “Humans may have only 19,000 coding genes

  1. 1
    ET says:

    It’s the number of different proteins that really matter with respect to the number of genes

  2. 2
    bornagain77 says:

    News asks,

    “Been a while since we’ve heard much about humans as the 98% or 99% chimpanzee. If the human genome is this fuzzy how would we know?”

    And ET adds,

    “It’s the number of different proteins that really matter with respect to the number of genes”

    Indeed, Dawkins’s entire concept of the ‘selfish gene’, (i.e. the modern synthesis, neo-Darwinism) is now dead.

    Gene previously linked to obesity is unrelated – June 29, 2015
    Excerpt: … in the real world of careful analysis, scientists are just not finding the “genes” that the headline writers need. British geneticist Steve Jones points out that most human traits are influenced by so many genes that there is no likely systematic cause and effect:
    “We know of more than 50 different genes associated with height … That has not percolated into the public mind, as the Google search for “scientists find the gene for” shows. The three letter word for — the gene FOR something — is the most dangerous word in genetics.”
    And the craze is not harmless, he warns. …
    http://www.uncommondescent.com.....unrelated/

    What If (Almost) Every Gene Affects (Almost) Everything? – JUN 16, 2017
    Excerpt: If you told a modern geneticist that a complex trait—whether a physical characteristic like height or weight, or the risk of a disease like cancer or schizophrenia—was the work of just 15 genes, they’d probably laugh. It’s now thought that such traits are the work of thousands of genetic variants, working in concert. The vast majority of them have only tiny effects, but together, they can dramatically shape our bodies and our health. They’re weak individually, but powerful en masse.
    https://www.theatlantic.com/science/archive/2017/06/its-like-all-connected-man/530532/

    Theory Suggests That All Genes Affect Every Complex Trait – June 20, 2018
    Excerpt: Mutations of a single gene are behind sickle cell anemia, for instance, and mutations in another are behind cystic fibrosis.
    But unfortunately for those who like things simple, these conditions are the exceptions. The roots of many traits, from how tall you are to your susceptibility to schizophrenia, are far more tangled. In fact, they may be so complex that almost the entire genome may be involved in some way,,,
    One very early genetic mapping study in 1999 suggested that “a large number of loci (perhaps > than 15)” might contribute to autism risk, recalled Jonathan Pritchard, now a geneticist at Stanford University. “That’s a lot!” he remembered thinking when the paper came out.
    Over the years, however, what scientists might consider “a lot” in this context has quietly inflated. Last June, Pritchard and his Stanford colleagues Evan Boyle and Yang Li (now at the University of Chicago) published a paper about this in Cell that immediately sparked controversy, although it also had many people nodding in cautious agreement. The authors described what they called the “omnigenic” model of complex traits. Drawing on GWAS analyses of three diseases, they concluded that in the cell types that are relevant to a disease, it appears that not 15, not 100, but essentially all genes contribute to the condition. The authors suggested that for some traits, “multiple” loci could mean more than 100,000.
    https://www.quantamagazine.org/omnigenic-model-suggests-that-all-genes-affect-every-complex-trait-20180620/

    The next evolutionary synthesis: from Lamarck and Darwin to genomic variation and systems biology – Bard – 2011
    Excerpt: If more than about three genes (nature unspecified) underpin a phenotype, the mathematics of population genetics, while qualitatively analyzable, requires too many unknown parameters to make quantitatively testable predictions [6]. The inadequacy of this approach is demonstrated by illustrations of the molecular pathways that generates traits [7]: the network underpinning something as simple as growth may have forty or fifty participating proteins whose production involves perhaps twice as many DNA sequences, if one includes enhancers, splice variants etc. Theoretical genetics simply cannot handle this level of complexity, let alone analyse the effects of mutation..
    http://www.biosignaling.com/co.....X-9-30.pdf

