Scrap Notes #1: Evolution Study

My Thoughts On: November 17th, 2003

This is part of my archiving of my scrap notes. I don't like these files cluttering my hard drive, and hell, they make informative reads. So why not shove it into my website's database? Puts content on the site and helps my clutter. This contribution was a part of a basic study I did on Evolution a few years ago (when I was a more organized kinda guy), basically, just notes I took.

Evolution Scrap Notes:


Jean-Baptiste-Pierre-Antoine de Monet Chevalier de Lamarck (Jean-Baptiste Lamarck), 1744-1829

Notes: Created Lamarckism. Stated that creatures developed progressively, culminating in man. Proposed that creatures gained traits through acquired characteristics - this was later disproved.

Erasmus Darwin, 1731-1802

Notes: Charles Darwin's grandfather. Hinted on Evolutionary processes in his novel "Zoonomia, or the Laws of Organic Life"

Charles Darwin, 1809-1882

Notes: Theorized Evolution, proposed a method, Natural Selection, which directs Evolutionary development in a natural environment. Considered the founder of Evolutionary Biology. Published "Origin of Species by means of Natural Selection or The Preservation of Favoured Races in the Struggle for Life" in 1859 which summarized his theory, at the notice that Alfred Russel Wallace was developing a similar theory. Other novels followed, "The Variation of Animals and Plants Under Domestication" (1868), "The Descent of Man and Selection in Relation to Sex" (1871), "The Expression of the Emotions in Man and Animals" (1872). His theories of pangenesis and natural selection where proven to be wrong/inadequate after the study of molecular/cell biology arose.

Thomas Henry Huxley, 1825-1895

Notes: Often referred to as "Darwin's Bulldog", Huxley was a major public defender of Evolutionary Theory. He is also known for coining the term "agnosticism", and brought up the concept of "Social Darwinism".

Alfred Russel Wallace, 1823-1913

Notes: Wallace concieved and published works similar to Darwinian method before Darwin. He did so through independent methods. Wallace and Darwin publically shared the credit for Evolutionary theory during their times, despite Darwin being considered the founder.

Herbert Spencer, 1820-1930

Notes: Spencer was a contemporary of Darwin that went to further develop Evolutionary theory. Spencer is also known for popularly misusing the concept of Evolution in exaggerated sense of "Social Darwinism", borrowed from Huxley, and popularized the concept.

Gregor Mendel, 1822-1884

Notes: Mendel studied botany and developed a mathmatical model for genetics. Mendel's work primarily went undiscovered, but after his death Mendel's finding spawned a whole new concept inheritence, which came to rival Darwin's models.

August Weismann, 1834-1914

Notes: Weismann developed the science of genetics by theorizing a "germ-plasm" (later revised to a model of DNA structures) which organized each cell's function. Weismann's concepts revised the nature of Natural Selection, and later became termed "Neo-Darwinism".

Hugo DeVries, 1848-1935

Notes: Dutch botanist who rediscovered Mendel's works and popularized them. DeVries created a theory of mutation as means of Evolutionary change, indicating that heredity played a more important role in Evolution than Natural Selection. This model, termed Mutationism, contended with other naturalistic theories of Evolution.

Karl Pearson, 1857-1936

Notes: Founder of modern statistics, created a naturalist division in modern biology referred to as biometrics. Opposed Mutationism models of Evolution, thought Mendian models of heredity did not affect Natural Selection.

Ronald Aymer Fisher, 1890-1962

Notes: Statistician and geneticist, R.A. Fisher helped develop and find the Synthetic Theory of Evolution, which combined Mutationism and Neo-Darwinism into a new Evolutionary practice. He more widely known for adjustments to the scientific method in new models of experimentation such as randomization and variance, which employed different subsets and sampling methods in experimentation that makes the results more reliable.

John Burdon Sanderson Haldane, 1892-1964

Notes: Statistician and biometrician, J.B.S. Haldane helped develop the Synthetic Theory of Evolution, which combined Mutationism and Neo-Darwinism into a new Evolutionary practice. He was known in life for his contributions to enzyme research and his wide-ranging field of knowledge.

