BIOL 226 Lecture Notes - Lecture 1: Carl Linnaeus, Vestigiality, Introduced Species
3 May 2018
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Biol 226- Chapter 22
Descent with Modification: A Darwinian View of Life
Definition of evolution
Descent with modification
Change in genetic composition of a population from generation to generation
Process of evolution: mechanism that produces the pattern of natural causes of the natural
phenomena observed and it’s the thing we are testing
Purpose of evolution is a unify theory that explains and connect a vast observation about living world
What is a scientific theory? Untested speculation.
Hypothesis (scientific term for theory): supported by evidence and hasn’t been contradicted by
anyone
Scala Naturae (ladder of life)
life forms could be arranged on a ladder of increasing complexity and are fixed and have a specific
place on the ladder
Aristotle point of view
species are fixed
Linnaeus
Classify life diversity
Binomial format of naming species
Cuvier
The older the stratum the more dissimilar fossils were to current life forms
From one layer to other species appeared and disappeared
Hutton
Earth’s geologic features could be explained by gradual mechanisms such as valleys being formed by
rivers
Lyell
Some geologic processes are operating today as in the past and at same rate
Lamarck
Found several Lines of descent from older to younger leading to a currently living
Mechanisms for evolution:
I Use and disuse of a body part lead to getting stronger or deteriorate
II Inheritance of acquired characteristic: organism could pass these modifications to next generation
(Darwin agreed)
Problem with Lamarck’s theory
o Single individual cannot evolve
o Cannot pass on acquired traits
Adaptation
inherited characteristic of an organism that enhance their survival and reproductively in a specific
environment of morphological or physiological and behavioral trait that maintenances or increases
the fitness (reproductive success) of an organism.
Malthus:
Human suffering (disease, famine, war) is a result of the faster growth of human population to the
food resource
Document Summary
Descent with modification: a darwinian view of life. Change in genetic composition of a population from generation to generation. Process of evolution: mechanism that produces the pattern of natural causes of the natural phenomena observed and it"s the thing we are testing. Purpose of evolution is a unify theory that explains and connect a vast observation about living world. Hypothesis (cid:523)scientific term for theory(cid:524): supported by evidence and hasn"t been contradicted by anyone. Life forms could be arranged on a ladder of increasing complexity and are fixed and have a specific place on the ladder. The older the stratum the more dissimilar fossils were to current life forms. From one layer to other species appeared and disappeared. Earth"s geologic features could be explained by gradual mechanisms such as valleys being formed by rivers. Some geologic processes are operating today as in the past and at same rate.
