Most skull bones are formed by ossification, but other bones are formed by ossification.

Intramembranous, Endochondral

Explanation:

Fibrous membrane and hyaline cartilage are usually present at the beginning of all bone skeletons in an embryo of six (6)weeks. The difference is that intramembranous ossification develops from the fibrous membrane while that of endochondral from the hyaline cartilage. Ossification is driven by osteoblasts which are the main cell of bones.

amber has allowed scientists to study dna that has been preserved over millions of years.

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.