Question

A common means of sympatric speciation is:
A.Polyploidy
B.imposition of geographic barrier
C.spatial segregation of mating lines
D.temporal segregation of breeding seasons

Answer 1

Hint: Speciation is the development of a new species through a variety of factors. The Rate of speciation depends on generation time, environmental conditions, etc. speciation can be caused by a change in just one gene or a set of genes causing some sort of isolation.

Complete answer:
Types of speciation are allopatric speciation, parapatric speciation, sympatric speciation, peripatric speciation.

Allopatric speciation happens in geographically isolated population, separation due to different geographical events. Parapatric speciation happens when part of a population goes into a new habitat bordering the range of the parent species. Some gene flows may occur between populations in the border zone. Peripatric speciation is a small subset of a large population that becomes isolated at the periphery of the original population range.

Sympatric speciation: it happens in populations that live in the same geographic area. It is less common than allopatric speciation. It happens when gene flow is diminished by polyploidy, habitat differentiation, sexual selection. Speciation happens mostly in polyploidy. Polyploidy is an offspring or group of offspring will be generated with two times of chromosomes, where a normal individual has two copies of each chromosome (diploidy), these offspring may have four copies (tetraploidy). Tetraploid individuals cannot mate with diploid individuals, producing reproductive isolation.

Hence the correct answer is OPTION(A)

Note: Species is the smallest evolutionary independent unit. Different species follow different evolutionary trajectories. The essence of speciation is shortage of gene flow. Allopatric (allo- different, patric- homeland). Sympatric (sym- same, patric- homeland). Concepts of species can differentiate in morphological, biological, modern.