Unit 1: The History of Evolutionary Thought Flashcards
What is Evolution?
a change in allele frequencies of a population across generations
What is an allele?
variant form in a genetic locus
What population?
potentially interbreeding organisms of the same species living in the same place
What is generations?
not within a lifetime of an organism
What processes cause evolution?
- natural selection
- genetic drift
- migration
- mutation
Microevolution -> Macroevolution
?
Who were the 2 major philosophers for the Ancient Greek regarding evolution?
Plato & Aristotle
What did the Ancient Greeks believe regarding Evolution?
- Organism are unchanging and represent perfect “types”
- Species were independently created and are fixed types
- Hierarchy (ex: apex predator)
What did the Non-European Ancient Scholars believe regarding Evolution?
themes related to struggle for survival among individuals and change over time, which were unknown the European scholars
Who are the most important Non-European ancient scholars regarding Evolution?
Zhuang Zhou & Al-Jahiz
What were the common views of the 19th century and earlier?
- Species are fixed (unchanged)
- Species are independent (no common ancestry)
- Earth was young (ex; 10,000 years old)
What were fossils originally believed to be?
Originally thought to be geometric forms in the rock
Who was the first to recognize fossils were remains of organisms?
Nicholas Steno (1638 - 1686)
What is Steno’s law of superposition?
Layers of rock are arranged in a time sequence, with younger layers at the top
What are Fossils?
the preserved remains (body fossils) or traces (trace fossils) of organisms from prehistoric time
What are the 3 paths to preservation?
- Permineralization
- Trapped in amber
- Frozen
What does the Fossil Record say?
Evidence that organisms from the past are not the same as we see today, giving a record of change over time within a group of related organisms
What did the rise of Geology tell us?
- There are different rock types/layers
2. the slow but continuous process of erosion and uplift
3. Earth is old
4. Fossils were confined to distinct layers
Who discovered the process of erosion and uplift?
James Hutton & Charles Lyell
Who first recognized extinction?
Baron Georges Cuvier
How did Baron Georges Cuvier recognize extinction?
Fossils resemble but are not exactly the same as modern species
What is Homology?
Species share common themes in their anatomy
What is Morphology homology?
bones in forelimbs of vertebrates
What is Embryology homology?
tail developing embryos of vertebrates
What is Molecular homology?
similarity in genes of fruit flies and mammals
What are Homologous Structures?
parallel (similar) structure in diverse organisms that were inherited from a common ancestor
What is a Vestigial Structure?
physical structure present in an organism but has no (or little) apparent function and appears to be from a functional structure in a distant ancestor
What is the Law of Succession?
extinct species were succeeded by similar species
What is a Transitional Feature?
trait in a fossil that is intermediate between ancestral (older) and derived (newer) species
What does Fossil records provide with evidence from transitional features？
that lineages have changed over time
Who discovered the inheritance of acquired characteristics?
Jean Baptiste de Lamarck
What did Lamarck believe?
- Continuous use of an organ results in its growth (and dissuse causes it to shrink)
- trait changes due to use/disuse are passed to offspring
Who discovered the Malthusian Catastrophe?
Thomas Malthus
What is the Malthusian Catastrophe?
without regulation, human population size will become too large, leading to famine/war/disease and a population crash back to subsistence levels
What advancement were made in evolutionary thought?
- Species have changed through time
- Life on Earth is ancient (allowing time for large divergences among species)
- Transitional fossils document changes in the traits of related species
- Homologous traits are common
- Closely related species often live in the same geographic area
What was “The Voyage of the Beagle”
(1831-1836)
A voyage taken by Darwin to survey geology among South America, where he collected nearly 10,000 fossils and specimens.
He was in the Galapagos Islands for only 5 weeks.
How long is Charles Darwin work cataloging his findings, conducting experiments, and working on details of his theory?
20 years
Who is responsible for the Wallace Line?
Alfred Russel Wallace
What is the Wallace Line?
An imaginary divider used to mark the difference between species on either side of the line
What 2 explorations did Wallace have?
- Exploring Brazil (1848-1852)
- Malay Archipelago (1854-1862)
Which authors published a theory on Natural Selection?
Alfred Russel Wallace & Charles Darwin (a joint-publication)
Which book complies Darwin’s research?
On the Origin of Species (1859)
What is Modern Synthesis?
overarching evolutionary paradigm that took shape by the 1940s that is generally accepted today
(reconciled works of Darwin/Wallace “natural selection” & Mendel “genetics”)
Perminerlization
minerals enter dead organic material and form an internal cast
