Natural Selection Flashcards
Lamarck’s Theory of Evolution
Species evolve through use and disuse and the inheritance of acquired traits
Differential survival
When completion for limited resources results in indivals with more favorable phenotypes surviving wail those with out die off
Evolutionary fitness
Measured by reproductive success
Convergent evolution
Similar selective pressures = similar phenotypic adaptations in different population or species
Population
A group of organisms all of the same species living in the same area
Gene pool
A population genetic makeup
Bottleneck effect
A sudden change in the environment that may drastically reduce the size of a population. The resulting gene pool may no longer reflect the original population gene pool
Founder effect
When a few individuals are separated from the larger population and form a new population. This can affect allele frequency in a population
Geological evidence
Fossils and radioactive dating
Physical evidence
Anatomical and physiological analysis
morphological homologous
the phenotypic similarity in the structure of organisms that are due to a shared ancestry. Evident in the physical form and structure of organisms
Homologous structures
anatomical features found in different species that are not exactly the same but similar since they where inherited from a common ancestor. Share similar underlying anatomy but preform different functions
Vestigial structures
homologous structures that have lost there original function ( ex: snakes still have pelvis and leg bones that are from there legend ancestors.These structures represent features passed down from a common ancestor even if they are only found in an embryo
Biochemical comparative analysis
DNA or amino acid sequences provide evidence for evolution and common ancestry
The more similarities in the sequence the more similar the ancestry/ most recent divergence
Mathematical/ Experimental Evidence for Evolution
◦ comes from population genetics models like Hardy-Weinberg
◦ Evolution experiments can also be used as evidence (EX: real time evolution in antibiotic resistance bacteria
Evidences for common ancestry
membrane bound organelles, linear chromosomes, Genes that contain introns
Endosymbiotic theory
Explains how eukaryotic cells evolved from a common ancestor
Extant species
Species that are still alive
