WORD BANK beak size, competition, die, deep beaks, environment, evolution, food, genetic, greater, lesser, medium beaks, natural selection,

overproduce, shallow beaks, survive

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One trait that demonstrates the genetic

variation of finches of the Galapagos Islands is their

beaksize

This variation leads to some finches being better suited to their

For example, after the drought of 1977, finches with

were best suited to the

in the drier

were best-suited. Scientists know this

environment. In the very wet year of 1983, finches with

frequency of finches with the favorable

because in each sampled finch population there is a

in that the finches that are best-suited to their environment survive

trait. This demonstrates

as more

and reproduce, whereas ill-suited finches do not. Finches, like all organisms,

for limited resources.

individuals are born than the environment can support. This leads to

The Galapagos finch

Individuals with less favorable traits fail to reproduce and do not

or change over time, is a consequence of all these factors.

population demonstrates that

One trait that demonstrates the genetic variation of finches of the Galapagos Islands is their beaksize. This variation leads to some finches being better suited to their environment. For example, after the drought of 1977, finches with shallow beaks were best suited to the environment in the drier environment. In the very wet year of 1983, finches with deep beaks were best-suited. Scientists know this because in each sampled finch population there is a greater frequency of finches with the favorable trait. This demonstrates natural selection in that the finches that are best-suited to their environment survive and reproduce, whereas ill-suited finches do not. Finches, like all organisms, overproduce as more individuals are born than the environment can support. This leads to competition for limited resources.

Individuals with less favorable traits fail to reproduce and do not survive.

The Galapagos finch population demonstrates that evolution occurs or changes over time, as a consequence of all these factors.

What are finches?

Finches are small to medium-sized passerine birds belonging to the family Fringillidae, which is part of the order Passeriformes. They are known for their small, conical-shaped bills (beaks) adapted for eating seeds and sometimes insects or fruits. Finches are characterized by their robust bodies, short wings, and usually, a strong, often conical beak.