101 - Molecules & Cells
Lecture 1 – Why are we here?
If you look close enough at any organism you just see chemistry and
molecules interacting.
Life follows the same rules
- what we call life arises out of chemical and physical complecity
o an emergent property
Viruses
- debate as to whether viruses are alive or not
- have to infect other cells to survive
- proteins surrounding DNA
Supernatural explanations are not science as they are not testable.
“The art of the soluble”
Art – creative aspect of science
Of the solube – must be able to come up with an explanation and test
Biologists have a mechanism
Evolution by NATURAL SELECTION
o Charles Darwin
o Not ‘spontaneous’ in the sense of ‘sudden’ but very SLOW and
GRADUAL
o No outside help
o Simple but extraordinarily powerful idea
o Gradual process that enhances the organisms’ ability to survive
and reproduce
Natural Selection
Organisms resemble their parents, but with random variation.
Normally, not all offspring can survive or reproduce – there is
competition.
Those that do reproduce are those that are best adapted to the current
environment.
It is a unifying theme as ‘nothing in biology makes sense except in the
light of evolution.’
Another problem with ‘spontaneously’
- The fight against disorder (entropy)
- Complexity of life seems incompatible with this principle
- Entropy – over time things get more disordered
- Living organisms maintain themselves in a highly complicated but
ordered state.
- How can living organisms maintain their order, when everything is
getting more disordered all the time?
Lecture 1 – Why are we here?
If you look close enough at any organism you just see chemistry and
molecules interacting.
Life follows the same rules
- what we call life arises out of chemical and physical complecity
o an emergent property
Viruses
- debate as to whether viruses are alive or not
- have to infect other cells to survive
- proteins surrounding DNA
Supernatural explanations are not science as they are not testable.
“The art of the soluble”
Art – creative aspect of science
Of the solube – must be able to come up with an explanation and test
Biologists have a mechanism
Evolution by NATURAL SELECTION
o Charles Darwin
o Not ‘spontaneous’ in the sense of ‘sudden’ but very SLOW and
GRADUAL
o No outside help
o Simple but extraordinarily powerful idea
o Gradual process that enhances the organisms’ ability to survive
and reproduce
Natural Selection
Organisms resemble their parents, but with random variation.
Normally, not all offspring can survive or reproduce – there is
competition.
Those that do reproduce are those that are best adapted to the current
environment.
It is a unifying theme as ‘nothing in biology makes sense except in the
light of evolution.’
Another problem with ‘spontaneously’
- The fight against disorder (entropy)
- Complexity of life seems incompatible with this principle
- Entropy – over time things get more disordered
- Living organisms maintain themselves in a highly complicated but
ordered state.
- How can living organisms maintain their order, when everything is
getting more disordered all the time?
