Evolution: introduction
- Created by: megknox
- Created on: 03-01-20 15:38
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- Evolution
- Primeval Soup
- random combination of molecules, nearly all trivial but ONE could REPLICATE itself
- Replicator: not always perfect, sometimes produces slightly different versions
- Replicators COMPETE for resources so accumulated changes, e.g. shells, to help. Humans are survival machines used by replicators to survive
- Replicator: not always perfect, sometimes produces slightly different versions
- random combination of molecules, nearly all trivial but ONE could REPLICATE itself
- Gene
- a unit of evolution, modern version of the replicator. Passed on to next generation. GENES ARE LONG LASTING
- Fast Evolution
- when populations are large, selection pressure is strong
- Slow Evolution
- example of Coelacanth (fish) which have been the same for 150m years
- Evolutionary Trade-off
- organisms cant invest in everything, they invest in one trait or another
- a trade-off situation is where to gain an advantage, you must pay a price
- example: Large brains, use up lots of energy, make childbirth difficult, easily damaged
- Genetics
- Genotype: genetic material, combination of alleles inherited
- Phenotype: observable characteristics which interact with environment
- Chromosome: genes are located on chromosomes, occur in matches pairs, humans = 23 pairs
- Allele: different forms of the same gene
- Epigenetics
- mechanisms which influence the expression of genes
- DNA Methylation
- Histone Remodelling
- Cell Division
- MEIOSIS
- Produces gametes
- MITOSIS
- all cell division in the body
- DNA unravels, splits and then the bases are attracted to their pair (AT GC)
- Mistake in copy: mutation
- MEIOSIS
- Mutations
- Chromosome Mutations: change in chromosome number or structure
- Single-gene mutations: change in DNA structure within a particular gene
- Primeval Soup
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