Natural selection is an idea that Charles Darwin came up with.
It attempts to describe how animals and plants evolved by using nature as the determiner of who survives. For example, if there is a fast cheetah population and a slow cheetah population in Africa, the slow cheetah population will eventually die out due to them not being able to catch prey to survive. The fast cheetah had the desirable traits necessary for survival in this location. Only the strong survive is helpful to remember when dealing with natural selection.
These structures have the function to move around.
Option: C
Explanation:
Tortoise is one animal who used to hide its body under a protective shell. To move its body parts take sharp bend and move around. It belongs to reptile family. It has four legs. Turtle's leg only appeared when it move on the land surface. It takes much time to move. Whole body remain under the shed of hard shell.
Turtles easily move into the water. They are good swimmer. They faced difficulties in moving on the ground mainly on undulating surface. They move very awkwardly. Their body weight is very heavy that is one of the problem in crawling.
The body itself. be it immune cells, muscle cells, or blood cells. or nerve cells.
So you do A^2 + b^2=C^2
(12X12)+(16X16)= 256+144=400 then fine the square root which is 20 so the answer is 20!
Hope I could help!
<span>1. Bipedal gait
2. free to use hands for tools or carring capacity
3. increase in cranial capacity
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Evidence points to bipedalism evolving before the expansion in human brain size. The different hypotheses are not necessarily mutually exclusive and a number of selective forces may have acted together to lead to human bipedalism. </span>
