evolution by natural selection Flashcards
Lecture 1 - Mark Briffa
Catastrophism
the earth has been shaped by catastrophic events that also cause extinctions
evolution by ‘transformation’
Lamarck
- species never become extinct
- over time they become new species
- offspring inherit characters aquired by their parents
the ‘struggle for survival’
- individuals with advantageous variaions would do better in the struggle for survival
- these individuals would produce more offspring
‘descent with modification’
-offspring share some of their parents features
- advantageous variations would automaticallly increase in the populaton between generations
- lineages would change over time - different from ancestors
- organisms well suited or ‘aapted’ for their environment
a continous process with no ‘end point’
Darwins theory
- evolution like ‘bush’ not a ‘ladder’
- ‘common descent’ of species
- explains evolution and adaptaion
Neo-Darwin synthesis
(or the modern synthesis)
- advantageous variations inherited genetically
- recombination and mutation provides the variation for selection to work on
maladaptive
having a inadequate adaptation
does more harm than help
(remember mal = bad in spanish ‘bad’ adaptation)
natural selection
“the different reproductive sucsess of different phenotypes”
adaptation
a trait that enables an orgnism to survive and reproduce better than if it lacked the trait
fitness
quantitative representation of individual reproductive success