Question

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The classical model of speciation specifies three stages. Which of the following correctly orders those stages, beginning with the first and ending with the last?

a) Divergence, physical or ecological isolation, reproductive isolation

b) divergence, reproductive isolation, physical or ecological isolation

c) reproductive isolation, physical or ecological isolation, divergence

d) physical or ecological isolation, divergence, reproductive isolation

The majority of genetic evidence accumulated to date supports the African replacement model for the origin of Homo sapiens.

a) True

b) False

The wide pelvis of Australopithecus sediba was likely the result of selective pressure for larger brain and skull sizes of offspring.

a) True

b) False

Which of the following helps to explain the current distribution of ratite (flightless) birds?
a) dispersal

b) all of the above help explain this distribution

c) geographic isolation

d) population bottlenecks

e) the founder effect

Answer 1

(a) Divergence, physical or ecological isolation, reproductive isolation.

intial step of specoation is barrier formation then ecological isolation between populations at the last step selection for increased reproductive isolation.

(b) False

It not just that the majority of genetic evidance accumulated to date supports the affrican replacement model for the origin of homo sapiens because affrican repalcement model is still spare and poorly dated, it is not exactly some of exceptions is sequentially decrease and invisible.

(b) False

The wide pelvis of australopithecus sediba was natural selection and genetic drift result small brain and large molar homo like trait.

(b) all the above help explain this distribution