Theory The Actuality of Darwinism

As Darwin by the middle of the 19th century enounced the fundamental ideas about how life evolves, latest genomics finds have come to strengthen and deepen his sights. Darwin main idea is that environment forces life to adapt and change. He found that idea when studying birds in the Galapagos Islands, East of the Pacific Ocean. As belonging to a same species, some had a strong, nut-cracking beak or others lean, elongated ones. He eventually found that that was due to environmental pressure. Strong-beaked birds were living on one island where they mostly found hard nuts to eat, as those with lean beaks were mostly dealing with a island providing for flowers and pollens. Environmental pressure, according to Darwin is making a difference between individuals in a species. The difference between those able to adapt to environmental change and those unable. The adaptable individuals further have the capacity to transmit their adaptation to their descendants. That makes the basis for the second main Darwin principle: the strong only are surviving in regard to environmental pressure as they are able to mate and transmit their adaptability. Which, more generally, is allowing for the species of those to survive and last as a species

Life science, since by the middle of the 20th century, have now made giant strifes with the science of genome, that programming code at the basis of any living being on Earth. Genomics data are coming to complement and precise Darwin ideas. The genome is the sequence of chromosomes which is defining one living being, and hereditarily transmitted to heirs. Each gene of the genome is coding for the development, or characteristics of a organ or a mechanism. 2 percent of genes only of the genome however are coding genes, those acting and effective through the creation of proteines. The remaining 98 percent are considered non-coding, 'dust bin-genes.' A main discovery of genomics lies about that 98 percent. Scientists found that any coding gene is sided with a so-called 'switch'. A switch is a small piece of DNA, which activates or inhibates the action of a coding gene. Such a switch associated with the gene coding for dark spots on a fly wings, for example, will be activating or inhibating the dark spots coding gene. Such switches, as far as they are concerned, are themselves triggered through so-called 'homeotic genes' which are no less than the A, T, C, G protein letters scaffolding the DNA. The main consequence in terms of darwinism of such a basic find, is that Darwin's view that all life may be described by a 'life tree', originating at a common trunk, is true as every species today may be traced back to common ancestors which in turn may be linked to distantcommon life forms! Scientists, for example, recently found that birds were parents to dinosaurs or humans to chimps. Any quadruped nowadays originate back to 360 million years ago when marine vertebrates -more simply fishes- turned into terrestrial ones. At that time, some fish species had his fins transformed into fore and aft legs, initiating a long line which survived until the mammals of today. Those fishes likely evolved that way to escape sea predators. Fins turning limbs simply allowed them to reach low level sea surfaces, and then ground, out of reach of predating species. The most amazing further is that there is a genomic explanation to that. Basic, most important genes are just trans-species and sided by same switches. Evolution is just how such or such gene is triggered by one's switch! Darwin thus was right. All living beings today can be traced back to the origins of life tree because a wholesale of basic genes always have been present since the early origin, in each different species all along that evolutionary tree. As far as fish fins turning limbs is concerned, for example, the switch either is not triggering the gene allowing for a limb and one gets a fin, or it triggers it and one has a limb! The gene then works limb bones out of the basic fin ones

A side effect of such findings is that man is not that different and has not a more specific place in the life tree than most of other living beings. Which is a other Darwin's idea, finally. When geneticians completely deciphered the human genome by the 1990s, they astonishingly found that the human genome was composed of 23,000 genes only, as estimations had forecast some 120,000 instead! With 23,000 genes, man's genome is no larger that the one of a chicken, and lesser than the one of maize, for example. A comparison further between chimps and man genomes brought, on the other hand, to that we have 99 percent of our DNA similar to those. Remaining, different one percent has been found related to the formation of our brain. The difference between us and chimps are lying too in switch-triggered genes, the half of them is in relation with brain making! Activation of such few genes, like a one linked to formation of the superficial layer of our brain or cortex is enough to making a massive difference to our ape parents. A current thinking is too that human beings progressively became more clever due to two gene-switch processes. A one allows for hand and toe thumbs. We are thus endowed with that powerful tool formed of thumb in opposition to other fingers. A other is linked to jaws. A switch in humans is triggering a less powerful jaw muscle to jaws. Apes jaws, at the contrary are as strong as a human quadriceps, that muscle in a man's upper leg. That thus is affecting the brain skeletal region. As brain bone plates are loose at birth and eventually solidify between themselves to definitively form the brain shell as a individual grows, the fact that apes jaw muscle is so powerful makes the traction upon bone plates strong enough to have those solidified early. With a weaker jaw muscle, humans bone plates solidify later -up to a age of about 30 years in a man of today. That delay makes bone plates keeping sufficiently loose to allow for a larger, and longer, development capacity, which likely is the explanation why successive human species had a larger brain than the previous

Recent research buoyed the idea that minute organisms, under one millimeter in size, might endured a different darwinism than larger ones. Among large organisms, chance would determine genetic changes as the number of steps of the development of one individual makes that environment validate, or not, that change. As far as minute organisms are concerned, chance remains the main factor but, as the steps of development are swift -like in a thrieving set of micro-organisms- environment ceases to be one. That would bring to that aleatory mutations in such populations are lasting and bringing a large variety of forms -and rendering the concept of species unefficient