Final Exam: Evolution and Ecology Flashcards
Great Chain of Being
aka scala naturae; an idea of a universal hiercharchy
metaphysical concept with gods tiered at the top, humans in the middle, and animals underneath
Nicholas Steno
- studied genealogy from theological point of view
- Provided insight into fossil record: “tongue stones” were sharks teeth, realizes that it must’ve represented something that lived and died
- Law of Superposition: lower levels of stratification are older than upper layers
Age of Discovery
Age of the Earth: Ussher
Age of Discovery happened in 15-17th century.
Age of the Earth: Ussher used Bible to say that Oct 6, 4004 BC, 9:00AM was the start of the Earth.
Darwin thought that the age of the Earth that people thought at the time was too young; ppl thought it was 6000 years old
Natural Theology
- Carl Linneaus
school of thought to prove the existence of God and divine purpose through observation of nature and the use of human reason; not dependent on revelations
Carl Linnaeus: created system of binomial nomenclature in Latin; transcended scientific category for all languages → now called taxonomy: inventory of life
Argument from Design
William Paley: organisms exist and function well therefore they were created by a being of high intelligence
Watch example: if you go outside and find a watch, you would think that someone had made it because it functions well; same with organisms
Adaptation vs Gradualism
ADAPTATION: form fits function
Bird beak example: osprey, tern, yellowlegs, loon, gull, night-heron, etc.
GRADUALISM: James Hutton; earth changes slowly but incrementally, thereby creating large changes with time
e.g. Grand Canyon
Extinction
Georges Cuvier: realized that some species die off without branching out to other forms of life
Jean Lamarck – Lamarckism (2)
no longer true
Principle of use and disuse: parts of an organism’s body that are used become more developed; parts that are not used become smaller and may disappear
Inheritance of acquired characteristics (mechanism of evolution): Changes achieved over an organism’s lifetime are passed on to its offspring
Uniformitarianism
Charles Lyell: says that we can’t assume anything that we can’t see, therefore he pushed for concrete evidence to prove theories; follows Hutton’s gradualism
Current laws of nature is the same as laws of nature in the past → Pushing theological ideas out of evolutionary biology (no miracles)
Alexander von Humboldt
Climbed Chimborazo volcano (S. Am) and recorded plants, discovered biological changes in altitude → origins of modern ecology / biogeography thru looking at the distribution of plants and animals across geographic zones / climates
Charles Darwin – HMS Beagle
five year contract; discovered many things; read Lyell and Humboldt; collected fossils and specimens through hunting expeditions; saw world in comparison framework
Charles Darwin – Law of Succession of Types
finding that living species generally resembled fossil forms of species from their same location
Charles Darwin – Galapagos Islands
endemic fauna; volcanically created chain of islands that was a good distance from South American coastline, preventing most species from traversing the coast; created an insular habitat and exclusive species with differences in form and behavior
Charles Darwin – Subsidence of Land Hypothesis
refers to the creation of coral atolls (eg. Mo’ orea in the Southern Pacific)
coral grows upward and outwards as the inner island disappears → Volcanic island - fringing reef - barrier reef - coral atoll
Morphological convergence
observed similarities across species in similar but distant environments
e.g. sugar glider and flying squirrel
Alfred Russel Wallace
unsung hero who collected specimen in the Amazon and worked with Darwin that came up with same ideas but in a different area; working class naturalist who published The Geographical Distribution of Animals
Charles Darwin – Pattern of Evolution
continuous, slow, gradual; change by “insensible degrees”
E. g. Darwinian giraffes: natural selection favors longer neck (better chance to get higher
Fecundity
large amount of offspring but only a few survive → AKA surplus production of offspring
e.g. pomegranate seeds, fish eggs
Individual Variation vs. Inheritance
INDIVIDUAL VARIATION: Genetic differences that are usually heritable; lead them to survive better in the wild (natural selection) or be chosen for animal husbandry (artificial selection)
INHERITANCE: Preservation of favored traits thru process of genetic transmission of characteristics from parent or ancestor to offspring
leads to differential survival / reproduction with successful traits as heritable and preserved due to the characteristics of nature → “Struggles for existence”
Explanatory power (6) A > C > H > V > E > F
used to support the pattern of evolution as proposed by Darwin
- Analogy: similarity of function and superficial resemblance of structures that have different origins e.g. wings in different organisms
- Convergence: organisms not closely related (not monophyletic), independently evolve similar traits as a result of having to adapt to similar environments or ecological niches
- Homology: shared descent from a common ancestor
Same organ in diff. Creatures
Ex: tail in whale and human - Vestigial structures: rudimentary organs
- Embryology
- Fossil record
“Difficulties on theory”
Missing links: fossil record does not show a continuous stream of evolution; there are chunks of species missing
That’s because organisms are very hard to preserve, we have a poor geological record that does not capture changes by insensible degrees; other factors: erosion, haven’t found them yet
Includes Ussher, organs of extreme perfection, and blending inheritance
Organs of extreme perfection
Evolution of eyes: critics asked how does a highly functioning organ come to be thru evolution → Darwin argues that the final form came about thru minor steps that have been perfected bc whole parts are developed in useful and gradual stages
The eye example: Shows convergence between the endpoints of the vertebrates (bird and human) and cephalopods (squid)
Blending inheritance
Offsprings uniformly blend the features of the parents
Eg. two extremes have offsprings who have offsprings… until offsprings “wash out” with no genetic variation
Gregor Mendel
Particulate inheritance: pea plants are bi-allelic (only 2 alleles are observable / important)
Used findings towards the genetic foundation of evolution