EPIGENETICS AND THE EVOLUTION OF HUMAN BEINGS
The author of this blog is neither a geneticist nor an anthropologist, nonetheless, the intent herein is to point out that recent scientific discoveries in a subject known as epigenetics that may have a profound impact upon the evaluation of paleoanthropology relating to the evolution and the emergence of the homo sapiens.
Epigenetics is defined as the study of heritable changes in gene expression that “DO NOT” alter DNA sequences. The outside forces that cause changes in the gene expressions are not permanent mutations, nonetheless, these forces orchestrates how a DNA molecule unwinds its various sections to make proteins or even new cells. The continuing study of genetics over the past 60 years has shown the ultimate profundity and enigmatic complexities involved in these research studies. This paper will not address any of these aspects of those countless studies other than the possible mechanism of epigenetics. Example below from Wikipedia.
Epigenetic effects on on genes take place within the Chromatin DNA (gene)complex and the histone proteins (the little spheres) that the DNA are rapped around. If the amino acids that make up the histone protein spheres are in any way modified, the DNA will change its replication sequence. There are many known histones modifying agents. The results of these modifications can have profound affects on the templates that will produce different amino acids, proteins, cells and may ultimately affect the total organism, without any “GENE MUTATION”. There are also direct modification to the DNA by agents, such as methyl groups, that have the tendency to instruct those genes to be less active when they are transcribed into the RNA; also without genetic mutation. (1)
The vast amount of research in genetics over the past 50 years, in species such as bacteria, fungus, parasites, plants and animals, including human, has shown that EPIGENETICS is an evolutionary phenomenon common to all of these species. And, no doubt, a vital functional survival mechanism to all of those species.(2)
EPIGENETICS AND OUR EVOLVING SPECIES
The role of the genes in multicellular animals is to progress with their fantastic agendas starting with the fertilized oocyte to become the total normal organism dictated by their entire genetic potential. In human beings, ideally, normalcy in their offsprings would require healthy parents that were progenies of long lines of healthy antecedents. Further, the mother’s pregnancy should be ideal with her ingestion of all of the perfect nutrients for fetal development, and reframing from any behavior patterns that would in anyway interfere with her offsprings normal birth for the 9 months of her pregnancy. However, this scenario has not always been the case for our evolving human species. (3)
In the evolving scenario of our species the environmental totalities played an enormous role in our survival. Environmental factors would include climate, foods that would be available in their locals, predator avoidance, and the ability for pregnant females to have reasonable good gestation periods. (4)
CLIMATE: Radical climate changes could have detrimental effects
DIETS: Poor diets (including poor proteins, fats, carbohydrates, vitamins and minerals) and/or inadequate nutrition (referring to sparse amounts of available foods) has recently been shown in a myriad of animal studies not only to greatly affect the different subject animals, but also at the “least, several generations of their progeny”. These are considered epigenetic effects. (5)
IN UTERO DEVELOPMENT: Any disturbance therein could affect the fetus and its developmental future which would also be considered epigenetic, with no DNA mutations. (6)
EVOLUTION OF THE PLANET MASTERS, HOMO SAPIENS
This subject can be described as conjectural, argumentative and messy. There has always been widely divergent opinions relating to the interpretations of the variety of fossil finds in Africa dating from 2 to 2.5 million years ago up to 60 to 70 thousand years ago. The ultimate question that arises is how these relatively weak upright walking species survived being prey for a myriad of predators, and, to become the only human species on the planet at this time, Homo sapiens. (7)
Although the suggested facts have had a variety relatively close numerations, the common ancestor of chimpanzees and human divided between 5.5 million to 8 million years ago. Homo sapiens and chimpanzees share between 95 to 98 % (depending upon whom you believe) of our genes. Homo sapiens share 99 to 99.5 % our genome with Homo neanderthals. (8)
From the fossil evidence there had been more than several contemporary species that co-existed in Africa from those ancient dates of 2.5 million to 70 thousand years ago. During these continuing evolving years some species became extinct while other flourished. Nonetheless, between 60 and 70 thousand years ago,(possible 80 to 100 thousand years ago) some of the species that were considered to be Homo sapiens left Africa to populate the rest of the planet. The first group probably took a coastal route and eventually reach present day Australia about 50 thousand years ago. Another group ended up in present day Europe about 40 thousand years ago, possibly migrating west from Asia, and encountered their close relatives Homo Neanderthals, whom for reasons unknown became extinct by 28 thousand years ago. (9) Nonetheless, there is genetic evidence that between 1 to 4 % of europeans and near eastern asians carry Neanderthal DNA. Further complicating the genetic evidence the recent discovery of the Denisovans, whose DNA (4 to 6%) are found in Aborigines of Australia, in populations of New Guinea, and many Pacific Islanders. There was without question that these closely related species interbreed. (10)
WHAT IS THE BOTTOM LINE ABOUT THE HOMO SPECIES?
The science of anthropology is replete with enormous divergent opinions about the evolution of Homo sapiens. Those opinions are constantly also “ EVOLVING”. It seems that the science of genetics has greatly added to the overall confusion. And, the propensity to give different names to every new human-like fossil find also promotes argumentative points of view to the various school of anthropologist. However, there is probably much less diversity among the fossils than they are given credit for. They are all Homo. EPIGENETICS HAS SHOWN, UNEQUIVOCALLY, THAT EVOLUTION CAN BE ON A CONTINUING AND DIVERGENT PATH WITHOUT ANY CHANGE IN GENETICS. Those interbreeding species that did not quite look like one another from all over the planet may very well be the same species. To make this point clearer; what if in the far future in greatly separated locals fossil finds of humans that would have been, in their lifetimes: A 322 pound lineman from the Chicago Bears; A 52 pound Dwarf; A 67 pound woman who died from anorexia; A tremendously obese 502 pound man. A 7 foot center from the Los Angeles Lakers? Many schools of anthropology would give these fossils a different names!
