Evolution:

The History of Evolution

Overview• What is the history of evolution?

• Pre-scientific revolution ideas

• Influential scientists and their theories– Timeline– Scientists and theories

• Summary

• Reading

• Questions

• Poem by Erasmus Darwin

• Bibliography

What is the History of Evolution?• Evolution is the genetic change occurring in a population of organisms over many

generations. This may lead to a proliferation of different kinds of organisms as single groups of organisms give rise to 2 or more distinct kinds of descendents.

• In the long term, a change up to a new level is known as a metasystem transition.

• As evolution progresses, four of these stages have taken place:

•Prebiotic: formation of substance and the universe

•Biological: development of life on Earth

•Cognitive: evolution of nervous system and brain use

•Social: origin of interactions between organisms

Pre-Scientific Revolution Ideasvs.

•Church disputes many scientific theories, (e.g. Heliocentric universe) because they contradict the Bible.

•Many scientists are afraid of the power of the all-encompassing Church, making it hard for new ideas to be published and presented.

•In the seventeenth century, the Scientific Revolution takes place, and scientific theories gradually become accepted by the public.

•After the Scientific Revolution, many theories on evolution were developed, making progress on what had been previously stated by Aristotle and accepted for years.

Influential Scientists and their theories

Eramus Darwin (1731-1802)

Thomas Malthus (1766-1834)

Charles Darwin (1809-1882)

Gregor Mendel (1822-1884)

Ernst Haeckel (1834-1919)

Alfred Wegener (1880-1930)

Carl Linnaeus (1707-1778)

Jean Baptist Lamarck (1744-1829)

Georges Cuvier (1769-1832)

Alfred Russel Wallace (1823-1913)

Lynn Margulis *still living*

Linnaeus: Classification

KingdomKingdom

PhylumPhylum

ClassClass

OrderOrder

FamilyFamily

GenusGenus

SpeciesSpecies

•Carl Linnaeus, (1707-1778), known as the “Father of Taxonomy”, made significant contributions to the organization of biology.

•He played a role in the history of evolution by making a thorough classification system for the living things on the planet.

Source:http://www.ucmp.berkeley.edu/history/linnaeus.html

•Though changes have been made to the system, it is still is use today.

Erasmus Darwin: The Naturalist

Source: http://www.ucmp.berkeley.edu/history/Edarwin.html

•Lived from 1731-1802, perhaps most famous because he was the grandfather of Charles Darwin.

•Writes some of first theories on evolution that are published in “The Laws of Organic Life”; is also a poet.

•Like many scientists of that time, works on a wide variety of fields: geography, embryology, anatomy, integrating them to lead to theories on

evolution.

•Significant contribution: Through observation, comes up with the idea that species evolved from a “single common ancestor” and it notices that it seems that the strongest males were able to succeed in competition for mates and thus create offspring.

Lamarck: Inheritance of Acquired Characteristics

•Jean-Baptist Lamarck lived from 1744-1829.

•Though covered many fields, contributes as an “invertebrate zoologist”.

•Famous theorist: Main theory states that species change due to the environment that they are in, and this is passed down through generations.

•This theory is known as Lamarckism.Lamarckism.

•For example, thinks giraffes developed long necks because they had to stretch to reach higher branches.

•Now, this theory is believed to be incorrect, (accepted idea is that species evolve by genetic changes instead).

•Lamarck theorizing still contributed because he observed that species change and evolve over time, eventually adapting to suit their environment or otherwise dying out.

Malthus: Population Expansion

Source: “Malthus, Thomas Robert”, Microsoft Encarta 2003

•Thomas Malthus (1766-1834) was an economist, who contributed to the history of evolution with his studies on demography.

•Malthus thought that a population would be limited by the amount of food that was available to feed the population.

•Darwin used some of Malthus’ ideas in his own theories and book.

Cuvier: Comparative Anatomy

Source: http://www.wvup.edu/ecrisp/g112lecorganicevolution.html

Source: http://www.ucmp.berkeley.edu/history/evothought.html

•Georges Cuvier, (1769-1832), studied structural features of species and confirmed extinction.

•Cuvier looks at skeletal structures to see similarities or relationships between them.

•These relationships are traced back to find from where the species evolved.

•Similar structures that are thought to have descended from the same ancestor are known as homologoushomologous structures.

Charles Darwin: “The Origin of Species”

The H.M.S. Beagle

•Perhaps the most well-known figure in evolution, Charles Darwin lived from 1809-1882.

