Chapter 11- Evolution Flashcards
Evolution
Descent of modern organisms with modifications from predicting life- forms; one generation to the next
Buffon
Animal evolution
Hutton
Gradual Geological Change
Lamarck
Mechanism of species change
Curier and Smith
Catastrophes and sequence of fossils
Lyell
The greater age of earth gave more time for gradual change in species
Darwin
Evolution and natural selection
Wallace
Evolution and natural selection
Mechanism of evolution
Darwin and Wallace record data about animals and plants in the tropics and wrote about evolutionary thought
Natural selection
Greater relative survival and reproduction with favourable heritable traits resulting in evolutionary change
3 principles of natural selection
Characteristics passed from parent to offspring
More offspring are produced than able to survive
Competition for resources affect survival of offspring
Variation
Differences of individuals.
Sexual selection and mutation
Adaptation
Aids survival and reproduction of in the present environment or “match”
Divergent evolution
2 species evolve in different directions from a common point or species
Convergent evolution
Similar structures arise through evolution independently in different species; similar in function, not structure
Modern Synthesis
Combining knowledge of genetics and evolutionary thought
MICROevolution
Gradual changes of population over time
MACROevolution
Gives rise to a new species and higher taxonomic groups; widely diverged
Evidence for Evolution
Fossils
Anatomy- homo/ analogous
Embryological similarity
Modern biochemical and genetic analyses
Homologous Structures (ancestry)
Differ in function but has similar anatomy, descended from common ancestors
Vestigial Structures (ancestry)
No apparent purpose; homologous to functional structures and is evidence for evolution
Analogous Structures (convergent evolution)
Similar functions, superficial similar appearance but very different anatomies (similar because of similar environmental pressures)
Embryological similarity (ancestry)
1800s Karl Von Baer similarities of vertebrae in the embryo
Biochemical and genetic analyses
Molecular similarities of diverse organisms; determined by nucleotide sequencing
Nucleotide
Phosphate bonded to a sugar, bonded to a nitrogenous base (ATCG)
Molecular similarity
DNA=RNA= Amino Acids= proteins
Can work backwards from protein to determine original DNA sequencing
Universal biochemical processes
RNA- almost same code to translate genetic info into proteins
Same set of 20 amino acids to build proteins
ATP as cellular energy carrier
Alleles
One of several alternative forms of a particular gene
Genotype
Genetic composition of an organism
Phenotype
Physical characteristics of an organism
Gene pool
Total of all alleles of all genes; total of all alleles that the gene occurs in
Allele Frequency
Any given gene, relative proportion of each allele of that gene
HW equilibrium principle (4factors)
- No mutation
- Not genetic drift
- No gene flow
- Must be natural selection
Causes of gene flow
(Mike Gives Gum Never)
Mutations
Gene flow
Genetic drift
Non-random mating
Mutation
Change in base sequence of DNA; alters appearance or function (greater genetic diversity)
Gene Flow
Movement of alleles; migration of individuals
Genetic drift
Change in allele frequency of a small population purely by chance
Bottleneck and founder effect
2 types of genetic drift
Nonrandom mating
Organisms seldom strictly mate randomly
Inbreeding- stay in place of birth due to lack of mobility
Assortative mating- mate only with others of their species, looking like themselves
Beneficial/ nonbeneficial genotypes
Most populations are not equilibrium so it can pass harmful mutations, detrimental over the long run like inheriting recessive genes or abnormalities for certain diseases
3 principles of Natural Selection
Unequal reproduction
Acts on phenotypes (adaptation)
Acts of selection
Competition
Predator/ prey relationships
Sexual selection (nonrandom mating)
Competition
Interactions with individuals who attempt to utilise a resource limited relative to the demand for it
Certain genetic traits being selected for
Ex body/ antler size ; tusk/ beak length
Predator/ prey relationships
2 species interact and each exerts strong selection of the other. One evolves a new feature or modifies and old one, other gets new adaptations in response COEVOLUTION
Sexual Selection
Cause of evolution
Choice of mates by one sex is selective agent
Darwin- sexual contests among males or female preference for male phenotype
3 ways of Selection
Directional
Stabilising
Disruptive
Directional selection
Extreme value of a trait and selects against both average individuals at the opposite extreme (slope)
Stabilising selection
Average value of a trait and selects against individuals with extreme values (bell curve)
Disruptive selection
At both extremes of a trait (half and half)
Systematics
Reconstructing phylogenies with naming and classifying species
3 main domains
(Erin Ate Eggplant)
Eukarya: animals, plants, fungi, protist
Archaea: prokaryotes distantly related to eubacteria (domain, Genus, species)
Lineman taxonomy
Carl Von Linne; basic foundation for our modern classification system
Domain= Kingdom= Phylum= class= order= family= genus= species
Phylogenetic trees
Diagram that shows evolutionary pathways and relationships
Homologous Structures
Clues of common ancestors (wings, fins, arms)
Analogous Structures
Similar appearance, different in function
Phylogeny
Evolutionary history of a group of species
Why classifications change over time
New information is discovered
Difficulty applying definitions to organisms
