Question

Darwin observed that the finches on two different islands in the Galapagos belonged to the same family, but showed a lot of variations in their beak size and shape. How can this variation be justified?
will medal and fan

Answer 1

@imqwerty

Answer 2

migration to an environment different from their birthplace, and adaptation to the available food, ultimately leading to speciation

Answer 3

migration to the same environment as their birthplace, and sudden mutation, ultimately leading to formation of different races

Answer 4

migration from their original birthplace to a different environment, and modification of the habitat according to their specific need, ultimately leading to speciation

Answer 5

@spoodie18

Answer 6

@dan815

Answer 7

@16dsanders

Answer 8

@BRONCOBURDEN17

Answer 9

Their beak size was different because of the different foods that they ate on the different islands. The environment which they were in, selected (through natural selection) for a particular shaped beak.

Answer 10

thx

Answer 11

can u help me with a couple more

Answer 12

What is the role of natural selection in evolution?

Answer 13

Natural selection is a specific mechanism of evolution in which the heritable traits (characteristics) help an organism to survive his generation.

Answer 14

Natural selection is a specific mechanism of evolution in which the heritable traits (characteristics) help an organism to survive and reproduce successfully

Answer 15

Natural selection is a specific mechanism of evolution in which all acquired traits (characteristics) help an organism to survive and reproduce successfully.

Answer 16

To evaluate properly a role of natural selection, its effect should be considered in relation to different phases of the evolutionary cycle postulated earlier by the author. At the first stage of the cycle natural selection is directed towards organism's persistence to detrimental external factors and leads to an increased fitness (that is viability and fecundity) in every generation. At the next stage of the cycle natural selection occurs under conditions of intraspecific competition and is directed towards a more efficient utilization of food resources. At this stage natural selection leads to formation and divergence of intraspecific races and is carried out by "single" selection actions occurring now and then and consisting of the survival of rare mutants with an altered ecological potential. Such a strict selection for certain mutants occurs again during the periods of acute competition for food, the selected mutants being characterized by a decrease of fitness, the latter to have been restored by means of the "ordinary" selection within the intervals between crises. According to the model suggested, homozygotes for "detrimental" recessive alleles could be selected in diploids, as the mutants mentioned with altered ecological potential. At the end of the cycle, there is a kind of selection for hybrids in which ecological potential of specialized intraspecific races is combined. The genetic drift is considered as an inevitable consequence of the postulated mechanism of natural selection.

Answer 17

thx