Flashcards in Chapter 1.4 Deck (12)
Why was Charles Darwin considered a scientific Pioneer?
with the publication of "The Origin of Species by Means Of Natural Selection" (1859)
- He established a scientific way of thinking
- He replaced superstition with natural laws
- Explained the duality of unity and diversity
What were the two main points outlined in "The Origin of Species"
1. Species showed evidence of "decent with modification" from common ancestors
2. Natural Selection is the mechanism behind "descent with modification"
List some of Darwin's Observations outlined in "The Origin of Species"
- Individuals in a population vary in their traits, many of which are heritable.
- More offspring are produced than survive, and competition is inevitable.
-Species generally suit their environment
What did Darwin Infer from his observations?
- Individuals that are best suited to their environment are more likely to survive and reproduce
- Over time, more individuals in a population will have advantageous traits
Define Natural Selection
Evolution occurs as the unequal reproductive success of individuals I.E. The environment "selects" for the propagation of beneficial traits.
Some individuals within a species have hereditary advantage over their competitors
Ex: better camouflage, disease resistance, ability to attract mates, as result they produce more offspring and advantage is passed on
Give an example of "Unity in diversity" arising from "Descent with modification"
The forelimb of the bat, human and horse and the whale flipper all share a common skeletal architecture
Example also found in fossils providing evidence for anatomical unity from descent with modification
Give an example of Natural selection causing ancestral species to give rise to two or more descendent species
The Finch species of the Galapagos islands are descended from a common ancestor.
Evolutionary relationships are often illustrated with treelike diagrams that show ancestors and their descendants
Which publication of Charles Darwin described Human Origins and adaptations?
"The Descent Of Man" (1871)
Change in genetic composition of population of organisms
ex: development of bacterial resistance to antibiotics
ex: appearance of new strains of AIDS virus
Define Selection Pressures
Natural forces that promote the reproductive success of some individuals more than others
Features of an organism's anatomy, physiology or behavior that have evolved in response to these selection pressures and enable the organism to cope with the challenges of its environment