BIOL1003 Lecture Notes - Lecture 2: Staphylococcus Aureus, Melanism, Salmonidae
BIOL1003, Module 1: Evolution
Lecture 2 – Modern View of Evolution
• Modern view of evolution comes from Darwin, natural selection (plausible mechanism) as a
means for evolution
• By crossing animals with slightly differing characteristics, this can create large differences (this
can be done through artificial section). Causes an enormous diversity within a species
• Must start with variation within a population because otherwise change will not be generated
• Plants are easier to selectively breed, as you can breed it with itself
• Darwin was an evidence based scientist, had to have all the information before he was able to
draw a conclusion
Artificial Selection
• Species are not fixed in form
• Gradual, incremental changes can result
Darwin's Syllogism - observation
• If…
I. There is a variation within a population; and
• Variation is phenotype
• Variation in behaviour
• Genotypes
• DNA sequences
• chromosomes
II. Variation is heritable; and
• The variation we see is passed on
III. There is a struggle for existence; and
• Nature is full of hazards
• Not all offspring survive
• Even slow breeding things can reach massive numbers, if all offspring survive. But
the do’t, therefore ost hae a ostat uer
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Document Summary
Species are not fixed in form: gradual, incremental changes can result. There is a variation within a population; and: variation is phenotype, variation in behaviour, genotypes, dna sequences chromosomes. Variation is heritable; and: the variation we see is passed on. There is a struggle for existence; and: nature is full of hazards, not all offspring survive, even slow breeding things can reach massive numbers, if all offspring survive. But the(cid:455) do(cid:374)"t, therefore (cid:373)ost ha(cid:448)e a (cid:272)o(cid:374)sta(cid:374)t (cid:374)u(cid:373)(cid:271)er. If there weren"t things stopping golden staph, then by tomorrow, the world would be buried in 2m of golden staph. Some variants survive/ reproduce better than others: the(cid:374) . Natural selection must be occurring (no way around it: evolution is happening now, it happens constantly. If evolution through natural sele(cid:272)tio(cid:374) e(cid:454)plai(cid:374)s the ra(cid:374)ge of (cid:271)iodi(cid:448)ersit(cid:455) (cid:449)e see . There should be observable (and preferable reproducible) cases of microevolution: we should be able to reproduce microevolution selectively.
