https://padlet.com/WoonKeat/l2powco2nato Descent with modification through natural selection en-us 2017-05-15 09:16:08 UTC 2026-03-04 11:57:22 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Pictureland.png https://padlet.com/WoonKeat/l2powco2nato/wish/171980956 The curve shows normal distribution which indicates continuous variation. There may be multiple genes that code for the beak size. After long periods of drought, there are larger harder seeds that exert selection pressure. Finches with larger beak size have selective advantage ]]> 2017-05-16 01:32:02 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171980956 https://padlet.com/WoonKeat/l2powco2nato/wish/171981027 The selection pressure is the availability of food. Stabilising selection has occured for both curves and the extremes are eliminated. For the curve following the long period of drought, finches with beak sizes between large and medium are most suitable for picking up and eatinglarger and harder seeds. For the curve following long period of wet weather, finches with medium beak sizes are most suitable for picking up smaller and softer seeds ]]> 2017-05-16 01:32:46 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171981027 https://padlet.com/WoonKeat/l2powco2nato/wish/171981039 3aiii 
stabilizing selection 
Intermediate favoured while extreme phenotypes are selected against 
Normal distribution 

4b. Distinct phenotypic differences between the populations of D.paradiseus may have arisen due to natural selection. Initially, racket tailed drongos may all have only one type of crest shape.as the drongos migrate to different countries they become geigraphically isolated

Subjected to different selection pressures

Mutations, crossing over and independent assortment of homologous chromosomes during meiosis, formation of game tester, random fusion of gametes during sexual reproduction, changes in allele frequency, different phenotypes



]]> 2017-05-16 01:33:00 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171981039 https://padlet.com/WoonKeat/l2powco2nato/wish/171981136 Continuous variation: there are multiple genes that code for and control beak sizes. They influence beak sizes in an additive manner, causing the shape of the graph to be as shown. Environmental factors like weather will act as a selection pressure.]]> 2017-05-16 01:34:23 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171981136 https://padlet.com/WoonKeat/l2powco2nato/wish/171981627 Was actually correct 2/3 ]]> 2017-05-16 01:39:29 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171981627 https://padlet.com/WoonKeat/l2powco2nato/wish/171982751 Genetic variation 
Natural selection
Closer to equator -> higher temperature -> more bald 
Selection pressure is temperature 

Or maybe just founder effect]]> 2017-05-16 01:51:43 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171982751 https://padlet.com/WoonKeat/l2powco2nato/wish/171982752 - Genetic variation
- Migration of some birds to different parts of the land
- subjected to different selection pressures due to different environments such as difference in predators
- also, frequency of alleles due to founder effect --> change in allelic frequency]]> 2017-05-16 01:51:44 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171982752 https://padlet.com/WoonKeat/l2powco2nato/wish/171982755 Genetic variation 
Natural selection 
- Different selection pressures in different parts of Southern Asia 
- different phenotypes selected for ]]> 2017-05-16 01:51:45 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171982755 https://padlet.com/WoonKeat/l2powco2nato/wish/171982806 - There are genetic variations causing difference in crest length in the original population (mutation, meiosis ...)
- When the drongos fly over to a new island, have different environment and hence different selection pressure
- Individuals w a specific crest length selected for, thrive in that area (Natural selection)
- Got gene flow so no speciation]]> 2017-05-16 01:52:26 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171982806 https://padlet.com/WoonKeat/l2powco2nato/wish/171984913 1. Morphololgy
Homologous structures are derived from a recent common ancestor that reveal evolutionary relationships

2. DNA sequences
Multiple sequence alignment ]]> 2017-05-16 02:11:35 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171984913 https://padlet.com/WoonKeat/l2powco2nato/wish/171984969 Morphological data is used to identify homologous structures that may show how organisms are related. If no phenotypic difference, use molecular data to see how different they are based on the degree of homology of DNA sequences and amino acid sequences]]> 2017-05-16 02:12:04 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171984969 https://padlet.com/WoonKeat/l2powco2nato/wish/171984975 Organisms are grouped into taxa based on their shared characters — morphological or molecular homologies. Organisms are then further grouped into lower taxonomic ranks based on increasing similarities. ]]> 2017-05-16 02:12:08 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171984975 https://padlet.com/WoonKeat/l2powco2nato/wish/171985001 Morphological: homologous structures, vestigial parts, similarities reflect shared ancestry.
Molecular: determine degree of homology in primary sequence, similarities in DNA sequences ]]> 2017-05-16 02:12:21 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171985001 https://padlet.com/WoonKeat/l2powco2nato/wish/171985090 By analysing structural features, systemtists can identify homologous features which may be shared ancestral character or shared derived characters to determine evolutionary relationships such as recent common ancestors and distant common ancestors. By analysing molecular data, molecular homologies can be identified to clarify phylogeny. The greater the degree of homolgy, the more closely related the species are considered to to be and hence organisms can be classified. ]]> 2017-05-16 02:13:14 UTC https://padlet.com/WoonKeat/l2powco2nato/wish/171985090