Lesson 1 Flashcards
a discipline of biology concerned with the processes & patterns of biological evolution, especially in relation to the diversity of organisms and how they change overtime.
Evolutionary Biology
- earth is ancient
- all organisms share a common inheritance
- natural events can be explained by discoverable natural laws
Modern Theory of evolution
saw species as unchangeable and arranged in hierarchical from most imperfect to most perfect (expressed as the Great
Chain of Being).
Idealistic Philosophy
proposed mechanism - evolution by Natural Selection
Charles Darwin and Alfred Russel Wallace
Natural Selection tied to interactions :
a. between organisms
b. between organisms
and their environment
Mechanism of inheritance based on what?
genetic code
Began with Latin term Evolutio, (17th century) which means
unrolling, describe as unfolding the parts and organs
used evolution to describe the preformed development of the adult in egg
Albrecht von Haller
developed the concept of preformation
Charles Bonnet
miniature adult was contained within the egg/male seminal fluid
preformists: ovists and spermists
classical expression belief of spontaneous generation - rat evol
Johann von Helmont
gradual origin of invertebrate groups in successive strata of rocks
Robert Grant
gradual improvement of aquatic organisms to land
Charles Lyell
spontaneous generation - fly evol
Francesco Redi
Lazzaro Spallanzani
broth experiment
Louis Pasteur
fermentation process used in beer and wine
- theory of evolution by means of natural selection
- published the origin of species
Charles Darwin
Individuals who possess heritable traits that make them better adapted to their environment are more likely to survive and to produce more offspring than to individuals who are less adapted to the environment.
better adapted, more likely to survive and to produce, less adapted
why charles darwin became a controversial scientist?
considered dangerous in 19th-century England because it threatened the prevailing views of the Anglican Church and society at large
changing environment - presence of hereditary variation - differential reproduction - modification of existing character
gregor mendel - pea plants
Mendelian Genetics - discovery of mutation (saltation)
first step of evolution (affects individual)
Mutation
change in gene frequency through time (affects population)
Evolution
darwin and mendel
mendelism + darwinism
Neo-darwinism
the genetic variation in population will remain constant from one generation to the next in the absence of disturbing factors (law predicts that both genotype and allele frequencies will remain constant because the are in equilibrium)
Hardy - Weinberg equilibrium
5 conditions must hold in order for allele and genotype remain constant over many generations:
1.no mutation
2.no migration
3.larger population
4.random mating
5.no natural selection
population frequency within a population, under the influence of:
selection
mutation
gene flow
genetic drift
1.original theory of Charles Darwin to explain the origin of new specie
2. accumulation of continuous variations causes changes in individuals to form new species
3. believes in the selection of individuals on the basis of accumulation of variation
4. darwinism does not believe in isolation
5. can explain the origin of new characters
6. darwinism cannot explain the persistence of forms in the unchanged conditions
Darwinisim (Natural Selection)
- modification of the original theory of Darwin to remove its shortcomings
- mutations are believed to help form new species
- Variations accumulate in the gene pool and not in the individuals
- incorporates isolation as an essential component of evolution
- can explain the occurrence of unchanged forms over million of years
- normally only those modification are transferred to next generation which influence germ cells or where somatic cells give rise to germ cells
neo-darwinism
the process organisms better adapted to their environment tend to survive and produce more offspring
natural selection
selective breeding
choose traits and breed organisms for that trait
no isolation - sterile hybrid is formed
artificial selection
explains traits that seem to have no survival benefit
“fitness” isnt just about survival, its about reproduction
ex. peacock
sexual selection
female choose sexy males so their sons can be sexy too
- fortunate few males who wins to the copulations
sexy son hypothesis
honestly attractive
Good genes
the random change in allele frequency - occurs in small populations that break away from larger groups
genetic drift
drastically reduces the size of population. (environmental disaster, habitat destruction)
population bottleneck
evolutionary strategy that favours the reproductive success of an organisms relatives, even at a cost to the organisms own survival and reproduction
kin selection
look like altruistic behaviour whose evolution is driven by kin selection
kin altruism
describes natural selection operating between groups of organisms, rather that between individuals
group selection
Evolution is the change in the genetic make up of populations over time. All living things change. Evolution is a fact.
the mechanism of the evolution ( how it happens) is a theory.
facts of evolution
fossil forms they left behind
genes, chromosomes and molecular features that connect them
