Mechanisms of Evolution Flashcards
Aristotle
284-322BC Scala naturae Diversiteit in natuur Alle soorten zijn onverandelijk Typology
Buffon
1707-1755
Typologist
Praate over evolutionaire problemen
James Hutton
1729-1797
Gradualism in geologische formaties
Erasmus Darwin
Overerving van verworven characteristics
Thomas R. Malthus
1766-1834
Essay on population 1798
Rate of population increase out of proportion to the increase of its subsistence means (resources)
Charels Lyell
1797-1875 Influential geologist Revived theory of Hutton Earths feature shaped over a long period of time Strata in geological sediments
Carolus Linaeus
1707-1778 Natural Theologian, Botanist, Typologist University of Upsala, Sweden Vader van de taxonomy Binomial nomenclature: (genus-species) Hierarchic system of classification leading to Phylogenies
Jean Baptiste Lamarck
1744-1829 Extraordinary biologist Philosophie zoologique (1829) First to propose organic evolution Dynamic rather than static nature Domestication Identified lines of descent Mechanism: Use & Disuse Inheritance of acquired char
Charles Darwin
1809-1882
Study, Clergyman and naturalist
5 year collection expediton HMS beagle 1831: South am, Galpagos
Observed adaptations of animals in different eviroments
Origins of spieces (1859)
Beagle Journey: Galapagos Islands
Equatorial arhcipelago in The Pacific Ocean
Ecuador
Many endemic species
Galapagos Island spiecies
Unique animals that resemble mainland species
Adaptation and speciation tied together
Darwins writing
Almost scooped by Alfred Russel Wallace
Papers of Darwin & Wallace published in kournal of the linnean society 1858
On the origin of species by means of natural selection 1859
The heart of Darwin’s theory
Individual variation of inherited characteristics
More offspring than survive
Adaptation to local environment
Differential reproductive success: natural selection
Darwin: Sources of variation in a population
Crucial element of Dawins theory, no clue where this variation was coming from
Spontaneous emergence?
Use and disuse?
Environmentally induced variation is inherited
Natural Selection
Offspring with best traits have higher reproductive success
Favorable traits accumulate over time
Evolution is virtually irreversible
Modern Synthesis
1930-40: unification of genetics & evolution
Integrated Darwinism with discoveries in many fields
Three mayor developments
- Experimenal genetics: Artificial selection
- Mathemetical genetics: gradualism, punctuated equilibrium theory
- Population genetics: geographic variation, genetically induced & adaptive
Mechanism of Evolution: Modern
Genetic variability
Natural & sexual selection
Natural selection
Genetic variability, mutations
Acquired char cannot be inherited
Natural Selection is a consequence of interaction with environment
Individuals & populations are units of evolution
Fitness+inclusive fitness
Genetic drift: gradualist
Punctuated equilibrium
Leading 20th century evolutionists
Ernst Mayr
Theodosius Dobzhansky
George Gaylord Simpson
Ernst Mayr
Founder effect
Theodosius Dobzhansky
Nothing in biology makes sense except in the light of evolution
Worked on genetic basis of evoluition
1930: population genetics
Integrated Medel’s genetics with evolution
Population
Group of interbreeding conspecific individuals
Smallest unit that can evolve
Evolution is change in gene or allele frequency in a population
Natural selection acts at the level of populations
Genetic drift:
- Mutation driven
- population bottlenecks: near extinction events
- Gene flow: immigration-emigration
- founder effect
Modern study of evolution
Fosil record
Comparative anatomy & Embryology
Bio geography
Comperative biochemistry & molecular biology
Experiments in evolution: Lab exp, sim, math mod
Convergence
Evolution leading to similarity between non-related organisms due to similar functional adaptation
Homoplasia
Analogy
Similar function or anatomy without phylogenetic connection
Homology
Similarity between structures due to common ancestry
Comparative embryology
Similar stages of development
Vertebrate gill slits
See S.J gould
Stephen Jay Gould on evolution and its teaching
Changes in the environment, climate or local ecology, diseases, cataclysmic events, etc. can bring about rapid evolutionary change or extinction
This could have happened as well when human ancestors with ape morphology and brains were confronting environmental changes in Eastern Africa. This could have ended this phylogenetic line. As it turned out, it gave rise to the appearance of bipedal humanids that were adapted to these arid habitats.