•Darwin came from a wealthy family, but had little schooling.

•His father sent him on a trip around the world in the H.M.S. Beagle, where he acted as a naturalist.

•On his trip, he visited the Galapagos Islands, and became interested in sub-species of finches that he found.

•From this stand-point, he theorized on evolution and came up with the theory of natural selection.

•He wrote a now-famous book on his theories entitled “Origin of the Species”.

Source: http://honors.ccsu.ctstateu.edu/Honors/EText/Darwin/DarwinTimeLine.html

Mendel: Genetics•Gregor Mendel, who lived from 1822-1884, is often known as the “Father of Genetics”.

•By studying pea plants he came up with the idea that offspring get a pair traits from their parent by inheriting half of the pair traits from each parent (Mendel called these “units”, but they are now known as “genes”.

Source: “Mendel, Gregor Johann”, Microsoft Encarta 2003•Mendel establishes two important laws:

THE LAW OF SEGREGATIONTHE LAW OF SEGREGATIONTHE LAW OF THE LAW OF

INDEPENDENT INDEPENDENT ASSORTMENTASSORTMENT

•Though genes are normally in pairs, during the formation of gametes, each pair goes into a separate sex cell.

•The two sex cells join in the offspring, combining the genes, and displaying the dominant gene.

•States that usually when one trait is shown, it is not affected by the appearance of other traits.

Wallace: Survival of the Fittest•Alfred Russel Wallace (1823-1913) is less well-known than Darwin, but they developed the same concepts, separately, at the time.

•Wallace, like Darwin, was a naturalist who traveled around the world collecting specimens, yet Wallace was less wealthy than Darwin.

•From research done in South America and Asia, he developed the idea of natural selection.

•Wallace wrote “The Malay Archipelago” and “Contributions to the Theory of Natural Selection”.

•Some say that Darwin’s theories have little proof, but together with Wallace, the idea of natural selection has proved sufficient enough to withstand as the modern accepted theory.

Haeckel: Ontogeny Recapitulates Phylogeny•Ernst Haeckel: (1834-1919) studies invertebrates and is inspired when he reads Darwin’s “Origin of the Species”.

•Disagrees slightly: Haeckel thinks environment acts on species, and so species can only survive if they can tolerate their environment.

Source: http://www.ucmp.berkeley.edu/history/haeckel.html

•Thinks that the “history of the embryo” is connected with the “history of the race”.

•ONTOGENY ONTOGENY RECAPITULATES RECAPITULATES PHYLOGENYPHYLOGENY

(The history of the embryo is repeated in the history of the race => cycle).

Wegener: Plate Tectonics

Source:http://www.ucmp.berkeley.edu/history/wegener.html

•Alfred Wegener, (1880-1930), had much interest in geophysics.

•When he heard about identical fossils found on opposite sides of an ocean, he began developing his theory that the land on Earth was originally united as a mass:

PANGEAPANGEA

•Wegener theorized that the continents could have fit together (ex. Africa and South America, see map on next slide).

•Fossils from different climates than where they were found gave further evidence of the theory.

•Land-bridge theory: creatures (humans included) could have traveled over connecting strips of land as the continents drifted apart.

…which, since the formation of the Earth, has drifted apart with the movement of the plates of the Earth’s crust.

Map of Pangea

Source: http://www.scotese.com/newpage8.htm

Margulis: Endosymbiotic Theory

Source: http://biology.kenyon.edu/HHMI/Biol113/the%20endosymbiotic%20theory.htm

•Lynn Margulis (still living) created a hypothesis for the evolution of eukaryotes.

•This currently-accepted theory was proposed in 1967.

•The endosymbiotic theory suggests that the organelles mitochondria and chloroplasts found in present-day eukaryotes were once prokaryotic organisms that developed a symbiotic relationship with larger organisms.

the larger organism provides protection from external environments, while the mitochondria offers energy (ATP), and the chloroplasts are able to photosynthesize.

