The genetic change in a population or species over many generations is evolution. Whether it be physical or mental increase.
Answer:
Fraternal twins can be different genders because they are two completely different eggs getting fertilized; but even two same gender fraternal twins do not look completely alike. Whereas for identical twins since one egg is splitting into two, the two cells have the same exact DNA make up and chromosomes.
I also believe the technical part of it is to do with genetics, like ressesive and dominant genes, because they can be the same gender, ex. both girls and one has blue eyes, fair skin, and blonde hair, the other twin has brown eyes, black hair and tan skin. The parents could be part of the genes but there is also grandparents maybe the mom's mom has blonde hair and blue eyes, with fair skin. But the dad he has brown eyes, black hair and tan skin. The moms genes were recessive, but the grandma's genes were dominant.
I tried to explain it as best as I could I hope it helps!
Answer:
Do you mean planets?
if so,The heavy rocky particles within the inner part of the disk formed planetesimals and eventually, inner planets. In our solar system, the four innermost planets Mercury, Venus, Earth and Mars are known as inner planets. They lie inside the asteroid belt. They have volcanoes and valleys and are very hot compared to outer planets.Inner planets are much smaller than the outer planets, and are rocky with an iron core.
Hope that helps!
