Charles Darwin from 1859 until 1872 completely altered the biological understanding of life on earth.
Can the Origin of Species and Genesis be reconciled together in a new rendition of humanity's place in nature? Perhaps, maybe, yes, or no the inquiry must start with two related questions that are asked by the author:
• In what kind of world do we live?
• What is the evidence for evolution on Earth?
The Text
What Evolution Is, Ernst Mayr, 2001.
see: Understanding Evolution's web site at U. C. Berkeley.
Our natural place | Evidence | What does evolve? | Conclusions
i.What describes and defines humanity’s place in nature?
Human
origins
Creation -- occured in stages: an innate generative capacity or a deliberate design?
La Scala natura, or the great chain of being -- a sort of ladder of bodily forms.
Variety within the same breeds of domesticated animals and plants.
Common ancestry there are similar cellular structures shared by all life.
Fossils the remains of similar to and very divergent forms from current life.
Antiquity of the geological past is revealed in pollen, tree rings, chemistry.
Biological differentiation due to geographical isolation leads to speciation, and thus change in a population over generations.
The human family tree that grew out of Africa.
A matrix of possibilities emerge from these two possible ways to understand the world:
| A) fixed kinds (ideas) | B) change (flux) | |
1) Infinite duration
|
||
| 2) Constant
world of short duration |
||
|
Type
or essence |
Existence
& probability |
“Already in the 1860s knowledgeable biologists and geologists accepted that evolution was a fact, but Darwin’s explanations of the how and why of evolution faced protracted opposition, as we shall show in later chapters…. some of the evidence for the actual occurrence of evolution that has been gathered since 1859.”
p. 11
Our natural place | Evidence | What does evolve? | Conclusions
“the findings would make no sense in any other explanation."
A. Fossils
B. lineage and variability (15)
C. Common descent
chimpanzees
gorillas
D. Morphological similarity
E. Embryology -- there are certain developmental stages common to vertebrate embryos
F. Vestigial
structures -- the appendix, coccyx,
G. Biogeography or global distribution --
1. the existence of rhinoceros, camels and elephants in Asia and Africa.
2. Rheas, Ostriches, and Emus on different continents.
H. Molecular evidence or molecular biology --
The importance of molecular (DNA comparisons) analysis
The molecular clock
Evolution of the genotype as a whole
“the essentially complete DNA sequence of the entire genome”
p. 37
genes are defined "as base pair sequences"
Origins of new genes (38)
Orthologous and paralogous genes
Our natural place | Evidence | What does evolve? | Conclusions
iii. What does and what does not "evolve" over time?
Offspring vary
Variations accumulate at a deferential rate among many more offspring than can survive
Over time, the surviving reproductive populations vary too greatly to breed successfully
- a. jumping genes or transposons
- b. genetic drift
- c. geographical isolation
- d. behavioral isolation mechanisms
Our natural place | Evidence | What does evolve? | Conclusions
Conclusion:
The argument over Darwin's findings has removed some of the most imaginative and wonderfully bizarre qualities, in our perspective, of nature from the focus of our attention. Instead, we dwell on the exceptions to the rule, the dry to bland details of acquiring a living, and the hard to answer questions when all around us the exceptions, wonderment, and an enormously deep and certain knowledge calls out for our attention.
Darwinism | Ernst Mayr | Consequences of Darwin's Revolutions
Class related web pages
The Complete works of Darwin on the Internet
Notes from the Origin of Species.
Related pages Darwin's Revolution | primary sources | plate tectonics
Terms | Glossary | Word webs | Basic vocabulary | Advanced Vocabulary | Antonyms | Synonyms
Writing | Interviews | Free Writing
