Lecture 2: History of Evolution Flashcards
(59 cards)
Biological essentialism
a viewpoint that attributes certain characteristics, behaviors, or roles to individuals based on their biological makeup, particularly their sex or gender
What was the pre-Darwinian view?
Variation is accidental imperfection
Uniformitarianism
The same geological processed operated in the past as in the present. Geological data can be explained by causes that we now observe
Who championed uniformitarianism?
James Hutton and Charles Lyell
Catastrophism
Sudden, violent and short-lived events were responsible for the current state of the earth
What did Georges Cuvier believe?
He recognized that fossil forms were likely extinct. He established extinction as a fact
What theories did Lamarck, Jean-Baptiste Pierre, and Antoine de Monet develop?
Theories of phenotypic evolution and speciation
Theory of phenotypic evolution
Traits acquired during the course of an individual’s lifetime were passed on to offspring.
Ex: lengthening of giraffe’s necks, thickening of blacksmith’s arms
Which theory addresses the inheritance of acquired characteristics?
Lamarck’s theory of phenotypic evolution
Lamarck’s hypothesis for giraffes
Giraffes evolved long necks because individuals in ancestral giraffe populations stretched their necks to reach higher leaves on trees. This stretching led to the elongation of their necks, and this acquired trait was then passed on to their offspring. Over time, this process resulted in the evolution of giraffes with long necks.
Darwin hypothesis for giraffes
Giraffes with longer necks were more likely to survive and reproduce because they could access more food from taller trees. Over successive generations, the genes for longer necks became more common in the population through the process of natural selection
Theory of speciation
Species originate from spontaneous generation and have not originated from common ancestors
Where are the species and common ancestor on a bifurcating tree of life?
Species: tips
Common ancestor: root
How does natural selection play a role in the Peppered Moths example?
In the 18th century, the white form of the moth was the only form known.
In 1848, dark moths were discovered as they were camouflaged on trees where soot from coal-burning had darkened tree bark.
After coal-burning decreased in the 1960s, the white form became prevalent again
What are the 5 components of Darwin’s Origin of Species?
1) Evolution
2) Common descent
3) Gradualism
4) Population change
5) Natural selection
What is common descent?
Tree of life
What is gradualism?
Slow incremental change with intermediate forms
What is population change?
Evolution occurs by changes in the proportions of individuals within a population that have different inherited characteristics
What is natural selection?
Changes in proportion of individuals with different characteristics are caused by differences in their ability to survive and reproduce
Who independently conceived natural selection?
Alfred Russell Wallace
What did Alfred Russell Wallace spur Darwin to write?
The Origin of Species
Who is the father of biogeography?
Alfred Russell Wallace
What is Wallace’s Line?
Major biogeographic barrier between Australasia and Asia
What does Wallace’s Line tell us?
Many groups of organisms are found only north or south of this line
