a. A shared ancestral character.
Explanation:
The condition of birds and mammals having four limbs is a shared ancestral character because the structure of the limbs are similar in both the cases.
The forelimbs of the bird are modified into wings to aid flying.The hind limbs are modified into feel and claws.
These are homologous structures to the hands and feet in mammals.
That means they have a common origin, and hence are shared ancestral character.
The outer core of Mars cooled too quickly and the magnetic field didn't have time to fully form so the solar winds destroyed the magnetic field and the atmosphere
4.75 billion years ago, a large star near what is now the Solar System went supernova, sending heavy element debris outward into the galaxy. Some of the debris, after traveling long distances through space, collided with a Hydrogen cloud.
✯Hello✯
↪ In our life time, I dont think so
↪ They will be making some robots but I think before any of this happens they will have to find a way to modify genes
↪ By modifying genes this could change people's hair and eye colour build etc
↪ This hasnt had any progress, but is sure to come in the future but I dont think unless there is a scientific revolution that humans will be engineered this way in our life span
❤Gianna❤