Sewall Wright, 1889-1988

Notes: American geneticist who helped develop the Synthetic Theory of Evolution, which combined Mutationism and Neo-Darwinism into a new Evolutionary practice. Wright helped find the study of population genetics, and the method of Genetic Drift, which became a part of the Synthetic Theory of Evolution. He also offered insight on the biology of inbreeding.

Theodosius Dobzhansky, 1900-1975

Notes: Published "Genetics and the Origins of Species", a novel with genetic findings that altered the landscape of Evolutionary Biology. Dobzhansky also finalized the concept of the Synthetic Theory of Evolution.

Ernst Mayr, 1904-unknown

Notes: Established concepts of speciation and contributed to the fields of avian taxonomy and population genetics. Contributed to the growth of the Synthetic Theory of Evolution.

Sir Julian Huxley, 1887-1975

Notes: Granson of Thomas Huxley, he contributed to hormone research and the study of behavior and Evolution. Contributed to the growth of the Synthetic Theory of Evolution.

George Gaylord Simpson, 1902-1982

Notes: Paleontologist who analyzed the intercontinental migrations of animals over time with changing geographical land masses. Contributed to the growth of the Synthetic Theory of Evolution.

George Ledyard Stebbins, 1906-2000

Notes: Called the father of Evolutionary Botany, Stebbins applied the Synthetic Theory of Evolution to plants, demonstrating Recombination and other methods. Contributed to the growth of the Synthetic Theory of Evolution.

James Watson, 1928-present

Notes: Contributed majorly to the deduction of deoxyribonucleic acids (DNA). Helped devise the double-helix and developed the model of genes. Also known for extensive virus research. Won a Nobel Prize for Physiology in 1962 with Francis Crick and Maurice Wilkins.

Francis Crick, 1916-present

Notes: Contributed majorly to the deduction of deoxyribonucleic acids (DNA). Helped create models of replication which lead to studies regarding the chemical processes behind DNA's function. Won a Nobel Prize for Physiology in 1962 with James Watson and Maurice Wilkins.

Maurice Wilkins, 1916-present

Notes: Contributed majorly to the deduction of deoxyribonucleic acids (DNA). Used X-Ray diffraction to help study the structure of small bodies. Later used X-Ray diffraction techniques for study of ribonucleic acids (RNA, related to viruses primarily). Won a Nobel Prize for Physiology in 1962 with James Watson and Francis Crick.

Motoo Kimura, unknown

Notes: Proposed the Neutrality Theory of Evolution, important molecular biology contribution to modern Evolution. The Neutrality Theory of Evolution states that most genetic changes are not prominent in a cell's function.

Steven Jay Gould, 1941-present

Notes: American paleontologist, science writer and Evolutionary Biologist. Proposed the theory of Punctuated Equilibria with Niles Eldredge, revising Darwinistic theory by stating that Evolutionary change occurs in quicker bursts with long periods of dormancy, as opposed to constient steady changes over time. Helped popularize modern Evolutionary Biology.


Progression to Modern Evolution

1. Lamarckism (Jean-Baptiste Lamarck, late 1700's/early 1800's)

2. Darwinism (Charles Darwin, 1859)

3. Neo-Darwinism (August Weismann, 1896)

4. Mutationism (Hugo DeVries, 1900)

5. Synthetic Theory of Evolution (Theodosius Dobzhansky, 1940-50's)

6. Molecular Biology/Modern Genetics (James Watson, Francis Crick, Maurice Wilkins, 1950)

7. Neutrality Theory of Molecular Evolution (Motoo Kimura, 1960's)

8. Biogeography

Note: Evolutionary study of plant and animal distribution/populations.

9. Evolutionary Ecology

Note: Evolutionary study of interactions taken between organisms and their environment.

10. Evolutoinary Ethology

Note: Evolutionary study of animal behaviour.

11. Sociobiology

Note: Evolutionary study of social behaviour, often considered the most controversial subfield of Evolutionary Biology.

12. Theory of Punctuated Equilibria (Steven Jay Gould, Niles Eldredge, 1972)

Evolutionary History:

Era: Precambrian

Time: 700-550 Million Years Ago

Period: Ediacaran (700-550m)

Events: First animal traces, first soft-bodied metazoans, first skeletal elements.

Era: Paleozoic

Time: 550-250 Million Years Ago

Period: Cambrian (550-500m)

Events: First fishes, first chordates.

