Because an amino acid<span> cannot be </span><span>synthesized</span><span> by the organism, and it must be supplied in its diet.</span>
Every person has their own part to play or if you want to get scientific then a niche. And if somebody doesn't do their job then it could slow everyone else down. Maybe I don't fully understand the question, But I hope its right.
Answer:
What was the first hominid ancestor?
The first early hominid from Africa, the Taung child, as it was known, was a juvenile member of Australopithecus africanus, a species that lived one million to two million years ago, though at the time skeptical scientists said the chimpanzee-size braincase was too small for a hominid.