Download Evolution and symbiogenesis

EVOLUTION AND
SYMBIOGENESIS
Refining Darwin’s Theory of Evolution
ABSTRACT
 Evolutionary theory is not static; it is continually being modified
and refined.
 Darwin’s theory of evolution by descent through modification is
currently the predominate theory in evolutionary science.
• This is because it is a flexible theory open to modification and
refinement.
 Symbiogenesis seeks to modify and refine Darwin’s theory of
evolution.
BACKGROUND
BACKGROUND
 Life is persistent and pervasive in its ability to exist in nearly all of
the Earth’s environments.
• This ability is due to life’s ability to change and adapt.
 Change and adaptation is achieved through evolution.
• Darwin’s theory of evolution best explains the means by which
species change and adapt.
DARWIN’S THEORY OF
EVOLUTION
 Population of species are able to change over time due to three
interacting conditions.
• A given characteristic is variably distributed throughout a population
of a single species.
• This characteristic is heritable from parent to offspring via
reproduction.
• Those organisms with the greatest positive aspect of this
characteristic survive to reproduce in greater numbers than those
organisms with the less positive aspect of characteristic.
• Darwin referred to this as natural selection.
THE THEORY OF
SYMBIOGENESIS
 Evolution occurs due to the long-term, stable symbiotic
association of two unrelated organisms, and or their genomes.
• These associations lead to abrupt evolutionary novelty.
 Natural selection still actively selects those organisms that are fit
enough to survive.
DARWINISM VS.
SYMBIOGENESIS
 The role of accumulated change via mutation in Darwin’s theory is
drastically overrepresented in evolutionary theory.
• Evolution occurs due to the long-term symbiotic interactions of two
different organisms.
SIGNIFICANCE
SIGNIFICANCE
 Evolution occurs relatively rapidly through the acquisition of
foreign genes or genomes.
 The acquisition of genes can be immediately profitable or
profitable later in the organism’s or species existence.
 Most species are actually a consortium of several species.
 The theory of symbiogenesis requires a reassessment of all
previous evolutionary research.
METHODS
METHODS
 Organisms must be in the same place at the same time.
 They must be behaviorally induced to interact.
• Grass requires sunlight to grow and thus grows best in plains, cows in
turn inhabit those same plains.
 The interactions must be metabolically beneficial to both organisms.
 The products of both organisms must beneficially interact for both
organisms.
 The genes of one organism must be incorporated by the other
organism.
METHODS OF DETECTION
 Gene sequencing and analysis are the main modes of detecting
symbiogenesis.
• Methods of analysis include examining substitution rates,
phylogenetic incongruence, and scanning for polymorphic sites.
• The different methods of analysis often lead to imperfect and
contradictory results.
RESULTS
RESULTS
 Due to the lack of limitations on what counts for symbiogenesis, the
full extent of life’s complexity is available for analysis.
• This complexity is difficult to encompass fully in a formal definition.
 Species can adapt relatively quickly to varying environments through
the highly heritable and acquirable nature of beneficial genes, as seen in
several experiments with E. coli.
 The specific functioning of an integrated organism can be used to
determine phylogenetic histories.
ETHICAL
IMPLICATIONS
ETHICAL IMPLICATIONS
 If the evolution of species is abrupt and heavily dependent upon
associations as symbiogenesis theorizes, a reevaluation of all past
evolutionary research is necessary.
CONCLUSION
CONCLUSION
 The theory of symbiogenesis does not stand opposed to
Darwinian evolution.
 Symbiogenesis seeks to modify the concept of how evolution
occurs among species, not how they are selected to propagate.
 The theory of symbiogenesis requires further refinement and
support before it can be added to the forefront of evolutionary
practice.