Period: Ordovician (500-425m)

Events: Sudden diversification of metazoan families.

Period: Silurian (425-400m)

Events: First vascular land plants.

Period: Devonian (400-350m)

Events: First amphibians, jawed fishes diversify.

Period: Carboniferous-Mississippian (350-310m)

Events: Scale trees, seed ferns.

Period: Carboniferous-Pennsylvanian (310-290m)

Events: First reptiles.

Period: Permian (290-250m)

Events: Mass extinctions, reptiles diversify.

Era: Mesozoic

Time: 250-60 Million Years Ago

Period: Triassic (250-200m)

Events: First mammals, first dinosaurs.

Period: Jurassic (200-125m)

Events: Dinosaurs diversify, first birds.

Period: Cretaceous (125-60m)

Events: Extinction of dinosaurs, first primates, first flowering plants.

Era: Cenozoic

Time: 60 Million Years Ago to the present

Period: Tertiary (60m to under 1m)

Events: Mammals diversify.

Period: Quaternary (Under 1m to present)

Events: Evolution of humans.

Evidence for Evolution:

Evolution the Horse


54-38 Million Years Ago - Eocene Epoch

38-26 Million Years Ago - Oligocene Epoch

26-7 Million Years Ago - Miocene Epoch

7-2.5 Million Years Ago - Pliocene Epoch

2.5 Million Years Ago to 10,000 Years Ago - Pleistocene Epoch


1. Dawn Horse (Hyracotherium or Eohippus), (early Eocene Epoch)

Notes: Found in North America and Europe. Stood 4.2 to 5 hands high (dog-sized), arched back, raised hindquarters. Padded feet with four functional hooves on the forefeet and three on the hindfeet. Smaller, harder, muzzle and skull, smaller brain. Clearly distinct and larger molars, 4 premolars, 3 molars. Not originally suspected to be horse ancestor until later variations where found.

2. Orohippus, (late Eocene Epoch)

Notes: Similar in stature to Eohippus, but the 4th premolar had become molar-like. This signifies changes in diet.

3. Epihippus, (late Eocene Epoch)

Notes: Similar in stature to Eohippus and Orohippus, but the 3rd and 4th premolars had become molar-like. These changes where retained by all successions of horse.

4. Mesohippus, (early Oligocene Epoch)

Notes: Larger, averaging about six hands high, snout was more muzzlelike, legs where longer and more slender. Larger brain. Forefeet and hindfeet carried three functional toes and a foot pad. The teeth remained distinct to the Epihippus and Orohippus lineage

5. Miohippus, (late Oligocene Epoch early Miocene Epoch)

Notes: Larger than Mesohippus. Descendants split into multiple variations during the early Miocene Epoch.

7. Parahippus (early Miocene)

Notes: Had teeth adapted for eating grass, larger crests on the tooth and mouths made for side-to-side grinding. Teeth where developed so that a long crown was buried under the gum line, consitently being exposed so there is adequate grinding surface for the animal's life.

8. Merychippus (mid-late Miocene)

Notes: Fairly large (10 hands high), skull similar to that of a modern pony. Long bones in the lower leg became fused, for swifter running (preserved in all later variations of horse). Large central toe bore the central weight, foot pad was smaller/gone, two side toes became smaller. Strong ligaments joined the central toe to the leg. Hipparion, Neohipparian, Nannippus where all three toed descendants of Merychippus that continued, but did not lead to the modern horse.

9. Pliohippus (early-mid Pliocene Epoch)

Notes: Ancestor of the modern horse, direct lineage from Merychippus, noteably had one toe.

10. Equus (late Pliocene Epoch-early Pleistocene Epoch)

Notes: Genus to which all modern horses belong to - horses, asses, zebras - evolved from Pliohippus and had one toe. Straighter, longer cheek teeth, tighter more springy ligaments in the feet. Travelled more, extremely successful, in many major parts of the Old World and both North and South Americas. Equus disappeared from the North and South Americas between 10,000-8,000 years ago, this is attributed to the arrival of new diseases or the migration of human populations into the area who presumably hunted the horses for food, although this is still uncertain. Three modern members of the Equus genus - Przewalski's horse from Central Asia, Tarpan from Eastern Europe and Ukraine, and the forest horse of northern Europe - are all ancestors of the modern domesticated breeds.