Transcript Evolution:

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.
• •Prebiotic:
As evolution
progresses,
four of these stages have taken place:
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 Ideas
vs.
•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
Carl Linnaeus (1707-1778)
Eramus Darwin (1731-1802)
Jean Baptist Lamarck (1744-1829)
Thomas Malthus (1766-1834)
Georges Cuvier (1769-1832)
Charles Darwin (1809-1882)
Alfred Russel Wallace (1823-1913)
Gregor Mendel (1822-1884)
Ernst Haeckel (1834-1919)
Alfred Wegener (1880-1930)
Lynn Margulis *still living*
Linnaeus: Classification
•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.
•Though
changes
have
been made to
the system, it is
still is use today.
Kingdom
Phylum
Class
Order
Family
Source:http://www.ucmp.berkeley.edu/history/linnaeus.html
Genus
Species
Erasmus Darwin: The Naturalist
•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.
Source: http://www.ucmp.berkeley.edu/history/Edarwin.html
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.
•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
•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.
Source: “Malthus, Thomas Robert”, Microsoft Encarta
2003
Cuvier: Comparative Anatomy
•Georges Cuvier, (1769-1832), studied structural
features of species and confirmed extinction.
Source: http://www.ucmp.berkeley.edu/history/evothought.html
•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 homologous
structures.
Source: http://www.wvup.edu/ecrisp/g112lecorganicevolution.html
Charles Darwin: “The Origin of Species”
•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.
Source: http://honors.ccsu.ctstateu.edu/Honors/EText/Darwin/DarwinTimeLine.html
•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.
The H.M.S. Beagle
•He wrote a now-famous book on his theories entitled
“Origin of the Species”.
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”.
•Mendel establishes two important laws:
THE LAW OF SEGREGATION
•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.
Source: “Mendel, Gregor Johann”,
Microsoft Encarta 2003
THE LAW OF
INDEPENDENT
ASSORTMENT
•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.
•Thinks that the “history of the
embryo” is connected with the “history
of the race”.
•ONTOGENY
RECAPITULATES
PHYLOGENY
(The history of the embryo is
repeated in the history of the race
=> cycle).
Source: http://www.ucmp.berkeley.edu/history/haeckel.html
Wegener: Plate Tectonics
•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:
PANGEA
…which, since the formation of the Earth, has drifted apart with the
movement of the plates of the Earth’s crust.
•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.
Source:http://www.ucmp.berkeley.edu/history/wegener.html
Map of Pangea
Source: http://www.scotese.com/newpage8.htm
Margulis: Endosymbiotic Theory
•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
Source: http://biology.kenyon.edu/HHMI/Biol113/the%20endosymbiotic%20theory.htm
Endosymbiotic Theory: Visual
Source: http://www.biology.iupui.edu/biocourses/N100/2k2endosymb.html
Summary
•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:
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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
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
•
How would the continental drift theory account for
identical fossils found in Brazil and South Africa?
2. Describe the endosymbiotic theory, using diagrams and
suggesting evidence for this theory.
3. How plausible is tracing ancestry with comparative
anatomy? State your opinion with an explanation.
4. Why is evolution said to act on populations rather than
individuals?
Poem by Erasmus Darwin“Organic life beneath the shoreless waves
Was 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.
Bibliography
Benson, Keith R. “Microsoft Encarta: Jean-Baptist Lamarck” Funk & Wagnalls: Microsoft
Encarta, 2003.
Crisp, Edward L. “Organic Evolution”
http://www.wvup.edu/ecrisp/g112lecorganicevolution.html
Online [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.html
Online [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.html
Online [Available]
May 25, 2003
Bibliography (cont.)
Kahn, Paul et al. “Gregor Mendel: The Genius of Genetics”
http://www.mendel-museum.org/eng/1online/garden.htm
Online [Available]
May 30, 2003
King, Dr. Peter. “Human Biology”
http://www.fmarion.edu/~peterking/humanbio.html
Online [Available]
May 25, 2003
Lye, Bethany. “The Endosymbiotic Theory”
http://biology.kenyon.edu/HHMI/Biol113/the%20endosymbiotic%20theory.htm
Online [Available]
June 4, 2003
Soctese, Christopher R. “Palomar Project”
http://www.scotese.com/newpage8.htm
Online [Available]
June 8, 2003
Smith, Charles H. “The Alfred Russel Wallace Page”
http://www.wku.edu/~smithch/index1.htm
Online [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, Cercie
http://www.biology.iupui.edu/biocourses/N100/2k2endosymb.html
Online [Available]
June 4, 2003