    Gene Pleiotropy Roadblocks Evolution by Jeffrey P. Tomkins, Ph.D. – Dec. 8, 2016
    Excerpt: Before the advent of modern molecular biology, scientists defined a gene as a single unit of inheritance. If a gene was found to influence multiple externally visible traits, it was said to be pleiotropic—a term first used in 1910.2 During this early period of genetic discovery, pleiotropy was considered to be quite rare because scientists assumed most genes only possessed a single function—a simplistic idea that remained popular throughout most of the 20th century. However, as our understanding of genetics grew through DNA science, it became clear that genes operate in complex interconnected networks. Furthermore, individual genes produce multiple variants of end products with different effects through a variety of intricate mechanisms.2,3 Taken together, these discoveries show that pleiotropy is a common feature of nearly every gene.,,,
    The pleiotropy evolution problem is widely known among secular geneticists, but rarely discussed in the popular media. In this new research report, the authors state, “Many studies have provided evidence for the ability of pleiotropy to constrain gene evolution.”,,,
    “Our study provided supportive evidence that pleiotropy constraints the evolution of transcription factors (Tfs).”,,,
    The authors state, “We showed that highly pleiotropic genes are more likely to be associated with a disease phenotype.”,,,
    http://www.icr.org/article/9747

    Why the ‘Gene’ Concept Holds Back Evolutionary Thinking – James Shapiro – 11/30/2012
    Excerpt: The Century of the Gene. In a 1948 Scientific American article, soon-to-be Nobel Laureate George Beadle wrote: “genes are the basic units of all living things.”,,,
    This notion of the genome as a collection of discrete gene units prevailed when the neo-Darwinian “Modern Synthesis” emerged in the pre-DNA 1940s. Some prominent theorists even proposed that evolution could be defined simply as a change over time in the frequencies of different gene forms in a population.,,,
    The basic issue is that molecular genetics has made it impossible to provide a consistent, or even useful, definition of the term “gene.” In March 2009, I attended a workshop at the Santa Fe Institute entitled “Complexity of the Gene Concept.” Although we had a lot of smart people around the table, we failed as a group to agree on a clear meaning for the term.
    The modern concept of the genome has no basic units. It has literally become “systems all the way down.” There are piecemeal coding sequences, expression signals, splicing signals, regulatory signals, epigenetic formatting signals, and many other “DNA elements” (to use the neutral ENCODE terminology) that participate in the multiple functions involved in genome expression, replication, transmission, repair and evolution.,,,
    Conventional thinkers may claim that molecular data only add details to a well-established evolutionary paradigm. But the diehard defenders of orthodoxy in evolutionary biology are grievously mistaken in their stubbornness. DNA and molecular genetics have brought us to a fundamentally new conceptual understanding of genomes, how they are organized and how they function.
    http://www.huffingtonpost.com/.....07245.html

    Duality in the human genome – Nov. 28, 2014
    Excerpt: The results show that most genes can occur in many different forms within a population: On average, about 250 different forms of each gene exist. The researchers found around four million different gene forms just in the 400 or so genomes they analysed. This figure is certain to increase as more human genomes are examined. More than 85 percent of all genes have no predominant form which occurs in more than half of all individuals. This enormous diversity means that over half of all genes in an individual, around 9,000 of 17,500, occur uniquely in that one person – and are therefore individual in the truest sense of the word.
    The gene, as we imagined it, exists only in exceptional cases. “We need to fundamentally rethink the view of genes that every schoolchild has learned since Gregor Mendel’s time.,,,
    According to the researchers, mutations of genes are not randomly distributed between the parental chromosomes. They found that 60 percent of mutations affect the same chromosome set and 40 percent both sets. Scientists refer to these as cis and trans mutations, respectively. Evidently, an organism must have more cis mutations, where the second gene form remains intact. “It’s amazing how precisely the 60:40 ratio is maintained. It occurs in the genome of every individual – almost like a magic formula,” says Hoehe.
    http://medicalxpress.com/news/.....enome.html

    Multiple haplotype-resolved genomes reveal population patterns of gene and protein diplotypes – 26 November 2014
    Excerpt Discussion: Our global view of haplotype/diplotype diversity in relation to population size suggests that current efforts are still far from capturing the majority of gene forms and that saturation may not even be achievable. The concept of a predominant, ‘wild-type’ form of ‘the’ gene appears obsolete for over 85% of genes, challenging traditional ‘Mendelian’ views. This highlights the need for an expansion of current concepts of ‘the’ gene^29, along with the development of appropriate documentation and language. The enormous diversity of haploid and diploid gene forms raises fundamental questions concerning the relationships between sequence(s), structure(s) and function(s)^21
    http://www.nature.com/ncomms/2.....s6569.html

