Evolution Flashcards
Evolution (Darwin)
Gradual change of heritable traits in a population across generations, eventually generating species over time.
Modern Evolutionary Synthesis
A change in allele frequency over time.
Homology
same structure, different function
Analogy
same function, different structure
Gregor Mendel
Characteristics pass from parent to offspring in form of discrete packets he called genes
Population
Unified and defined by its gene pool
Species
Interbreeding groups of populations
Gene pool
Total aggregate of genes in a population at one time
Allele
Alternative forms of a gene
Genotype
Genetic makeup of an individual (allele they carry for traits)
Homozygous
Identical alleles for a given trait
Heterozygous
Have more than 1 different alleles for a given trait
Phenotype
Physical expression of the alleles
Natural Selection
- DNA
- RNA (read by)
- Protein
- Phenotype
- Changes in anatomy, physiology, and/or behavior
- Differential reproduction and survival of individuals in a population
Microevolution
A change in the frequency of genes and chromosome configurations in a population
Mutation
Sudden change in:
- gene
- chromosome
- an entire set of chromosomes
Types of Mutations
Down’s syndrome - trisomy 21
Klinefelter’s - XXY
Turners - XO
Cri du Chat- 5p
Changes in chromosome number
Changes in gene location (translocations)
Point mutations
Silent - doesn’t affect the gene
Missense - slight alteration
Nonsense - stops protein from being produced
Frame shift mutations
Deletions
Insertions
Trinucleotide repeats
DNA getting repeated
Unfavorable mutations cause genetic disorders
- Sickle cell anemia
- Huntington’s disease
- Cystic Fibrosis
- Tay Sachs
Principle of Natural Selection
- Organisms that experience the most reproductive success will produce more offspring than other individuals in the population.
- Descent with modification: natural selection acting on enough traits across a sufficient number of generations can produce a new species
Examples of natural selection
- Antibiotic resistance in bacteria
- Sickle cell anemia and resistance to malaria
Vestigial structures
An anatomical feature or behavior that no longer seems to have a purpose in the current form of an organism (ex: wisdom teeth)