Homology- Cheetahs and Lions
Cheetahs
evolved 4-6millon years ago. They are part of the cat family and evolved from
domestic cats, wildcats, and all the way back to saber-tooth cats. Cheetahs are
the only members of the Acinonyx group. The cheetah lineage is a group of cats with similar characteristics, slender
with long limbs. Cheetahs have a distinctive skull and dental morphology making
them unique and different from other cats.
Chloe Schneider.
Cheetah - Favorite Living Organism Research Project BIO20I.
http://prezi.com/utugobboophu/cheetah-favorite-living-organism-research-project-bio20i/.
2014, July 03.
Lions are the most social of the cats, living in family
groups called prides, consisting of four to twelve related adult females, their
young, and one to six adult males. Adult male lions weigh between 300 and 500
pounds (135 and 225 kilograms), while the female weighs about 300 pounds (135
kilograms). Lions are a light tawny color with black markings on the abdomen,
legs, ears, and mane. Lions live up to 15 years, reaching sexual maturity in
their third year.
http://www.scienceclarified.com/Ex-Ga/Felines.html#ixzz36SxWSdm1
http://www.scienceclarified.com/Ex-Ga/Felines.html#ixzz36SxWSdm1
The
Cheetah and the Lion both have tongues covered in papillae which they use to
scrape the meat from their prey and groom themselves.
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| Lion |
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| Cheetah |
Analogy- Cheetahs and Dogs
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| Domestic Dog |
Dogs
were probably the first tame animals. They have accompanied humans for some
10,000 years. Today humans have bred hundreds of different domestic dog
breeds—some of which could never survive in the wild. Despite their many shapes and sizes all
domestic dogs are members of the same species—Canis
familiaris. Domestic dogs
still share many behaviors with their wild relatives. Both defend their
territories and mark them by urinating on trees, rocks, fence posts, and other
suitable sites. Many pet dogs also bury bones or favorite toys for future use,
just as their wild relatives sometimes bury a kill to secure the meat for later
feasts.
Domestic Dog-Canis familiaris http://animals.nationalgeographic.com/animals/mammals/domestic-dog/
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| Cheetah and Domestic Dog- Being Friendly |
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| Cheetah |
.jpg) |
| Dog- Front Paws |
A dog's paws are the
shock absorbers of his foot and pastern (wrist). A dog is not as deft as a cat
with his paws. He cannot clean himself or "grab" his prey like a cat
can. Rather, a dog uses his paws to dig and scratch. Walking and running are
really the best uses for a dog's paws. There
are five pads on a dog's foot. One is on each of the four toes, and a larger
pad is centered in the "palm" of the foot.
http://www.ehow.com/about_6397161_anatomy-dog-paws.html
http://www.ehow.com/about_6397161_anatomy-dog-paws.html
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| Cheetah-back Paws |
Cheetah paws are
less rounded and harder than other cats' which helps the cheetah make quick
turns. Cheetah claws are semi-retractable and aid in acceleration. The
"thumb" claw or dew claw (at right bottom) is positioned back of the
other 4 and higher. This claw is used to hook prey during the chase.
http://www.cheetahspot.com/claws.php
Good opening descriptions for both your homologous and analogous traits.
ReplyDeleteSome clarification: Homologous traits share a common ancestry but have differences due to being used in functionally different ways, usually because of differences in the environment (think the eagle wing and the penguin wing).
You are highlighting the papillae on the tongue of two organisms of cats, so ancestry is not really in question, but you have not explained how these traits differ between the two species and why. You need to find the difference in the papillae or else these are just shared hereditary traits, not homologs.
One way you could have gone with this pair of organisms is with reference to camouflage. The coat/fur is a ancestral trait but has obvious differences due to different environments. Spots work best for camouflage in the leopard, who tends to live in the trees and takes advantage of the dappling from the leaves. Living in the hot, flat grasslands, generally brown in color, lions have developed a camouflage that helps them blend in and hide from their prey. The coat patterns are homologous traits.
While I do see the differences in function of the dog and cat paws, remember that for analogs we are looking for similarities dues to *similar* function, but arising independently, not through common descent. The problem here is that, while dogs and cats are from different families, they aren't that distantly related and they likely inherited their foot structure from a common ancestor. That would make these common shared traits, or even homologs (if there is a structural difference explained by environmental differences) but not analogs. What information do you have on the ancestry of these two organisms and what does that tell you about the origin of the foot structure? Did it arise from common descent or did it arise independently in both species? That is what you need to find out to see if they are analogs.
You provided a lot of good information about the animals and I especially like the homologous trait that you chose. It's almost creepy how they have teeth on their tongues just to efficiently eat the meat off bones.
ReplyDeleteI thought your post about these cats and dogs was very interesting but somewhat off topic from the guideline.
I enjoyed reading your analysis on the trait of tongue papillae; I didn't know that the tongue's roughness was used to scrape the meet off prey. I used to think it was mostly for grooming purposes. However, while your post was very informative about a few common traits and their purposes, it wasn't very clear if they were homologous or analogous. The similarities between cats and dogs seem very close to each other, and it seems likely to me that their common ancestor might have had these traits. But that wasn't clearly addressed in your post.
ReplyDelete