    Why the ‘Gene’ Concept Holds Back Evolutionary Thinking – James Shapiro – 11/30/2012
    Excerpt: The Century of the Gene. In a 1948 Scientific American article, soon-to-be Nobel Laureate George Beadle wrote: “genes are the basic units of all living things.”,,,
    This notion of the genome as a collection of discrete gene units prevailed when the neo-Darwinian “Modern Synthesis” emerged in the pre-DNA 1940s. Some prominent theorists even proposed that evolution could be defined simply as a change over time in the frequencies of different gene forms in a population.,,,
    The basic issue is that molecular genetics has made it impossible to provide a consistent, or even useful, definition of the term “gene.” In March 2009, I attended a workshop at the Santa Fe Institute entitled “Complexity of the Gene Concept.” Although we had a lot of smart people around the table, we failed as a group to agree on a clear meaning for the term.
    The modern concept of the genome has no basic units. It has literally become “systems all the way down.” There are piecemeal coding sequences, expression signals, splicing signals, regulatory signals, epigenetic formatting signals, and many other “DNA elements” (to use the neutral ENCODE terminology) that participate in the multiple functions involved in genome expression, replication, transmission, repair and evolution.,,,
    Conventional thinkers may claim that molecular data only add details to a well-established evolutionary paradigm. But the diehard defenders of orthodoxy in evolutionary biology are grievously mistaken in their stubbornness. DNA and molecular genetics have brought us to a fundamentally new conceptual understanding of genomes, how they are organized and how they function.
    http://www.huffingtonpost.com/.....07245.html

  3. 3
    bornagain77 says:

    further notes:

    On Human Origins: Is Our Genome Full of Junk DNA? Pt 2. – Richard Sternberg PhD. Evolutionary Biology – podcast
    Excerpt: “Here’s the interesting thing, when you look at the protein coding sequences that you have in your cell what you find is that they are nearly identical to the protein coding sequences of a dog, of a carp, of a fruit fly, of a nematode. They are virtually the same and they are interchangeable. You can knock out a gene that encodes a protein for an inner ear bone in say a mouse. This has been done. And then you can take a protein that is similar to it but from a fruit fly. And fruit flies aren’t vertebrates and they certainly are not mammals., so they don’t have inner ear bones. And you can plug that gene in and guess what happens? The offspring of the mouse will have a perfectly normal inner ear bone. So you can swap out all these files. I mentioning this to you because when you hear about we are 99% similar (to chimps) it is almost all referring to those protein coding regions. When you start looking, and you start comparing different mammals. Dolphins, aardvarks, elephants, manatees, humans, chimpanzees,, it doesn’t really matter. What you find is that the protein coding sequences are very well conserved, and there is also a lot of the DNA that is not protein coding that is also highly conserved. But when you look at the chromosomes and those banding patterns, those bar codes, (mentioned at the beginning of the talk), its akin to going into the grocery store. You see a bunch of black and white lines right? You’ve seen one bar code you’ve seen them all. But those bar codes are not the same.,, Here’s an example, aardvark and human chromosomes. They look very similar at the DNA level when you take small snippets of them. (Yet) When you look at how they are arranged in a linear pattern along the chromosome they turn out to be very distinct (from one another). So when you get to the folder and the super-folder and the higher order level, that’s when you find these striking differences. And here is another example. They are now sequencing the nuclear DNA of the Atlantic bottle-nose dolphin. And when they started initially sequencing the DNA, the first thing they realized is that basically the Dolphin genome is almost wholly identical to the human genome. That is, there are a few chromosome rearrangements here and there, you line the sequences up and they fit very well. Yet no one would argue, based on a statement like that, that bottle-nose dolphins are closely related to us. Our sister species if you will. No one would presume to do that. So you would have to layer in some other presumption. But here is the point. You will see these statements throughout the literature of how common things are.,,, (Parts lists are very similar, but how the parts are used is where you will find tremendous differences)
    http://www.discovery.org/multi.....-dna-pt-2/

    Dolphin DNA very close to human, – 2010
    Excerpt: They’re closer to us than cows, horses, or pigs, despite the fact that they live in the water.,,,
    “The extent of the genetic similarity came as a real surprise to us,” ,,,
    “Dolphins are marine mammals that swim in the ocean and it was astonishing to learn that we had more in common with the dolphin than with land mammals,” says geneticist Horst Hameister.,,,
    “We started looking at these and it became very obvious to us that every human chromosome had a corollary chromosome in the dolphin,” Busbee said. “We’ve found that the dolphin genome and the human genome basically are the same. It’s just that there’s a few chromosomal rearrangements that have changed the way the genetic material is put together.”
    http://www.reefrelieffounders......-to-human/

