Speciation & Classification Review

Flashcards based on Speciation & Classification Review Sheet

What is convergent evolution? Give an example

When unrelated species share the same function in the same or similar environments they may evolve similar structures. For example the wings of a bat, a bird, and a dragonfly all are outwardly similar because the shape of the wing is best for the function of flying, NOT because they are closely related.

What is divergent evolution? Give an example

Accumulation of differences between closely related populations within a species, leading to speciation. An example is Darwin’s finches.

What is speciation? Give an example.

Formation of a new species from a common ancestor through divergent evolution

Name 3 barriers that can isolate populations and give an example of each one:

a. geographic isolation- mountain b.behavioral isolation- different mating call or ritual c.temporal isolation- different mating seasons

In order for speciation to occur, organisms must ultimately become isolated.

reproductively

A horse and a donkey can produce a sterile mule; therefore, horses and donkeys are the same species. Is this statement true or false? Explain your answer.

False. Mules are sterile and cannot reproduce. Therefore a horse and donkey are different species.

What is adaptive radiation? Explain how homologous structures support the idea of adaptive radiation.

When a population or a species evolve to fill in niches that were previously unoccupied. Darwin’s finches filled in the gaps of eating insects, nectar, nuts, etc. in order to maximize food consumption for energy and therefore different beaks had different advantages depending on food availability. These beaks are homologous and diverged.

In the name Rhizopus nigricans, ___ is the genus

Rhizopus

In the name Rhizopus nigricans, is the species.

nigricans

Give the classification groups in order from largest to smallest starting with domain and ending with species.

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

What is the smallest taxonomic category shown in the Figure in which all members are not bears?

Order Carnivora

What does a cladogram show?

Shared characteristics

What is a derived character?

trait that arose in the most common ancestor of a particular lineage and was passed along to its descendants

How do taxonomists use the DNA sequences of species to determine how closely two species are related?

If the DNA sequences of two species are more similar then they share a more recent common ancestor. If the DNA sequences of two species are more different then they share a more distant common ancestor.

How are convergent evolution and analogous structures related?

Analogous structures are evidence of convergent evolution

How are divergent evolution and homologous structures related?

Homologous structures are evidence of divergent evolution

What is the difference between allopatric and sympatric speciation?

Allopatric speciation occurs when the two species diverge in geographically different location while sympatric speciation occurs in the same location

How is sympatric speciation even possible? Why doesn’t competition lead to the “fittest” surviving and the “loser” going extinct?

Species are able to find different microenvironments within the same geographic location and the differences in these microenvironments leads to different advantages and thus evolution

Which organism is the common ancestor for all of the other organisms?

Primelephas

Is Loxodonta africana more closely related to Elephas maximus or Mammuthus primigenius? Explain your reasoning.

They are equally related because they all share the same common ancestor

What is the mode of nutrition for organisms in the Animal Kingdom?

Heterotroph