Collagen is a part of the connective tissue that in the skin helps in firmness, suppleness and constant renewal of skin cells. Collagen is vital for skin elasticity. Ligaments are another type of connective tissue that attach two bones and consequently hold the joints together.
There are at least 33 phyla (plural of phylum) of animals. Humans are members of the phylum Chordata. All of the chordates have elongated bilaterally symmetrical bodies. That is to say, the left and right sides are essentially mirror images of each other.
Of the great apes, humans share 98.8 percent of their DNA with bonobos and chimpanzees. Humans and gorillas share 98.4 percent of their DNA. Once the apes are not native to Africa however, the differences in DNA increase. Humans and orangutans share 96.9 percent of their DNA. Humans and monkeys share approximately 93 percent.