Evolution Flashcards
define- Theory Of Evolution
A process in which significant changes in the inheritable traits of a species or population occur over time.
The Scientific Method (5 steps)
- Observations
- Question
- Hypothesis
- Prediction
- Test
Arguments Against Evolution: Plato
An ideal and perfect form (man) does not change and variation is evidence for imperfection and is not stable.
Arguments Against Evolution: Aristole
Organisms were arranged in ascending order from simple to complex. You could not pass on to your offspring something different from what you are.
Arguments Against Evolution: Judeo/ Christian Theology
Unless man was exempt from natural law man could not have changed since man was created in the “likeness of god”.
Evidence For Evolution: From Paleontology (fossil record)
From geological strata (rock layers) or disintegration of a radioactive compound that is constant, a compound can be shown to show the fauna and flora do not remain constant.
Flora: ?
Fauna: ?
Flora = Plant Fauna = Animal
Name The 3 Arguments Against Evolution
- Plato
- Aristole
- Judeo/ Christian Theology
Name The 5 Arguments FOR Evolution
- From Paleontology
- From Comparative Anatomy
- From Biochemistry
- From Embryology
- From Patterns of Distribution
Evidence For Evolution: Comparative Anatomy
From homologous structures found in different species that share common ancestry. This provides evidence that differences from the basic structures of a given organ have resulted from modifications which reflect new adaptions to functions. i.e. from analogous structures found in various unrelated species like wings from bat, bird, insect.
Evidence For Evolution: From Biochemistry
From similarities found in DNA base sequencing among primates. This evidence suggests again progressive change and common ancestry. i.e. comparing chromosomes.
Evidence For Evolution: From Embryology
From ontogeny, which is the successive stages during the development of an animal primarily embryotic but also postnatal. Similarities among stages between organisms. This supports common ancestry. i.e. evidence of gills in embryos of all animals.
Evidence For Evolution: From Patterns of Distribution
If isolated and not able to interact, organisms even if once related, will change and form new species. Suggests that environment can pressure change in a population of organisms. i.e. Darwin’s Finch’s: finches of different environment had different traits.
CTT- Lyell (1797-1875): Theory Of Uniformitarianism
“the present is key to the past,” - fossils represent the concrete record of Earths history.
CTT- Malthus (1766-1834): Malthusian Checks
Proposed organisms produce more offspring than necessary than can survive under normal circumstances. Checks such as famine, natural disasters are important to keep populations from exploding.
CTT- Lamarck (1744-1829): Inheritance Of Acquired Traits
Proposed environment affects shape and organisation of animals.
CTT- Darwin (1809-1882): Theory Of Natural Selection
Four Points
1) the variation is already present among individuals of most populations.
2) variation is inherited
3) populations produce more than environment can handle
4) traits best adaptive survive and leave more offspring
What does Natural Selection result in?
Determines the fittest individuals. fitness refers to ones relative gene pool of the next generation.
Alleles
alternate forms of a gene. i.e dominant or recessive.
Genotype
Alleles found on the chromosome of an individual
Gene Pool
Total number of alleles present in a population and can change over time.
What do these determine:
AA Homozygous Dominant
Aa Heterozygous
aa Homozygous Recessive
The phenotype of an individual.
Micro-evolution
Changes in gene frequencies and phenotypic traits within population; may result in a new species.
Speciation
A process in which a new species arise.
Reproductive Barrier
Anything that prevents species from interbreeding.
Phylogenetic Tree
branching diagram that represents the evolutionary relationship among species or groups.
Cladistics
determining the evolutionary relationship of species based on shared derived traits.
Cladogram
Phylogenetic tree that classifies organisms based on shared derived traits.
Punctuated Equilibrium
A theory of how evolutionary change occurs. In this theory most species have little evolutionary change through periods of time.
i.e. when sea animals who breed and die for many years have an environmental change of sea levels, their bodies must change to accommodate this change.
Gradualism
A theory assuming that change comes gradually or that variation is gradual in nature.
i.e. pigment of tiger stripes develop over time.
Convergent Evolution
The process whereby organisms not closely, independently evolve similar traits as a result of having to adapt to similar environments.
i.e. butterflies and birds
Co-Evolution
Evolution involving a series of reciprocal changes in two or more non breeding populations that have a close ecological relationship.
i.e. crab and algae
Parallel Evolution
When two unrelated species evolve with the same traits while living with the same type of environmental conditions.
i.e. old frogs compared to new frogs have differences, later share similarities
Phyletic Speciation
Suggests that abrupt mutations in a few regulatory genes occur after species have existed for a long time and results in the entire species shifting to a new species
Divergent
Suggests gradual accumulation of small genetic changes results in a sub species that eventually become separate species.
3 Patterns of Evolution
- Divergent
- Convergent
- Co-Evolution (parallel)
Microevolution
Changes in gene frequencies in phenotypic traits within population; may result in a new species
Macroevolution
Evolution occurring over geologic time that results in the formation of new taxonomic groups
Bottleneck effect (genetic drift)
Changes to allele frequencies as a result of chance: these changes are more pronounced in small populations
Founder effect (genetic drift)
Genetic drift that results when a small number of individuals separate from their original population and find a new one
4 Factors that influence allele frequencies
Genetic Drift, Gene Flow, Mutation and Natural Selection
Homology
a similarity often attributable to common origin
Analogy
a comparison of two things based on their being alike in some way
Vestigial Structure
A remnant of structures that may have had important functions in ancestral species but none now.
