Evolution Chapter 14 homework part 2

From the fossil record, they determine for how long each species is found in the geologic record. From this information, paleontologists can follow patterns of _______ and the evolution of clades.

• Allele frequencies

• Protein mutations

• Species turnover

Select two reasons why speciation events can be difficult to discern when examining the fossil record.

• Species are defined by reproductive isolation, which cannot be shown from fossils.

• The fossil record of speciation events are often destroyed when paleontologists dig for fossils.

• In the early stages after speciation, little change in physical appearance of new species may have occurred.

• Speciation events are sometimes lost from the fossil record due to plate tectonics.

Identify whether each scenario is an example of punctuated equilibria or anagenesis.

Paleontologists discover a sequence of marine worm fossils that has a gradual series of changes with gaps that can be explained by disturbance to the geological strata.

• anagenesis

• punctuated equilibria

Identify whether each scenario is an example of punctuated equilibria or anagenesis.

Paleontologists discover a sequence of clam fossils that has large changes in morphology over shallow depths of fossil layers.

• punctuated equilibria

• anagenesis

Identify whether each scenario is an example of punctuated equilibria or anagenesis.

Phylogenetic analysis of living and fossil Bryozoa in the genus Metrarabdotos showed long branches with splits deeper in the tree occuring nearly simultaneously.

• Punctuated equilibria

• anagenesis

Identify whether each scenario is an example of punctuated equilibria or anagenesis.

Paleontologists discover a sequence of fossil molar teeth of grass feeding voles with all transitional forms present in a graded series.

• punctuated equilibria

• anagenesis

Identify which scenarios are likely to give rise to adaptive radiation.

• Insects developed wings over many generations, allowing them to gradually inhabit new ecological niches.

• The extinction of dinosaurs decreased competition for resources, allowing large mammals to rapidly evolve.

• A flood event connects a river to a new lake, allowing species of fish to quickly diversify into new ecological niches.

• The steady decline and eventual extinction of a competitor species allows a stickleback fish population to increase.

• Beetles evolved elytra, hardened forewings that protect their hindwings, allowing the clade to diversify rapidly.

Identify the mechanism in each scenario that led to adaptive radiation.

Over fifteen million years ago, marsupials were the only mammals on the island of Australia. Since then, marsupials have radiated into over 200 species today, from the wombat to the Tasmanian wolf.

• Colonization

• Environmental Change

• Key innovation

• Competitor or Predator Extiction

Identify the mechanism in each scenario that led to adaptive radiation.

After the expansion of grasslands in North America during the Miocene epoch, horses radiated quickly into a range of morphologies, including the number and arrangement of teeth, suitable for grazing on rough vegetation.

• Environmental Change

• Colonization

• Key innovation

• Competitor or predator extinction

Identify the mechanism in each scenario that led to adaptive radiation.

Some evolutionary biologists have proposed that the evolution of the sticky toe pad of Caribbean anole lizards has allowed the species to interact with its environment in a novel way, thus facilitating access to new resources.

• Colonization

• Competitor or predator Extinction

• Key innovation

• Environmental Change