BIOLOGY 1M03 Lecture Notes - Lecture 3: Naked Mole-Rat, Ancient Dna, Melanism
8 Feb 2017
School
Department
Course
Professor
Document Summary
Extinct species, fossils, ancient dna, vestigial traits, transitional forms, observed examples of speciation. Hypothesis: giraffes have long necks to provide access to food resources. Prediction: giraffes should eat food that are high in trees. Observation: more often than not, not stretching their necks and eat food quite low in height. More bites at mid-range height (60% of their height) Alternative hypothesis: (that isn"t really mutually exclusive from the feeding hypothesis) Evolved long necks because longer-necked males win more fights than shorter-necked giraffes, and can then father more offspring by winning over the female. Increase in allele frequency of long necks in population. To see if female is ready for mating, she urinates in male"s mouth and male determines if she"s ready, once she"s ready, males fight. Study of giraffes can inform our understanding of extinct species. Brontisaurus might have long neck for being best fighter as well.