DARWIN AND EPIGENETICS
Darwin’s “ survival of the fittest”, in modern reality is the survival of the species with the best EPIGENETICS.
EPIGENETICS; OUTSIDE IN; NOT INSIDE OUT
The original role of the genetic code within a fertilized egg, is to enigmatically, produce molecules, cells, organs and eventually the whole organism. Thereafter, its role dramatically changes. The genes of our human species become hidden away in each and every differentiated cell phenotype, in the nuclei of most protected area of each cell. The position of the genetic machinery within each and every differentiated cell is called “cellular polarity”. This is for genetic protection. It is the last place in the cell that has contact with its peripheral environment and the outside world. Therefore, any information, nutritional enhancement, challenging molecular toxins, arriving and going through the nuclear pore system in order to affect the genetic machinery within all cells passes from the “Outside In”.
CLOSELY RELATED SPECIES AND CONSCIOUSNESS
To reexamine the diverse fossil finds in Africa, that were contemporary in term of epigenetics, an argument can be made that those so named different species may have been intimately genetically related. Their differing structural anatomies may had come about from the diverse environmental factors now recognized by the research and further demonstrated by the science of EPIGENETICS.
There has been speculation that Homo sapiens survival skills were preceded by a previous genetic mutation that, at a later date manifested as symbolic thinking. (11) We take exception to this premise as this is a conjectural interpretation of a genetic mutation being in place long before the change in consciousness is needed. Even at this present time with the plethora of on going brain and neuronal research, the enigma what our consciousness is, and what is manifesting it remains unknown. Evolution has always gone from the more simple to the more complex. Our consciousness should have followed that same path without a mutational accidents in our genes.
Human consciousness that great mystical divider of homo sapiens and all other species extant on our present day planet, and, further divides each and every individualized human being has had an evolving past and will have an evolving future. Accidental mutations in our enigmatic DNA that portend an advantage to enhanced survival, (Darwinism) are not the way that evolution takes place. That premise would mean that every species living at this time on this planet came about through a mutational accident. Recent research in epigenetics shows that the adaptabilities of the DNA structures can set life forms into agendas that evolutionarily survive and flourish in our constantly changing world, without permanently changing the DNA structural complex. Therefore, epigenetic changes in the human DNA mechanisms can induce dramatic changes in amino acids proteins, cells, organs and perhaps most incredibly, the total human organism.
A recent published paper showed that two breeds of Mexican howler monkeys, mantled and black, that diverged 3 million years ago, interbreed when their inhabitable zones became intertwined. After many generations of interbreeding the resulting hybrids were impossible to physically distinguish from the pure breeds, although their genomes showed a great mixture of each species. (12)
Cro-magnons, neanderthals and denisovans were millions of years closer that those howler monkeys.
There is a possibility that many homo species that were deemed different species were more closely related than ever before believed. Their anatomical differences in their overall appearances could have been due to epigenetic mechanisms. The differently named specimens finds by the anthropologists were probably nothing more than the extremely diverse racial groups found in all of the geographic locations on planet earth today, all of whom are considered homo sapens.
- Epigenetics: From Wikipedia 8/8/2012.
- Transgenerational epigenetic inheritance: prevalence, mechanisms, and implications for the study of heredity and evolution. Jablonka E. and Raz G., Q Rev Boil 2009 Jun;84(2): 131-76
- Epigenetic Disruption: The Effect of Early Developmental Exposures. Autumn J Dermal and Randy L. Jirtle., Birth Defects RevA Clin mol Teratol, 2010 October: 88(10) 938-944.
- The role of nutrition on epigenetic modifications and their implications on health. Jimenez-Children JC. et al., Biochimie 2012 Jul 5 (Pub ahead of print)
- Timescales of genetic and epigenetic inheritance. Rando OJ and Verstrepen KJ., Cell 2007 Feb 23: 128(4) 655-68 Epigenome: the program for human health and disease. Randy L Jilt.
- Epigenomics (2009) 1(1) 13-16
- Fossil evidence for the origin of Homo sapiens. Schwartz JH ans Tattersall I., Am J Phys Anthropol 2010 ; 143 Suppl 51: 94-121
- Human origins out of Africa. Ian Tattersall.,PNAS september 22 2009 vol 106 #38: 16018-16021
- New fossils from Kobe in northern Kenya confirm taxonomic diversity in early Homo Leakey MG et a., Nature 20012 Aug 9;488(7410):201-4
- Denisovans, Neanthertals, Archaics as Himan Races. Anthropology 1.11 http://www. livinganthropologicallycom/anthropology/denisovans-neanderthal-human-races
- Human evolution and conition. Tattersall I., Theory Biosci 2010 Sep; 129(2-3): 193-201
- Morphological variation of genetically confirmed Aloutta PIRG xA. palliate hybrids from a natural hybrid zone in Tabasco, Mexico. Ciliate MA, Cortes-Ortez L. Am J Phys Anthopol. 2012 Dec 7. doi: 10.1002/ajpa. 22196