Evolution and phylogeny

SL22018

3 domains of life

• bacteria

• archea

• eukarya

Non adaptive evolution

• genetic drift

• random mutations and random subsampling

• possibly advantageous, disadvantageous or neutral mutations

• despite advantageous chance may not select mutation so it goes extinct

• even a disadvantageou mutation might by chance be propagated

When was the origin of species published

1859

what 2 ideas did the origin present that were in conflict w the bible literalism

• the continuity of species- common ancestor, species going from one to another but not the process of it 

• evolution by natural selection- relationship between form and function

why wasnt the evolution by natural selection hypothesis accepted by 1900

• scientists didnt know how old the earth was and if it had enough time to evolve

• darwin emphasized artificial selection and how slow gradual effects can have major long term changes.

darwins estimate of how old the earth is

• darwin didnt know how old

• estimated with geologists for best guess

• 300 million years

thomsons estimate of age of earth

• knowing size and rate of heatloss from surface can calc age

• heat gradient known from mines- 50 feet deep = 1 degree hotter

• came up w estimate of around 20-40 million years

• he didnt know about radioactivity which threw off 

what is fishers fundamental theorem

rate of evolution = variance in fitness

why do cod mature faster and end up smaller

diesel engine powered fishing boats warming up water and fishing from the breeding grounds

jenkins objection to natural selection

• he theorised that blending inheritance was true and therefore no variation and no natural selection

• diluting beneficial trait and everyone ends up being the same

why does selection matter and inheritance dosent

because of mendelian inheritance

Types of selection

group selection- is the chance going to be good for the species

individual selection- is the change going to be goo dfor the individual

gene selection- is the change going to be good for the allele

RA fishers solution

1:! investment ratios are the stable solution from an individual point of view

even though the females put the most investment into next generation the males will have huge amount of offspring and therefore their genes get passed on

haplodiploid relationships

sisters are more related to eachother than they are to brothers

meiotic drive

• selfish genetic element

• ?????