    Kangaroo genes close to humans – 2008
    Excerpt: Australia’s kangaroos are genetically similar to humans,,, “There are a few differences, we have a few more of this, a few less of that, but they are the same genes and a lot of them are in the same order,” ,,,”We thought they’d be completely scrambled, but they’re not. There is great chunks of the human genome which is sitting right there in the kangaroo genome,”
    http://www.reuters.com/article.....P020081118

    First Decoded Marsupial Genome Reveals “Junk DNA” Surprise – 2007
    Excerpt: In particular, the study highlights the genetic differences between marsupials such as opossums and kangaroos and placental mammals like humans, mice, and dogs. ,,,
    The researchers were surprised to find that placental and marsupial mammals have largely the same set of genes for making proteins. Instead, much of the difference lies in the controls that turn genes on and off.
    http://news.nationalgeographic.....m-dna.html

    Evolution by Splicing – Comparing gene transcripts from different species reveals surprising splicing diversity. – Ruth Williams – December 20, 2012
    Excerpt: A major question in vertebrate evolutionary biology is “how do physical and behavioral differences arise if we have a very similar set of genes to that of the mouse, chicken, or frog?”,,,
    A commonly discussed mechanism was variable levels of gene expression, but both Blencowe and Chris Burge,,, found that gene expression is relatively conserved among species.
    On the other hand, the papers show that most alternative splicing events differ widely between even closely related species. “The alternative splicing patterns are very different even between humans and chimpanzees,” said Blencowe.,,,
    http://www.the-scientist.com/?.....plicing%2F

    Widespread Expansion of Protein Interaction Capabilities by Alternative Splicing – 2016
    In Brief
    Alternatively spliced isoforms of proteins exhibit strikingly different interaction profiles and thus, in the context of global interactome networks, appear to behave as if encoded by distinct genes rather than as minor variants of each other.,,,
    Page 806 excerpt: As many as 100,000 distinct isoform transcripts could be produced from the 20,000 human protein-coding genes (Pan et al., 2008), collectively leading to perhaps over a million distinct polypeptides obtained by post-translational modification of products of all possible transcript isoforms (Smith and Kelleher, 2013).
    http://iakouchevalab.ucsd.edu/.....M_2016.pdf

    Multiple Overlapping Genetic Codes Profoundly Reduce the Probability of Beneficial Mutation George Montañez 1, Robert J. Marks II 2, Jorge Fernandez 3 and John C. Sanford 4 – published online May 2013
    Excerpt: In the last decade, we have discovered still another aspect of the multi- dimensional genome. We now know that DNA sequences are typically “ poly-functional” [38]. Trifanov previously had described at least 12 genetic codes that any given nucleotide can contribute to [39,40], and showed that a given base-pair can contribute to multiple overlapping codes simultaneously. The first evidence of overlapping protein-coding sequences in viruses caused quite a stir, but since then it has become recognized as typical. According to Kapronov et al., “it is not unusual that a single base-pair can be part of an intricate network of multiple isoforms of overlapping sense and antisense transcripts, the majority of which are unannotated” [41]. The ENCODE project [42] has confirmed that this phenomenon is ubiquitous in higher genomes, wherein a given DNA sequence routinely encodes multiple overlapping messages, meaning that a single nucleotide can contribute to two or more genetic codes. Most recently, Itzkovitz et al. analyzed protein coding regions of 700 species, and showed that virtually all forms of life have extensive overlapping information in their genomes [43].,,,
    Conclusions: Our analysis confirms mathematically what would seem intuitively obvious – multiple overlapping codes within the genome must radically change our expectations regarding the rate of beneficial mutations. As the number of overlapping codes increases, the rate of potential beneficial mutation decreases exponentially, quickly approaching zero. Therefore the new evidence for ubiquitous overlapping codes in higher genomes strongly indicates that beneficial mutations should be extremely rare. This evidence combined with increasing evidence that biological systems are highly optimized, and evidence that only relatively high-impact beneficial mutations can be effectively amplified by natural selection, lead us to conclude that mutations which are both selectable and unambiguously beneficial must be vanishingly rare. This conclusion raises serious questions. How might such vanishingly rare beneficial mutations ever be sufficient for genome building? How might genetic degeneration ever be averted, given the continuous accumulation of low impact deleterious mutations?
    http://www.worldscientific.com.....08728_0006

  4. 4
    aarceng says:

    Is that down from 2,000? That’s a minor adjustment, not an order of magnitude change.

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