Week 8 Flashcards
What is the sum of natural selection and evolution?
Differential survival and differential reproduction.
Genetic variability and natural selection.
What was Lamarck’s theory in relation to evolution?
Changes occur within a lifetime and are passed onto offspring.
What discovery did Charles Darwin make in the Galapagos Islands in relation to tortoises?
Each island had either long or short necked tortoises depending on the island’s vegetation.
What did both Alfred Russell Wallace and Charles Darwin conclude?
Life forms arose by decent from a common ancestor, and that natural selection is the mechanism by which species change and new species arise.
What are the four basic premises of Darwin’s theory?
1 - World’s animals and plant communities change over time.
2 - New species arise through slow and steady environmental changes.
3 - All organisms descend from an original common ancestor, over time, the process of natural selection created different species.
4 - Natural selection also acts to maintain the status quo.
Why do some survive/reproduce and some not?
Predation, competition for resources; mates, food, nesting sites, roosting sites.
What has changed about the title “the Theory of Evolution”?
No longer a theory; we can observe it in real-time.
What are the different forms of convergent evidence?
Fossil - dating of fossils shows a timeline of change in structure.
Biological - Species from Australia, which has been isolated for long time, have different survival features.
Anatomical - vertebrate forelimbs contain the same set of bones organised in similar ways.
Embryological - organisms that show similarities in their embryonic development may have a common ancestry.
What did Gregor Mendel discover?
Laws of inheritance; did selective breeding with plants. Discovered the 3:1 ration in the f2 generation; there is an order to inheritance.
What are chromosomes and genes?
Chromosomes like a library; genes are like a book within that library. Chromosomes located in nucleus of each cell (neuron).
What are chromosomes made up of?
DNA
What is located within DNA?
Base pairs which are the coding of amino acids (proteins).
What is the process of mitosis?
Cell division; 1 chromosome (2N) -> 2 chromosomes (2 x 2N).
What is the process of meiosis?
Sex cell formation; 2N (diploid) to 4 x 1N (haploid) sex cells.
How do conditions like down syndrome occur?
The incorrect splitting of 2 x 1N cells. E.g. the process of splitting 2 x 1N cells into 4 x 1N cells does not work, results in 3 x 1N cells instead.
