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No Researcher Knows So Much About Iodine And Human Evolution As The Italian Dr Sebastiano Venturi

Discussion in 'Minerals' started by nigma, Sep 30, 2018.

  1. LeeLemonoil

    LeeLemonoil Member

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    https://www.researchgate.net/public...tion_by_Sebastiano_Venturi_and_Michel_E_Begin

    ntroduction Evolution of the hominin lineage is marked by progressive brain expansion and complexity concomitant with coordinated changes in other morphological and behavioral traits that characterize speciation events. In addition to gene variation, changes in climate, habitat, and diet are well-recognized environmental stimuli for evolutionary change. Iodine is an environmental stimulus to which living organisms react, a point particularly evident in amphibian metamorphosis and potentially also in hominin evolution. In toto, selection pressures effecting evolutionary change involve biological mechanisms permitting adaptation and evolution under changing environmental conditions. A common biological control mechanism could potentially coordinate a suite of physiological, morphological, and behavioral changes as important as brain evolution. We contend here that such a mechanism was hormonal and that thyroid hormone and iodine were pivotal components of such a mechanism. The principal fossil sites of hominins correlated in space and time with volcanic and fissural local or nearby iodine sources (Borensztejn, 2005). In vertebrates, iodine is incorporated into thyroid hormone in the thyroid gland. Crockford (2003, 2008) provided solid evidence that changing thyroid function, specifically rhythms of thyroid hormone secretion, is crucial for speciation events taking place over decades. The same thyroid hormone mechanism can be applied to the process of humanizing australopithecines. Here, we postulate a link between thyroid function, iodine, and evolutionary changes as they apply to the evolution of hominins and, more specifically, the large brain of Homo sapiens. We emphasize changes in habitat and the connection between enhanced dietary availability of iodine, selenium, and polyunsaturated fatty acids as brain-selective nutrients necessary for thyroid function and hominin brain expansion.

    https://www.researchgate.net/public...205_2014_Part_2_S_Venturi_M_Venturi_2014_LINK

    The structural, metabolic and synergic actions of iodine and polyunsaturated fatty acids (PUFAs) in life evolution and in the ‘membrane lipid language’ of cells are reviewed. Iodine is one of the most electron-rich atoms in the diet of marine and terrestrial organisms and, as iodide (I-), acts as an ancestral electron-donor through peroxidase enzymes. It is the most primitive inorganic antioxidant in all iodide-concentrating cells, from primitive marine algae to more recent vertebrates. About 500 million years ago, the thyroid cells originated from the primitive gut of vertebrates, then migrated and specialized in the uptake and storage of iodocompounds in the thyroid, a new follicular organ. In parallel, ectodermic cells, differentiated into neuronal cells, became the primitive nervous system and brain. Both these cells synthesized iodolipids, as novel ‘words’ of the chemical ‘lipid language’ devoloped among cell membranes during the evolution of life, for better adaptation to terrestrial environments. The study of iodolipids is a new area of investigation, which might be useful for research on apoptosis, carcinogenesis and degenerative diseases, as well as for trying to understand some problems discussed regarding human evolution.
     
  2. LeeLemonoil

    LeeLemonoil Member

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    Evolutionary roots of iodine and thyroid hormones in cell–cell signaling

    In vertebrates, thyroid hormones (THs, thyroxine, and triiodothyronine) are critical cell signaling molecules. THs regulate and coordinate physiology within and between cells, tissues, and whole organisms, in addition to controlling embryonic growth and development, via dose-dependent regulatory effects on essential genes. While invertebrates and plants do not have thyroid glands, many utilize THs for development, while others store iodine as TH derivatives or TH precursor molecules (iodotyrosines)—or produce similar hormones that act in analogous ways. Such common developmental roles for iodotyrosines across kingdoms suggest that a common endocrine signaling mechanism may account for coordinated evolutionary change in all multi-cellular organisms. Here, I expand my earlier hypothesis for the role of THs in vertebrate evolution by proposing a critical evolutionary role for iodine, the essential ingredient in all iodotyrosines and THs. Iodine is known to be crucial for life in many unicellular organisms (including evolutionarily ancient cyanobacteria), in part, because it acts as a powerful antioxidant. I propose that during the last 3–4 billion years, the ease with which various iodine species become volatile, react with simple organic compounds, and catalyze biochemical reactions explains why iodine became an essential constituent of life and the Earth's atmosphere—and a potential marker for the origins of life. From an initial role as membrane antioxidant and biochemical catalyst, spontaneous coupling of iodine with tyrosine appears to have created a versatile, highly reactive and mobile molecule, which over time became integrated into the machinery of energy production, gene function, and DNA replication in mitochondria. Iodotyrosines later coupled together to form THs, the ubiquitous cell-signaling molecules used by all vertebrates. Thus, due to their evolutionary history, THs, and their derivative and precursors molecules not only became essential for communicating within and between cells, tissues and organs, and for coordinating development and whole-body physiology in vertebrates, but they can also be shared between organisms from different kingdoms.
     
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