Anthro week 2 flashcards
Define scientific method
Has principles,methods and ways of evaluating explanations
Often invloves expiriments and the results must be repeatbale by others
Emperical definition
based on measurnments, observations and analyses
Theory def
Extreamly well supported idea (data, observation ect) that has not been disproven
Intended to explain something
Hypothesis def
A possible explanation for a phenomenon that may be tested by scientific methods
-A starting point for further explanation
4 primary stages of scientific method:
1-Develop a hypothesis to explain phenomenon or answer a question
2-Test the hyopthesis by collecting and analyzing data
3)Accept, reject or modify your hypothesis based on collected data
4)Continual re-evaluation of hypothesis based on new data
Pseudoscience def
statements or practices that claim to be scientific and factual but in fact do not follow the scientific method
History of evolution before Darwin:
-Understanding the world was based on the creation narrative (judism and christianity)-world was created by God in 7 days
-World was seen as fixed and unchanging
-Essentialism
Existed a perfect "ideal" world and an imperfect "physical world'
Plato believed...
All things that share the same essence belong to the same natural kind
The Great Chain of Being:
Adaptation of the ideas of the greek philisopher "aristotle" by medieval thinkers
Aristotle suggested that different kinds of organisms could be arranged in a single line
Attributes of organisms close to one another would always overlap to some extent
Idea of fullness
There are no gaps in the world of organisms created by God
Meant that differnent kinds of organisms could be arranged in a single heiarchy (or chain) based on the degree to which the depart from the divine ideal
Degree of difference = Degree of excellence
Catastrophism:
-Princple of continunity between all beings was critcized by George Cuvier (french scientist)
-He believed based on anatomical reserch there were 4 catagories of living things
-Study of fossils led him to believe that some species had been abruptly wiped out and replaced by new species
-Caused lots of debates and significantly weakened the concept of "The Great Chain of Being"
4 catagories of living things (catastrophism- Gerorge Cuvier)
1- Vertebrates (humans)
2-Arthropods (Spiders, crabs, insects)
3-Molluscs
4-Radiata (starfish)
John Ray
Developed the concept of genus and species
Carolus Linnaeus
Added taxta of order and class to the classification system and included humans and put them in the same category as apes/monkeys
George-Louis Leclerc de Buffon
Noticed that change within a species could effect the environmemt in which it lived
Belived that people should seek explanations outside of religion
Jean Baptiste Lamarck
Contributed to the development of "The theory of the inheritance of acquired characteristics" Example giraffes necks
James Ussher
calculated that the earth was created on OCTOBER 22 4004 BC based on historical writings and the bible
James Hutton
Suggested that the earth was under constant formation
Imperceptible events vs catastrophes
Theory of Uniformitarianism
geological forces at work in the present day are the same forces as the past---- meant that the earth was wayyyyy older than 4004 BC
Charles Lyell
popularized the theory of Uniformitarianism and pushed back the age of earth to 100,000 years old
Charles Darwin
Was inspired by Thomas robert Malthus and Alfred Wallace
Gregor Mendel
Undertook a comprehensive program of breading pea plants to undertsand how inheritance works
He spent years cross breading and counting the occurance of the various traits in each plant
When plants with opposing traits were crossed, only 1 of the traits showed in the offspring
The trait that disappeared always appeared again in a 3:1 ratio
Gergor Mendel established a very basic understanding of genetics
Genes, alleles, dominant and recessive alleles and the differneces between a geonotyoe and phenotype
Mutation def
Errors in the replication of DNA can be neautral, beneficial or harmful
Source of variation within populations
Genetic drift def
when changes in allele frequency occurs by chance
Gene flow def
When genes move between populations that are members of the same species but that do not normally mate with one another
Adaptative Radiation def
when species rapididly adapt to an ecological niche, often expanding its population and diversifying into multiple species
Sexual selection def
The selection of a partner/mate of the opposite sex and the competition between members of the same sex to acsess members of the opposite sex for reproduction
-Based on physical traits
Gradualism def
slow, steady change with a new species eventually emerging
Punctuated equillibrium def
slow, steady change occasionally intererupted by short peroids of significant change
Speciation def
the process by which species emerge
happens in multiple ways