Chapter 21 - Phylogeny, Speciation, and Extinction 

Murchison meteorite

The ________ (discovered in Australia in 1969) included sugars and over 70 distinct amino acids, lending support to this notion.

Inorganic materials

________ found in Earth's early atmosphere reacted to form the building blocks of living molecules.

distinct species

Plants that generate extra sets of chromosomes are frequently unable to interbreed with plants that retain the original number of chromosomes, and hence evolve into a(n) ________ over time.

Phylogeny

________ is the study of the evolutionary history of a species or group.

Adaptive radiation

________, the development of organisms into diverse species that occupy different ecological niches, can result from speciation.

sexual selection

In animals, ________ can also result in sympatric speciation.

Meteorites

________ are considered to have battered early Earth.

Morphological evidence

________ from fossils reveals features that are acquired or lost over time, which may be utilized to build phylogenetic trees.

Human

________- caused ecological pressures, like as habitat degradation or overhunting, can raise extinction rates.

Prezygotic

________ or postzygotic reproductive obstacles can induce speciation.

Extinction

________ (the extinction of all individuals of a species) has occurred throughout Earth's history, as evidenced by the fossil record.

Phylogenetic trees

________ and cladograms are theories regarding the evolution of organisms across time, with ________ reflecting the approximate timing of evolutionary events.

Postzygotic barriers

________ exist after the zygote is produced and prevent it from maturing into a viable and fruitful adult organism.

evolution of new species

The ________ is referred to as speciation.

Prezygotic barriers

________ are impediments that inhibit the creation of a zygote, or fertilized egg.