intergradation

[ in-ter-grey-dey-shuhn ]

noun

1. the act or process of intergrading or the state of being intergraded.
2. an evolutionary process by which different species of organisms tend to merge through a series of intermediate stages or grades.

Other Words From

• inter·gra·dation·al adjective

Word History and Origins

Origin of intergradation¹

First recorded in 1870–75; inter- + gradation

Example Sentences

The small size suggests intergradation between the subspecies collinus and eremicoides.

From Project Gutenberg

This difference in color suggests intergradation at this place between C. l. microdon that ranged to the northeast, C. l. cagottis to the south, and probably with C. l. impavidus distributed to the west.

From Project Gutenberg

The six specimens examined do not present any significant difference in size and shape of the skull from specimens of scottii from Arizona, except that one skull from the Sierra de Tamaulipas is smaller than the others, suggesting intergradation between the subspecies scottii and tropicalis from farther south.

From Project Gutenberg

None of the specimens suggests intergradation in color between nivalis and longala, but some are slightly larger than specimens of the former from Veracruz.

From Project Gutenberg

The lines between these subspecies are difficult to establish because the zones of intergradation are broad.

From Project Gutenberg