Learning from the Fossil Record
Grade 8 Science
Name: Caroline Burns
Date: 3/14/11
Impact of Environment on Traits Pre/Post Assessment
Answer the following questions to the best of your ability.
1.
How do the traits of living things depend on the environment? Answer this question in RASE.
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Traits of livings things depend on the environment because it is what they need to survive. This is
because without the environment there wouldn’t be any water from lakes, rivers, or oceans. There
wouldn’t be trees with leaves that animals would need for food. Especially for herbivores, because all
they eat are leaves, and vegetables, and nothing that is meat. In the environment the natural resources
create shelters for animals and give them places to hide to sneak up on predators. The environment
gives the trait being short the ability to walk under trees, and if they can jump high, trees let the animals
jump up to try and get food. Traits also depend on the environment because they could have a trait that
gives them an advantage or a trait that gives them a disadvantage. By having the advantage trait the
environment enables the organisms to live longer, and reproduce more with the same species. This
means that they can have more offspring. But if the animal has the trait with the disadvantage the
environment doesn’t help the organism live long, which then means they can’t reproduce to have
babies. This is how traits of living things depend on the environment.
Learning from the Fossil Record
Grade 8 Science
Name: Caroline Burns
Date: 3/14/11
2. The sloth has changed over time. The earliest fossils of the sloth show that is was a much larger
animal that lived on the ground and had a long tail. Today, the sloth is smaller and lives in trees
and has no tail. Similarities still exist however. The sloth has always eaten leaves from trees and
contained large claws. Explain how and why the sloth has changed so much over time. Use the
pictures below to help provide an answer in RASE format.
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Ancient Sloth
Sloth Today
The sloth has changed so much overtime because it needed to change to survive. It might have
needed to change from really tall to short, because it was a way that would enable the sloth to live
linger, and have more offspring. the environment was mainly trees. And being short enables them to
climb up to the top of the tree to get the leaves, and enables them to reach the bottom of the tree
easily to get the leaves down there also. and just hang there. Being tall doesn’t let them reach up the
bottom of the trees, and since they are big it is hard to maneuver around in the trees and not make a lot
of noise at the same time. They still eat leaves because they still live in environments with lots of trees
and they didn’t get a mutation for what they eat. The moths also still have claws because it enables
them to hang onto the trees and protect themselves from predators. If they had gotten a mutated gene
for no claws, it would make it harder to live in their environment and produce more offspring. The
changes that the sloth’s got were so they could “survive to the fittis”!