“Survival of the Fittest” and “The Struggle for Existence”
What is FIT in the famous Natural Selection idea of “survival of the fittest “ ? Has everybody heard that phrase ? What is the Darwinian struggle for existence “ ?
An Individual organism, An Animal Body, has an instinct for self-preservation inborn in its brain. This is said to be the first law of nature. This is an inborn, genetically based instinct to live as long as possible (preserve itself) before its inevitable end, as all animals are _mortal_, don’t live forever (though only humans know this ; other species do not ). Every Individual Some Body has a limited lifetime or _ontogeny_ in which it is born, develops, exists and dies. This development of an Individual overtime is not evolution , but _ontogeny_. Evolution is the change or development of a species or a geno-TYPE or GENOME over two or more generations. It is change in the body type of a population of animals , not just one animal as in ontogeny.
Physically fit , in the sense of individual bodily fitness, means fit to literally fight or flee or labor for success in the “ struggle for existence”, or the struggle to survive . HOWEVER , fitness of the individual is NOT the fitness of Darwinian “survival of the fittest”. What survives in “survival of the fittest” are genes passed on and surviving in the next generation, in the offspring, children, of parental generation.
“The struggle for existence” is the Darwinian term of art for longevity in an individual organism living : getting enough to eat , not getting eaten , not falling out of a tree or off a cliff , not freezing to death , not overheating to death, not drowning , not getting deathly ill BEFORE REPRODUCING , BEFORE BEING FERTILE, passing on one’s genes to next generations .
The latter, differential fertility, is more important in determining Darwinian fitness than differential mortality. In other words, success or failure in mating and producing fertile offspring is more important in determining a Body _Type’s_ fitness, a genotype’s fitness, than success in the struggle for existence, (the struggle for the individual animal to survive). Although, the longer an individual lives, the greater the likelihood it will successfully produce fertile offspring, so differential mortality (comparing two animals’ longevities) does impact differential fertility ( comparing two animals’ success in producing fertile offspring)
It is a genotype or a species that has fitness or unfitness, not an individual organism. Because an individual animal cannot survive forever and perpetuate the species; only its genotype can be perpetually passed on down through the generations.
So, Darwin’s principle of Natural Selection is actually survival of the _fertile_ , the fertile –TYPE; the fit types are more fertile than the unfit types . Fertility success is the Darwinian definition of fitness success.
In Darwin's theory, the "struggle" in the struggle for existence, to live, is NOT between Individual Selves of the same species to the point of Individual Bodies, somebodies, of the same species killing each other except very rarely. Most of the deaths before passing on genes to the next generation, are due to failures in struggles with some Individual Body of _another_ species, plant and animal, as predator and prey; or struggle against bad weather, heat exhaustion, sunburn.
It is easy to see how some people get a misconception of Darwinian natural selection because it _is_ posed in most of its prime formulations with a sort of emphasis on the fact of indirect "competition" in the sense that for the typical bodily form of a species to change over generations under Darwin's theory, some members with genes that change the species typical traits must more successfully pass them on than members with species typical traits over successive generations until the new trait is universal , and the old typical trait is extinct. But this does not necessarily or even conventionally imply direct physical conflict between Individuals of the two types but of the same species in the day-to-day struggle for existence to live, not die, as Individual Bodies.
This is demonstrated by the famous anthropological micro-evolutionary study of sickle cell genes on pages 95 to 98 of _Physical Anthropology_ (12th edition). There is no direct physical competition between the people of the various genotypes with different fitnesses in the different environments in the study. It is not an Individual , but a species over generations , a group of the same type who "evolve", "adapt" or "survive". Individuals must live their individual life long enough to reproduce for the species to survive. However, every individual eventually dies. "Survival" of the individual means living long enough to pass on genes or a geno-type to the future generations. If mutated genes, changed geno-type, are passed on, there is a potential unit of evolution between the parent and the offspring. That is evolution occurs between Individuals of different generations, not in one Individual Self. If the mutated genotype results in a phenol-typical trait that is adaptive in some significant way, it may become an evolutionary change by the species through several individuals of different generations.
Significantly, the institution of war which arises in human history with so-called civilization around 6,000 years ago involves human Individuals violating their natural instinct of self-preservation. Going into battle is to risk one's individual life for a social value of some type, nationalism or religion, not the exercise of a non-existent "instinct of aggression". Humans do not even eat those they kill in most war ( joke) , another unnatural aspect. No animal species kills without the motive of getting food.
))))))))))))))))))))))))) 1) Concerning the test, a)please put the word “discuss” in front of each question ; b) ask yourself as you answer the questions, “ why is the professor asking this question ? ‘; try to connect the answers with each other.
2) Write out three questions you have about the last two classes and the readings .
(15 minutes) 3) A student usually asks : “Can you explain the phylogenetic tree of life ?”
“Mammal”, “primate”, "hominin" , australopithecine , are taxonomic/phylogenetic / Tree of Life classifications. As we go down on the Tree of Life, there are increasingly inclusive categories or categories that include more and more species. So, australopithecines are hominins, but not all hominins are australopithecines ( for example ardipethicus is a hominin, but not an australopithecine). All hominins are primates, but not all primates are hominins; primates is a larger inclusive category than hominins, and includes all hominins. All primates are mammals but not all mammals are primates. All mammals are vertebrates , but not all vertebrates are mammals.
All hominins are primates, but not all primates are hominins. There are more primate species than hominin species, and the primate classification is further down on the Tree of Life than the hominin classification.
All primates are mammals, but not all mammals are primates. There are more mammal species than primate species ; and the mammal classification is lower on the Tree of Life than the primate classification.
Genus Homo, Homo habilis, Homo Erectus, Homo Neanderthal, Homo sapiens are taxonomic/phylogenetic classifications in Chapter 14 (not on Test 1)
Again , The logic of the Tree of Life: Increasing numbers of species included in the classifications as we go down on the Tree: So , all of the Genus Homo species are Hominins, but not all Hominin species are Genus Homo species. There are more Hominin species than Genus Homo species. Genus Australopithecine species and Genus Homo species are included in the classification Hominin. Only Genus Homo species are included in the Genus Homo. The Hominin classification is further down on the Tree than the Genus Homo classification.
_ What is the importance of the African location of “missing link” fossils as Darwin predicted ?_
The world of the last 500 years has been under the ideology of race based on skin color; more specifically an ideology of white skin supremacy and dark skin color inferiority ( I will discuss skin color variation more fully in the Chapter 17 on physical variation in the human species). For now, I am making the point that the Missing Link fossils and Early Human fossils being found exclusively in Africa basically contradicts the false ideology that light skinned humans are inherently superior to dark skinned humans. Therefore, it was important that Darwin, Raymond Dart , Robert Broom and the other anthropologists who discovered all the early fossils were White men. If it had been Black people discovering the fossils, they would not have been believed in major parts of white society. Evidence that parts of European society considered that the Missing Link species should have been found in Europe is the Piltdown FRAUD on page 250 of the text as an indication of the inherent superiority of Europeans.
“Missing Link” is using the “Links in a chain” metaphor to portray an evolutionary line of descent from the species that was the common ancestor of chimps and early hominins; from early hominins to late hominins or Genus Homo species. Australopethicus is a Darwinian MISSING LINK FOSSIL. It has a chimplike brain , but walked BIPEDALLY.The links are better portrayed graphically as follows:
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