Some Suggested Evidence:

-mitochondria & chloroplasts contain DNA

-both organelles also contain ribosomes

Endosymbiotic Theory: Visual

Source: http://www.biology.iupui.edu/biocourses/N100/2k2endosymb.html

Summary

• Carl Linnaeus: classification of organisms

• Erasmus Darwin: idea of a single common ancestor

• Jean-Baptist Lamarck: species inherit characteristics, changing with time

• Thomas Malthus: population expansion has restrictions (ex. Food shortage)

• Georges Cuvier: trace ancestry by comparing anatomy

• Charles Darwin: theory of natural selection

• Gregor Mendel: laws and understanding of genetics

• Alfred Wallace: theory of “survival of the fittest”

• Ernst Haeckel: “Ontogeny recapitulates phylogeny”

• Alfred Wegener: Continental drift theory

• Lynn Margulis: Endosymbiotic theory

•In summary, in the last three centuries, the concept of evolution has been developed and reviewed many times over, creating the history of evolution.

•Significant theorists and theories covered in this presentation include:

Clearly, evolution will have occurred because of the change ion allele frequency (i.e. the proportion of a particular allele in a given population.)

As a consequence, the gene pool of a population will have changed because of the selective pressure imposed by the environment.

Such pressures/forces that are normally encountered by living organisms in their quest for survival is referred to as NATURAL SELECTION.

Natural selection does not cause genetic changes in individuals but in populations. Evolution is considered to occur in populations rather than individuals.

Suggested Readings

• University textbook- “Life: The Science of Biology”, available

online at www.thelifewire.com

•Part 3 is all about evolution, and provides further detail on continental drift, Mendelian genetics and more, with online animated tutorials, self-quizzes, and more suggested readings.

•Sara Stein’s “The Book of Evolution”.

•Excellent in-depth explanation of evolution, summarizing modern theories on evolution.

Questions

2. How would the continental drift theory account for identical fossils found in Brazil and South Africa?

3. Describe the endosymbiotic theory, using diagrams and suggesting evidence for this theory.

4. How plausible is tracing ancestry with comparative anatomy? State your opinion with an explanation.

5. Why is evolution said to act on populations rather than individuals?

Poem by Erasmus Darwin-

“Organic life beneath the shoreless wavesWas born and nurs'd in ocean's pearly caves;First forms minute, unseen by spheric glass,Move on the mud, or pierce the watery mass;These, as successive generations bloom,New powers acquire and larger limbs assume;Whence countless groups of vegetation spring,And breathing realms of fin and feet and wing.”

-Erasmus Darwin. The Temple of Nature. 1802.

BibliographyBenson, Keith R. “Microsoft Encarta: Jean-Baptist Lamarck” Funk & Wagnalls: Microsoft Encarta, 2003.

Crisp, Edward L. “Organic Evolution”http://www.wvup.edu/ecrisp/g112lecorganicevolution.htmlOnline [Available]May 30, 2003

DeKosky, Robert K. “The Scientific Revolution, c. 1650” Events that Changed the World in the Seventeenth Century. Ed. Frank W. Thackeray, and John E. Findling. United States of America: The Greenwood Press, 1999.

“Endosymbiotic Theory”http://www.mrs.umn.edu/~goochv/CellBio/lectures/endo/endo.htmlOnline [Available]June 4, 2003

Genius Series: Charles Darwin (video) Producer: unknown, date unavailable

Heylighen, F. et. al. “The History of Evolution”http://pespmc1.vub.ac.be/HISTEVOL.html Online [Available]May 25, 2003

Irvin, C. Warren “The Charles Darwin Collection”http://www.sc.edu/library/spcoll/nathist/darwin/darwin.htmlOnline [Available]May 25, 2003

Bibliography (cont.)Kahn, Paul et al. “Gregor Mendel: The Genius of Genetics”http://www.mendel-museum.org/eng/1online/garden.htmOnline [Available]May 30, 2003

King, Dr. Peter. “Human Biology”http://www.fmarion.edu/~peterking/humanbio.htmlOnline [Available]May 25, 2003

Lye, Bethany. “The Endosymbiotic Theory”http://biology.kenyon.edu/HHMI/Biol113/the%20endosymbiotic%20theory.htmOnline [Available]June 4, 2003

Soctese, Christopher R. “Palomar Project” http://www.scotese.com/newpage8.htmOnline [Available]June 8, 2003

Smith, Charles H. “The Alfred Russel Wallace Page”http://www.wku.edu/~smithch/index1.htmOnline [Available]May 15, 2003

Bibliography (cont.)

Smith, David et al. “UCMP: Evolution Pages”http://www.ucmp.berkeley.edu/history.html Online [Available]May 15, 2003

Starr, Cerciehttp://www.biology.iupui.edu/biocourses/N100/2k2endosymb.htmlOnline [Available]June 4, 2003