Download Evolution

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Genome (book) wikipedia, lookup

Microevolution wikipedia, lookup

Designer baby wikipedia, lookup

Gene expression programming wikipedia, lookup

Quantitative trait locus wikipedia, lookup

Gene wikipedia, lookup

Gene expression profiling wikipedia, lookup

Population genetics wikipedia, lookup

History of genetic engineering wikipedia, lookup

Genetic engineering wikipedia, lookup

Human genetic variation wikipedia, lookup

Biology and consumer behaviour wikipedia, lookup

Behavioural genetics wikipedia, lookup

Heritability of IQ wikipedia, lookup

Genome evolution wikipedia, lookup

Minimal genome wikipedia, lookup

Epistasis wikipedia, lookup

Genetic drift wikipedia, lookup

Transgenerational epigenetic inheritance wikipedia, lookup

Polymorphism (biology) wikipedia, lookup

Koinophilia wikipedia, lookup

Group selection wikipedia, lookup

Dual inheritance theory wikipedia, lookup

Twin study wikipedia, lookup

Genetically modified food wikipedia, lookup

Life history theory wikipedia, lookup

Transcript
Evolution
&
Natural
Selection
First thoughts on the idea…
• “Acquired Traits”
• Once a structure
is modified it is
passed onto
offspring
Lamark
Charles Darwin Thoughts
(Galapagos Islands)
• Evolution occurs
– Change over time
• Evolution is due to
Natural Selection
Darwin’s Finches
• Finches had different beaks that were
specialized for what they ate
– Each had their own NICHE
• All of these finches were descendents
of the same finch
What is Evolution?
• Gradual change
over time
• Descent with
modifications
Cladogram
– Newer forms (in
fossils) are the
modified
descendants of
older species
Natural Selection
• Organisms with
favorable traits
reproduce more
than those with out
these traits
• Traits = Variation =
MUTATIONS
Variation / Diversity
• Slight differences in
the appearance of
organisms
(phenotypes)
– Sexual reproduction
– Gene recombination
• IMPORTANT: if
environment
changes SOME
organisms will survive
What determines Natural Selection?
• ENVIRONMENT
• In order to be
beneficial the
trait must help the
organism live in its
environment
• Based on
phenotypes
Adaptation & Fitness
• Adaptation –
increasing # of
favorable traits
• Fitness – An
organisms genetic
contribution to
offspring
• High fitness = well
adapted
Natural Selection & Genetic Change
• Natural selection can
not occur without
genetic variation
• Organisms that have
beneficial traits will
pass those traits to
their offspring
Fitness & Genes
• Each generation
has more
individuals with
the genes that
make them “fit”
• The frequency of
these alleles
increases over
time
Competition
• Because
resources (food,
space…) are
limited, organisms
compete for them
• Only the most fit
will compete
successfully and
reproduce
Lethal Genes
• Genes that cause
death
• How can these
genes exist?
• Heterozygous
individuals keep
these genes in the
gene pool
– Total genetic info in
population