This document discusses several of Charles Darwin's key concepts from The Origin of Species including natural selection, survival of the fittest, the peppered moth example, sexual selection, cross-pollination, hermaphrodites, flaws in Lamarckism and orthogenesis, and Darwin's metaphor of the tree of life. It covers Darwin's theory that nature selects traits for the benefit of the species while man selects for his own benefit, and how variations within species allow some individuals to outcompete others and pass on their traits.
20. “As buds give rise to growth to fresh buds, and these, if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications.” -Charles Darwin, The Origin of Species
Notas del editor
Natural selection is the process in which a species adapts to its environment… not by choice, but the individuals less suitable for their environment will die easier and not reproduce. The most suitable ones will reproduce and carry on their genes“Survival of the fittest” more like most likely to reproduce
Wrote Origin of species24 November 1859Idea of evolution was controversial but used evidence from research, correspondence, and experimentation.
Survival of the fittest" is a phrase which is commonly used in contexts other than intended by its first two proponents: British polymath philosopher Herbert Spencer (who coined the term) and Charles Darwin.Herbert Spencer first used the phrase – after reading Charles Darwin's On the Origin of Species – in his Principles of Biology (1864), in which he drew parallels between his own economic theories and Darwin's biological ones, writing, "This survival of the fittest, which I have here sought to express in mechanical terms, is that which Mr. Darwin has called 'natural selection', or the preservation of favoured races in the struggle for life."
Industrial revolution in england– lichens died, trees covered in soot
Prepotent pollen– pollen between species does not create hybrids because original pollen is “prepotent”
Male top female bottomMore deviation, more natural selection, more adaptationBees select flowersCross-pollinated flowers must be more desirable
Thalictrumdioicum (Early meadow-rue or Quicksilver-weed) is a species of herbaceous plants in the family Ranunculaceae. They are either male or female
“The switch from insect prey to pollen may have resulted from the consumption of prey insects which were flower visitors and were partially covered with pollen when they were fed to the wasp larvae.”Hive bees can suck out nectar from red clovers, which offers a large source of nectarIt is difficult for hive bees to suck out nectar from the Incarnate clover
Hermaphrodites?
Intraspecific competition is a particular form of competition in which members of the same species compete for the same resource in an ecosystem(e.g. food, light, nutrients, space). This can be contrasted with interspecific competition, in which different species compete.
Giraffe’s necks grew longer because they needed to… constantly stretching toward tall trees, passed down to offspringOffspring have slightly longer necks “soft inheritance”
epigenetics is the study of heritable changes in phenotype (appearance) or gene expression caused by mechanisms other than changes in the underlying DNA sequenceOur findings suggest that unpredictable food access caused seemingly adaptive responses in feeding behavior, which may have been transmitted to the offspring by means of epigenetic mechanisms, including regulation of immune genes. This may have prepared the offspring for coping with an unpredictable environment.... Transmissions of information across generations which does not involve traditional inheritance of DNA-sequence alleles is often referred to as soft inheritance [9] or 'Lamarckian inheritance'.[8]
Orthogenesis, orthogenetic evolution, progressive evolution or autogenesis, is the hypothesis that life has an innate tendency to move in an unilinear fashion due to some internal or external "driving force". The hypothesis is based on essentialism and cosmic teleology and proposes an intrinsic drive which slowly transforms species. George Gaylord Simpson (1953) in an attack on orthogenesis called this mechanism "the mysterious inner force".[1] Classic proponents of orthogenesis have rejected the theory of natural selection as the organising mechanism in evolution, and theories of speciation for a rectilinear model of guided evolution acting on discrete species with "essences". The term orthogenesis was popularised by Theodor Eimer, though many of the ideas are much older (Bateson 1909).[2]
In biology, saltation (from Latin, saltus, "leap") is a sudden change from one generation to the next, that is large, or very large, in comparison with the usual variation of an organism. The term is used for occasionally hypothesized, nongradual changes (especially single-step speciation) that are atypical of, or violate, standard concepts - gradualism - involved in neo-Darwinian evolution
Darwin does not address where life came fromOr how new species come aboutQuestions arose and led to lamarckismetc
Artificial selectionCarrotsMan influences the growth and change within species by planting more or less of a certain plant, breeding for specific traits
