The synthesis of evolution, maths and genetics post Darwin

1859

• 
  The publication of on the origins of species 

• Represents the single biggest transition in our understanding of evolution and of life and human history 

• By understanding where Darwin was both right and wrong, you should be able to develop a robust understanding of the process of evolution 

• The origin presented two ideas that were in conflict with biblical literalism 

  • The continuity of species  

  • Evolution by natural selection 

• The origin was a rush job 

  • Triggered by the letter from Alfred Russel Wallace in 1858 

  • Originally intended as a massive book 

  • It is unusual as it is his idea, so no references 

  • Intended as a popular book 

what were the prior ideas

• 
  Almost every culture has a different story 

• In protestant England the dominant notion was biblical literalism 

  • Genesis 

  • Created in 6 24hr days 

• Warm-blooded animals arose from a single common ancestor 

• Organisms pass on physical traits acquired during their lifetime (such as a giraffe's neck stretching) to their offspring 

natural selection was understood before Darwin

• 
  James Hutton (Investigation of the Principles of Knowledge (1794)) 

  • Lays out a clear argument for a process of change by natural selection, and does so through analogy with the process of artificial selection 

• Patrick Matthew (Naval Timber and Arboriculture (1831)) 

  • Ideas on the mechanism of evolutionary change appeared as a brief note in the appendix 

  • Bears a strong resemblance to evolution by natural selection 

the reception of the origin

• 
  The religious for the most part objected 

• By 1900, continuity of species was more or less accepted in academic circles as a viable hypothesis 

  • Darwin spent considerable effort in his later years adding further support – even regards how we express emotions 

  • Hairs on the back of the neck stand up like a dog's hackles (same muscles) 

  • Blind babies express emotions like anyone else (must be genetic) 

• However, Darwin did not get everything right 

  • Evolution by natural selection was not broadly accepted as the correct hypothesis 

why was evolution by natural selection not accepted

• Too many questions 

• Main one was : was there enough time? 

• How old is the earth 

• Is natural selection too slow and gradual to be directly witnessed 

• Darwin emphasised artificial selection and how slow gradual effects can have major long term changes 

• Now more questions are being asked 

  • e.g. was natural selection compatible with knowledge about inheritance