10.3: Gene pools & speciation

Gene pool

The total of all the genes and the different possible alleles present in an interbreeding population.

Because of evolution, the frequency of alleles must change over time. Evolution = cumulative change in the heritable characteristics of a population over time.

Big Horn Sheep Qu. Pg. 456

Mass at birth/mortality DBQ

Speciation

Polyploidy

An organism that has more than two sets of homologous chromosomes. Caused by:1. Hybridization between different species

2. Cells prepared for meiosis (undergo interphase) but then meiosis does not occur, resulting in a diploid gamete. More common in plants than animals, can can lead to self pollinating plants. E.g. Allium genus (this group includes, onions, garlic, chives etc. all these species reproduce asexually)

Some weird but useful videos…https://www.youtube.com/watch?v=Q2vsG77PZ80 - funny and

short, clearly illustrates the main idea

https://www.youtube.com/watch?v=8yvEDqrc3XE - detailed example for evolution of birds of paradise. Very good examples. 10 mins.

https://www.youtube.com/watch?v=T1_vnsdgxII - extremely weird but fairly entertaining! Watch in your own time. 10 mins.

Gene poolhttp://sciencenetlinks.com/media/filer/2011/10/

07/evolution.swf

Nowhere to hide animation

Examplehttp://news.bbc.co.uk/2/hi/uk_news/wales/mid_/

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