Natural Selection
One of the main ways a species evolves is because some organisms with some traits survive and reproduce better than others. This process is known as ____________________________________
Natural Selection
Which pattern of evolution does this describe?
Multiple species evolving from a common ancestor
Divergent Evolution
Scientists can explore whether two different animal species have evolved from a common ancestor, using evidence from all of the sources below except
a. analysis of strands of DNA
b. comparisons of bones and muscles
c. comparison of the experiences of each organism
d. studies of embryos during development
c. comparison of the experiences of each organism
What do all organisms on a phylogenetic tree have in common?
a common ancestor
Most genetic diversity comes from this source
genetic mutations
Which pattern of evolution does this describe?
Burst of evolutionary change followed by periods of stability.
Punctuated Equilibrium
Early during development, organisms as diverse as a human, a mouse, and a bat can appear indistinguishable. All of their embryos look nearly identical, suggesting that
a. during development, humans go through stages of being a mouse and a bat
b. similar structures have developed because of convergent evolution
c. these very different species have a shared ancestry with all mammals
d. this is coincidental resemblance between them
c. these very different species have a shared ancestry with all mammals
According to binomial nomenclature, species are given two names based on their ______ and _______.
genus and species
What is ONE advantage and ONE disadvantage of peacocks having long tails?
Advantage: easier to attract a mate
Disadvantage: more easily seen by predators, tail is hard to carry around
Which pattern of evolution does this describe?
Formation of a new species from a pre-existing species.
Speciation
Ostriches have wings, but do not fly. Humans have an appendix with no apparent function. Whales contain bones for rear legs. Each of these are examples of
vestigial structures
List the correct hierarchy of classification, going from broadest to most specific.
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
During a period of droughts in the Desert, seeds that are small and easily eaten become rarer, leaving mostly seeds that are large with hard-cased shells behind. The only birds that can eat these particular seeds are those with large beaks. If the drought continues for several more years, what should be expected to happen as a result of natural selection?
More small-beaked birds will die than larger-beaked birds. The offspring produced in the following generations will have a higher percentage of birds with larger beaks.
Which pattern of evolution does this describe?
When two organisms evolve in response to the other.
Coevolution
Two bodily structures, found in different species, have different internal bone structures but serve a similar purpose in each organism. This is most likely describing
analogous structures
What are 2 pieces of evidence do scientists use to create phylogenetic trees
shared morphology, genes, and behaviors
A forest has many trees and bushes that produce nuts. This a major food source for many species, including a particular bird. Birds of this species have a variety in beak shapes ranging from long and pointy to short and hard. The birds with short and hard beaks are able to eat the nuts better than the birds with long and pointy beaks. What do you expect to happen to this population of birds over time, in terms of what you know about evolution? Include all 4 principles of natural selection in your explanation.
More birds than food will create competition for limited resources. Some birds have shorter beaks, and others have long and pointy beaks = variation. Short beaks are adaptations that help the birds in this environment survive. Because of this, over time birds with short beaks should live longer, and thus reproduce more, than other birds so that short beaks become more common = descent with modification
The red fox lives in mixed farmlands and forests, where its red color blends in with tree bark. The kit fox lives on the plains and in deserts, where its sandy color conceals it from predators. The ears of the kit fox are larger than the red fox to increase surface area to release heat. Similarities in structure indicate that the red fox and kit fox had a common ancestor. Is this convergent or divergent evolution? EXPLAIN
Divergent evolution because common ancestor, different color due to evolving in different environments
List two of the five fields of science discussed in class and why/how they provide evidence for evolution.
Note: do NOT just give definitions!
• Paleontology = The fossil record reveals a history of the types of organisms that have lived on Earth. Transitional fossils link ancestral species to their decedents
• Morphology = similar structures suggest evidence of common ancestry. Vestigial structures are evidence of divergent evolution.
• Biogeography matches what we predict happened with continental drift and provides evidence of divergent evolution.
•Embryology reveals that vertebrate embryos have many similarities when developing in the womb and thus could reflect common ancestry.
• Biochemistry = Analyzing DNA and proteins from different species allows us to compare similarities to predict common ancestry. Closely related species would have similar DNA sequences.
What are the 3 things we can learn from a phylogenetic tree?
1. which groups are most closely related
2. which groups are least closely related
3. which groups diverged first