Evolution Flashcards
What did Darwin propose in “On the Origin of Species by Means of Natural Selection”?
That over 1000s of millions of years, species arose from other, pre-existing species by a process of “descent with modification” or evolution. A key role in the development of the theory of evolution was that existing species have evolved from pre-existing species.
What were ideas on the origin of life largely influenced by for many years?
They were strongly influenced by religion and philosophy, and that a supernatural being created each type of organism individually at the beginning of time and that all modern organisms are unchanged descendants of those ancestors (fixity of species).
What did Plato contribute to evolution?
His philosophy was the fixity of species, and that there may be small variation occurring between individuals but the species itself remained unchanged. These variations were imperfections.
What was Aristotle’s contribution to evolution?
He viewed species as fixed, but his observations led him to conclude that life forms could be arranged on a ladder of increasing complexity.
What was Baron Georges Cuvier’s contribution to evolution?
He was the first to use comparative anatomy to develop a system to classify animals. He founded the study of paleontology, and proposed that the earth was only 6,000 years old.
When and what problems arose to the idea of the fixity of species?
In the late 18th and early 19th centuries, discoveries by European Explorers challenged conventional ideas of the fixity of species. They found more diverse organisms, including unique fauna, flora, and fossils. Fossils showing the different layers of different organisms that were not distributed randomly but seemingly sequentially were troubling.
Who was Eramus Darwin?
Late 18th century, believed in evolution because he was aware that modern species were different from fossil types and saw how plant and animal breeders used breeding practices to change the traits of domestic species- but he did not know what caused evolution.
What did BG Cuvier propose about fossils?
That abrupt changes in fossil record came about due to catastrophes - aka extinctions occurred because of great floods and the like. Catastrophism.
Who was Jean Baptise Lamarck?
A zoologist who saw the first evidence of fossil in a different light than Cuvier. He though fossil evidence was evidence of gradual change (true evolution), noting that the simplest organisms were at the bottom and the more complex at the top. He provided groundwork for evolutionary theory by showing some of the intimate relationship between variation and evolution.
What was Lamarck’s theory of Inheritance of Acquired Characteristics?
His proposal that organisms acquired characteristics during their lifetime and then passed them on to offspring (Giraffe neck).
What is an adaptation?
A biological adaptation is an anatomical structure, physiological process, or behavioral trait of an organism that increases the expected long-term reproductive success of the organism.
What were Darwin’s observations and thoughts?
- Could two animals in different regions have originated from the same ancestor?
- Species varied slightly from place to place - variation is the key to understanding how species change
- Adaptations for eating different foods
What is Uniformantarianism?
Proposed by James Hutton and promoted by Charles Lyell, “the past is the key to the present”. Laws of physics and chemistry remain the same, so natural processes which acted in the past will continue to act. Slow geological processes to substantially change the earth’s characteristics take a long time, so the earth had to be very old. This influenced Charles.
What book by Charles Lyell influenced Darwin?
Principles of Geology.
What is an evolutionary tree?
A drawing that shows the most ancient forms at the bottom and their descendants branching off irregularly along the trunk.
