BIOL 1202 Chapter : Chapter 22 Notes
Descent with Modification: A Darwinian View of Life (Chapter 22)
What is evolution & Adaption?
Evolution has two main ideas
1. Change over time of the genetic composition of a population
2. Decent of modern organisms with modification from
preexisting organisms
a. Common ancestry
b. See these common traits today
Evolutionary adaption
-accumulation of inherited characteristics that enhance organisms ability
to survive in specific environments
-traits help organisms survive and reproduce better than other organisms in
population, and increase the frequency of those traits over time
-interactions with other organisms
Pre-Darwinian Theory of Evolution
Lamarck
Use & Disuse
-bodies of living organisms are modified through the use or disuse
of parts
Ex: How giraffes got long necks. Early giraffes had shorter legs
and necks and because of environmental challenges (trees) giraffes had to stretch
for food, which leads to longer necks over time
Inheritance of acquired characteristics
-these characteristics are passed to your offspring
-modifications are inherited by offspring
These ideas turned out to be WRONG
-What is in your genes determines what traits will be passed on
Evolution by Natural Selection
Darwin and Wallace developed the theory independently (Natural Selection)
Document Summary
Descent with modification: a darwinian view of life (chapter 22) Evolution has two main ideas: change over time of the genetic composition of a population, decent of modern organisms with modification from preexisting organisms, common ancestry, see these common traits today. Accumulation of inherited characteristics that enhance organisms ability. Traits help organisms survive and reproduce better than other organisms in. Interactions with other organisms to survive in specific environments population, and increase the frequency of those traits over time. Use & disuse of parts and necks and because of environmental challenges (trees) giraffes had to stretch for food, which leads to longer necks over time. Darwin and wallace developed the theory independently (natural selection) Bodies of living organisms are modified through the use or disuse. What is in your genes determines what traits will be passed on. Worked with birds, butterflies, etc. developed idea of how organisms. 5 year cruise along coast of south america and darwin was to collect.
