Test 1 Flashcards

Question

Sexual Selection

Answer 1

Involves competition between males for mates, and the choices females make for mates. Male and female species usually look quite different, and this is called sexual dimorphism. Eg.) Males use combat (antlers) or visual displays (colorful feathers)

Answer 2

Introduce new alleles and variation into a population. The more genetic variation, the greater chance of a selective advantage in a changing environment. Gene flow: Is the movement of alleles from one population to another through migration. Eg.) Zebra mussels moving to lakes

Answer 3

Occurs when the allele frequencies in a group of migrating individuals are, by chance, not the same as that of their population of origin. This occurs more frequently on islands cause of the small population. Eg.) Amish community in a part of Pennsylvania with very high rates of polydactylism

Answer 4

Favours individuals with common phenotypes, and selects against those with extreme phenotypes

Answer 5

Favours individuals with rare phenotypes, selects against common phenotypes

Answer 6

Leads to the formation of distinct subpopulations of organisms. Allele frequencies may mean that 2 groups can no longer interbreed.

Answer 7

Humans ensure individuals with more desirable traits are allowed to reproduce. Humans pick which genes are passed down to the next generation. – Example of non-random mating

Answer 8

- By definition, evolution is a theory because there are tons of embryological, morphological, & biochemical evidence that demonstrated modern organisms evolved from older ancestral organisms and species today are continuing to change over time. - theories are supported by larger bodies of evidence and experimentation theories are never proven into laws - Laws are generalizations of patterns that occur repeatedly and predictably in nature

Answer 9

- In 1831 the Beagle set sail with Darwin when he was 22. The Beagle travelled to many destinations. Darwin found fossils of Glyptodonts and noted that they closely resolved the prospect day South American armadillo, and questioned if the armadillo could have risen from the ancient Glyptodont. Darwin concluded that variations of different species uniquely adapt or specialize to their own island environments. He collected 13 different species of finches and realised that they were exclusively found on the Galapagos Islands. He learnt that the reason why the island had such a diversity of finches, was because each finch adapts to gathering certain types of foods based on the size and shape of their beaks.

Answer 10

- Alfred Russell Wallace o He had similar ideas to Darwin based on observations in Indonesia o He sent Darwin a paper to review and so then Darwin released his theory

Answer 11

- Organisms produce more offspring than can survive, which leads to competition - Variation is evident in populations & this is passed down to offspring - Individuals suited to the environment survive to produce more offspring - Change is slow and gradual

Answer 12

- The Galapagos Islands were so unique in terms of speciation because the islands supported very FEW species but each was highly diverse. And they closely resembled species from the West Coast and South America. These species interested him because he began to question whether or not they could change over time.

Answer 13

- Black pepper moths o They were originally white, which camouflaged them against the light-colored trees. But due to pollution during the industrial revolution, the trees where they rested became blackened by spoot and they stood out and due to predation they adapted and became dark.

Answer 14

- There are several factors that can increase or decrease allele frequencies in a population such as mutations, gene flow, natural selection.. etc.