Population Change Flashcards
Evolution
Consists of the idea that species could change and evolve over time which were being shared in the 18th century
- Prior to this, it was more widely believed that species were unchanging
Evolutionary studies were thought to be influenced by different academic fields:
G.E.P
- Geology - an understanding of the age and complex history of Earth
was being developed - Economics - essays on limited resources and competition
- Paleontology - evidence of fossils unlike animals seen currently
Jean Baptiste Lamarck
IoAC
- Org —> u and m their t
- Changes —-> p onto o
Proposed Inheritance of Acquired
Characteristics
- The idea that organisms could use and modify their traits during life
- These changes could then be passed onto offspring
Darwin & Wallace
- M for e —> voyages in the P
- Darwin»_space; SA & G
- Wallace»_space; SE A & B
- Obs traits —> island chains
Both came up with mechanisms
for evolution on separate voyages
in the Pacific
- Darwin- South America & Galapagos
- Wallace- SE Asia & Brazil
Both observed different traits
on similar animals across
island chains (archipelagos)
Natural Selection - 3 Principles
- T»_space; inherited
- More O»_space; produced»_space; competition
- T vary»_space; some favor. for surv.
Based on three principles
1.Traits are inherited by offspring
2. More offspring are produced than
can survive, leading to competition
for resources
3. Traits of offspring vary with some
of those traits being more favorable
to survival
Natural Selection - Descent with Modification
- T enhance surv.»_space; passed»_space; c in pop.
Traits that enhance survival are
passed onto next generations and
can lead to changes in populations
Genetic diversity
M & SR
- cross over during Mei & comb of all.»_space; diversity
- mut. to g»_space; b, h or n
Diversity is based on mutations and sexual reproduction
- Cross-over during meiosis and combinations of alleles from parents can lead to genetic diversity
- Mutations to genes can be beneficial, harmful, or neutral
Adaptation
Consists of traits that aid the survival and reproduction of an organism
- Depends on the environment the organism is living in
Adaptation - Divergent Evolution
Is when species have evolved from a common ancestor
Adaptation - Covergent Evolution
- Sim E»_space; sep unrelated species evolving from sim adap
Similar environmental pressures can lead to separate (unrelated) species evolving from similar adaptations
- Similar adaptations or traits can be analogous structures
Homologous Structures
- Sim in s & a loc»_space; shared ancestry
- No sim function
Consists of similarity in structure and anatomical location indicates shared ancestry
- May not necessarily have similar function
Genetics
- Integ w evolution in the ___
- Gen of pop»_space; obs»_space; evolution of g
- Beneficial Ph»_space; increase over time»_space; A F increase
Integrated with evolution in the mid-20th century (modern synthesis)
- Genetics of a population can be observed in relation to the evolution of a specific group
- Beneficial phenotypes can increase through time, resulting in an increase in allele frequency
Factors that can affect Allele Frequency
NS. M. GD. GF
- Natural Selection
- Mutation
- Genetic Drift
- Gene Flow
Natural Selection - Effect on Allele Frequency
Ph»_space; survival
Genetic ph»_space; passed on
Some phenotypes can be useful for survival
- If the phenotype is genetic in origin, trait can be passed onto offspring
Mutation - Effect on Allele Frequency
Change in DNA sequence in gene can result in new phenotype
- If phenotype is beneficial, new gene can be passed onto offspring
