Lecture 2 - History Of Evolutionary Theory Flashcards
What is Plato’s theory of forms?
Eidos or theory of forms
It describes ideal and imperfect worlds, contrasting perfect forms with imperfect manifestations.
What did Aristotle speculate off of Plato’s views?
He classified species in terms of complexity, envisioning a ladder increasing towards perfection.
What does Scala naturae refer to?
Greta Chain of being
It integrates Greek philosophy and Christian ideas, placing beings in order of perfection. Ie God at the top and kings next, etc.
Who was Al-Jahiz and what was his contribution?
A polymath who translated Aristotle and added the concepts of struggle for existence and the role of the environment
He believed in the fixity of species (as most philoshers did).
What major shift occurred during the scientific revolution?
Questioning the nature of the world and acceptance of species variation.
This was in early 17th century Europe.
What is taxonomy and who developed it?
Description of classification of life forms based on shared characteristics
Developed by Carolus Linnaeus.
What is the Systema naturae? Who developed it?
Involves placing species into an inclusive hierarchical system of Holotypes. These Holotypes include general to specific characterizations, ie kingdom, phylum, class, order, family, genus, and species. Carlos Linnaeus developed it.
What did Georges-Louis Leclerc – Comte de Buffon contribute to evolutionary thought?
Proposed a greater age of the earth and regional variation in plants and animals.
He believed environmental factors were agents of change.
What did Jean-Baptiste Lamarck speculate?
The inheritance of acquired characteristics, ie the use and disuse theory.
What theory is Georges Cuvier known for?
Catastrophism
He challenged the fixity of species by proposing that catastrophes wiped out entire species.
What did Charles Lyell contribute to the debate?
He created the theory of uniformitarianism. This explains that the geological processes that have shaped earth to be what it is today, are still at play.
What was Thomas Malthus’ view on population growth?
Populations can increase indefinitely without limits
If a population has fantastic living conditions, the population will increase, which causes competition among the pop.
What did Charles Darwin document during his voyage on the HMS Beagle?
Fossils bear similarities to living species and diversity in living forms
Observed significant variation in species, particularly finches in the Galápagos Islands.
What notable observations did Darwin make about finches?
Variation in beak sizes and resource specialization
Indicated that they were not in competition with each other.
What was the significance of Darwin’s Finches?
Darwin brought finches back with him from his travels. He studied their variation in beaks and therefore different specializations in certain resources. This meant each variation was not in competition with each other.
What are the 4 fundamentals of natural selection?
- Natural selection cannot occur without variation in inherited traits
- A trait must be heritable for selection to act on it
- Fitness is a relative measure that changes with the environment
- Natural selection can only act o traits that affect reproduction and the likelihood that organisms will produce offspring
Define natural selection.
Beneficial traits increase in frequency in a population over time due to the differential survival and therefore fitness of that population.
Define selective pressure.
The limited amount of resources in a given environment.
Define geographic isolation and how it can form new species.
Group becomes isolated, they adapt to their different environment, that group of a species evolves while the others of that species stays the same.
