Lesson 3: History of Evolutionary Biology (ppt) Flashcards
one of the most influential text of this century
Origin of Species
father of Darwin
Richard Darwin
- grandfather of Darwin
- also a doctor and a prominent scholar who was already thinking about evolution
Erasmus Darwin
- encouraged students to make observations of their own, rather than being spoon-fed
- botany professor Charles Darwin became close to
Rev. John Henslow
who’s geology course did John Henslow encourgae Darwin to study
Adam Sedgwick
ship sent by British Navy to chart coastline of South America
HMS Beagle
where did Darwin make a major find of fossil bones of huge extinct mammals in cliffs beside modern seashells, indicating recent extinction with no signs of change in climate or catastrophe
Punta Alta in Patagonia
Archipelago of volcanic islands distributed around the equator in the Pacific Ocean, 972 km west of contintental Ecuador
Galapagos Islands
what did Darwin conclude in the Galapagos Islands when he saw that populations were related, but were slightly different on each land
populations descended from a common ancestor
when did Darwin disembark from the Beagle in the Galapagos
September 17, 1835
- told Darwin that the tortoises also differed from island to island
- acting governor of Galapagos
Nicolas Lawson
“Species might not be fixed entities, but are __ __ __”
changing over time
how did the mockingbirds differ from island to island
- size
- shape
- color
birds were not independently created
branching, tree-like thinking
Significance of the HMS Beagle Voyage
- amassed collections to study later
- exposed Darwin to geological formations, fossils embedded in strata
- exposure to animal diversity, related populations within species living in different habitats
Exposure to animal diversity, related populations within species living in different habitats:
- Species are not immutable fixed entities
- organisms are related by common ancestry (tree-like branching)
- they are changing and branching in response to the environment (adaptation)
scientific context was in place for development of theory of evolution
mid-1800s
Influence on Darwin:
geology
Charles Lyell’s Principles of Geology
Influence on Darwin:
Lamarck’s
concept of adaptation, inheritance of acquired characteristics
Influence on Darwin:
Malthus
competition within species and the struggle for survival
the first scientific theory of evolution
inheritance of acquired characteristics
made the first scientific theory of evolution, inheritance of acquired characteristics
Jean-Baptiste Lamarck
what did Thomas Malthus write
Essay on the Principle of Population
From Malthus, what did Darwin think
idea of competition and the “struggle for survival: as a component of Natural Selection
came up with the diea of natural selection independently
Alfred Wallace
when did Darwin publish Origins
1859
What did Alfred Russel Wallace write
On the Tendency of Varieties to Depart Indefinitely from the Original Type
where did Alfred Russel Wallace observe natural selection
Malay Archipelago
when did Wallace send Darwin a copy of his manuscript
1858
change through time occurs at the __ not the __ level
- population
- organism
main cause of adaptive evolution
natural selection
Darwin’s main points
- organisms evolve
- common descent
- gradualism
- population speciation
- natural selection
species arise from common ancestors, in a tree-like branching process
common descent
changes are gradual (we now know that this is not always true)
gradualism
change in proportions of individuals having a trait in a population
population speciation
Pattern of Evolution acc. to Lamarck
linear progression
Pattern of Evolution acc. to Darwin
tree-like branching process
mechanism of evolution acc. to Lamarck
inheritance of acquired traits - individual evolution
mechanism of evolution acc. to Darwin
evolution at the population level via natural selection
one species turns into another
transmutation of species
individuals with this mutation survive and leave more offspring
greater fitness
example of nonadaptive evolutionary forces
genetic drift
father of genetics
Gregor Mendel
principle stating that the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors
Hardy-Weinberg equilibrium
traits in Mende’s principle
particulate traits
traits in Darwin
continuous traits
thought that evolution required only mutations and passing on of discrete traits
mutationists
thought that evolution required only natural selection on continuous variation
Darwinists
a trait that has distinct values, rather than a range of phenotypes, usually encoded by one or a few genes
discrete trait
ex. of discrete trait
- number of fingers
- color of Mende’s peas
- sickle cell anemia
- ABO blood type
- number of eggs in a bird clutch
- presence/absence of human widow’s peak
- presence/absence of dimples
trait that has a continuum of phenotypes and is encoded by multiple genes
quantitative (continuous) trait
ex. of quantitative (continous) trait
- body size
- height
- weight
- intelligence
- running speed
offspring gain characteristics of both parents
blending inheritance
proponents of the mutationist theory
- Hugo de Vries
- Thomas Hunt Morgan
What caused the mutationists vs darwinists problem
- binary thinking (black or white thinking)
- inability to see overarching mechanism
states that most evolutionary changes at the molecular level are caused by random genetic drift of selectively neutral nucleotide substitution
neutral theory of molecular evolution by Kimura
synthesis of population genetics (integrate the roles of mutation, selection, genetic drift, paleontology, systematics)
Modern synthesis
Modern synthesis is also known as
Synthesis of Evolution and Genetics
The modern synthesis is among the __ __ __ of the century
greatest scientific revolutions
Some Key Tenets of the Modern synthesis
- populations - units of evolution
- Mendel vs Darwin: continuous traits are also coded by particulate genes
- Mutation vs Selection: mutations are sources of genetic variation upon which selection acts
- natural selection and mutation are not the only evolutionary forces
- microevolutionary processes lead to macroevolutionary changes
example of other evolutionary forces
- genetic drift
- migration
microevolutionary processes
- drift
- selection
- mutation
“changes in proportion in a population could occur via random genetic drift”
Sewall Wright
