Bio 123: PP2 Material Flashcards
(37 cards)
What is the Biological Species Concept?
It states that two organisms are conspecific to one another if individuals of the opposite sex and mate and produce fertile and viable offspring.
Define Viable
Offspring must also be able to reproduce.
What is a weakness of the Biological species concept?
This concept cannot be applies to most species because most species do not reproduce sexual. Most species are asexual.
Define Evolution
Changes in the form and behavior of organisms throughout time. Species with a short lifespan can evolve faster and will have shorter evolution periods.
What is the Morphological/Typological species concept?
It separates species by their physical physical features and the number of certain characteristics that are shared between species.
What is the genetics species concept?
This is more useful for organisms that produce asexually. It categorizes species by similarities in DNA. Species under this concept are conspecific if they have 99% of the same genetic code.
Define Microevolution
The study of changes in allele frequencies of a population over time. Happens relatively faster and in smaller populations.
What is an allele?
A form on a gene
Define Macroevolution
The changes of an organism on a species scale
What is a phenotype?
The physical appearances of an organism.
What is a genotype?
The genetic code of an organism.
Define Creationism
All species were put on the earth by a higher being. This was the main belief before Darwin.
Who was Georges Cuvier?
- Cuvier was the first to acknowledge extinction but not evolution.
- He had a half science and half religious belief
- Argued that the species we have on the planet today survived a catastrophic event.
Who was Jean Lamarck
- Argued that throughout time, species change due to environmental pressures.
-Inheritance of acquired characteristics driven by need
What did Darwin want to prove?
-Wanted to prove that all species come from a common ancestor and that species change through time. Modification through decent.
What is Biogeography?
The study of patterns in the geographical distribution of species. This also gives us evidence of species having a common ancestor. If the environment changes then the organism must change with it.
Endemic
Species that only live in one biogeographic location
Rhea
Live in South America, look like ostriches
Define Fossils
Preserved remains/impressions of once-living organisms
Most are bones, teeth, shells, seeds, spores, and other parts
Fossils are found in sedimentary rock layers
What are some weaknesses of fossils?
Organisms have to be at the right place at the right time and must have hard bones in order to become fossils. Meaning that soft bodied organisms are missing from the fossil record. Scientists must actually find these fossils which could be difficult and costly.
What is the law of superposition?
States that younger rocks are found on the top layer and older rocks are found at the bottom.
Define Stratigraphy
The order relative position of sedimentary rock layers (strata) and its relationship to the geological time scale.
How did Darwin use fossils and the law of superposition to help prove his theory.
Darwin used the law of superposition and relative dating to show that there had been evolutionary change in species throughout time. He used this through the fossils that he found that showed similar anatomical appearances in species.
Who was Thomas Malthus?
Studied demography - characteristics that make up the human population.
- Gave Darwin the idea of competition
- Saw that as populations increase, competition increases
-Argues that a population cannot grow forever
-Argued that the environment is never stagnant
