Lizard Evolution Virtual Lab
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Arkansas Tech University *
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Course
1004
Subject
Anthropology
Date
Dec 6, 2023
Type
Pages
5
Uploaded by KidScience1079
NAME: Cameron McCaskill
LIZARD EVOLUTION VIRTUAL LAB
(modified from HHMI BioInteractive)
This is a virtual lab that you will complete by visiting the following website:
https://media.hhmi.org/biointeractive/vlabs/lizard2/?_ga=2.58808621.1835329789.1524696844-20795
16126.1524696844
Answer the following questions as you finish each module of the virtual lab or as a final assessment
after completing the entire virtual lab.
Module 1: Ecomorphs
1.At the beginning of the virtual lab, you were asked to sort eight lizards into categories. What criteria
did you initially use to make your groups? Did you revise your criteria later? Why?
I based my criteria on the size of the anoles' legs. I did not revise my criteria later. I chose the size of
the anoles' legs because I believe that each of the different anoles had evolved based on their habitat,
and I wanted to base my experiment on that.
2.An adaptation is a structure or function that is common in a population because it enhances the
ability to survive and reproduce in a particular environment. Provide one example and an explanation
of one adaptation in the
Anolis
lizards.
One adaptation is the short legs on the sheplani hispaniola anolis lizard. This is most likely due to the
slim branch it lives on. The short legs make the lizard able to hold onto the branch/twig better and
survive longer because it does not fall off.
3.Provide one evolutionary explanation for why lizards living in the same part of the habitat (i.e.,grass)
would have similar characteristics.
Lizards in the same habitat would have similar characteristics because there are many ways to do
something, however there is only one way that is the best for surviving. Basically, lizards in the same
habitat have the characteristics that are most fit for survival, so most lizards in that habitat would
exhibit those most fit characteristics.
4.What is an ecomorph? Provide one example from the virtual lab.
Ecomorphs are species with similar body types and habitats. "eco" stands for ecological niche and
"morph" for morphology, or shape. An example is how the sheplani Hispaniola and occultus Puerto
Rico lizards both have short legs, but with slight
5.How is an ecomorph different from a species?
An ecomorph is different from a species because it only classifies the organism as having similar body
types and habitats, however species have other different characteristics such as color or look.
6.Explain how a particular body feature of one of the lizard ecomorphs from the virtual lab is an
adaptation to their particular niche.
One of the lizard ecomorphs, the occultus Puerto Rico anole has short legs because it needs to
be able to stick to/crawl on slim twigs in their habitat.
Module 2: Phylogeny
1.In module 1, you identified which species of lizards were most similar to one another based on
relative limb length and toe pad size. In this module, you determined which lizards are more similar to
one another based on what type of information?
I determined which lizards are more similar based on DNA sequence analysis.
2.Are the species of lizard that are more similar to one another according to body type also more
closely related based on the results obtained in this module? Explain your answer.
The species that are similar according to body type are not more closely related based on the results
obtained from the DNA sequence analysis. This is because similar body types are farther away from
each other on the phylogeny tree.
3.The figures below show two phylogenetic trees similar to the one you constructed in the virtual lab
but with more lizards. The trees below show the evolutionary relationships among species from four
ecomorphs from the four largest Caribbean islands.
Figure 1.
Phylogeny of anole
lizards on four of the major
Caribbean islands color-coded
according to geographical
distribution. Light dotted line,
Puerto Rico; small dashed line,
Cuba; large dashed line,
Hispaniola; and solid line, Jamaica.
Figure 2.
Phylogeny of anole lizards in the four major Caribbean islands colored in according to
ecomorph. Light dotted line, twig; small dashed line, trunk-ground; large dashed line, trunk-crown;
solid line, grass-bus.
What conclusion can you draw about the evolution of the
Anolis
lizards based on these figures?
The conclusion I can draw about the evolution of the Anolis lizards is based on ecological niches on an
island rather than the entire island itself. Two anoles on different islands can have similar traits as long
as their ecological niches are similar.
4.What is convergent evolution? Use evidence from the trees to explain how the
Anolis
lizards arean
example of this concept.
Convergent evolution is where organisms that aren't closely related, independently evolve and have
similar traits due to similar environments or ecological niches. The phylogenetic trees show this type
of evolution because similar traits are based on environments, and not location/species type. For
example, anolis cybotes and anolis sagrei both are trunk ground anoles, but live on different islands.
Module 3: Experimental Data
1.In Dr. Losos’s experiment, why was it important that the experimental islands lacked lizards?
It was important because it allowed each ecomorph to be isolated and easier to study their evolutions.
2.Dr. Losos’s data suggest that after only a few generations, the lizards on the experimental islands
have shorter legs on average than the lizards on the larger island. Explain how the data you collected
either supports or does not support this claim.
The data I collected supported Dr. Losos' claim by showing that because the environment on
the island was more suited for shorter legs, the lizards evolved to have shorter legs. Ecomorphs
are based on ancestral causes, not geological location/isolation, so the anoles evolved with
shorter legs because shorter legs increased their chances of survival.
3.Based on what you know about the experimental islands and the lizards that were placed on these
islands, explain how and why the average leg length of the population might change overtime. Include
the concept of natural selection in your discussion.
The average leg length of the population will shrink because of the environment/ecological
niches of the experimental island. Because the advantage of longer legs has been lost, some of
the anoles will evolve with shorter legs, and some will not. The ones with shorter legs will
survive better and the ones with longer legs will survive worse/die off. Therefore, in the end
anoles with shorter legs will dominate the population. This process is called natural selection.
4.If the population from one of the experimental islands were reintroduced on the original island,do
you predict that lizards from the two populations would still mate and reproduce? Justify your answer
with scientific arguments.
The lizards from the two populations, both short legged and long legged will still mate and
reproduce because the lizards are still of the same species and because it will increase their
species chances of survival.
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