<h2>540 million years ago
</h2>
Paleozoic.
Era immediately follows Precambrian It lasted about 4.5 billion years.
When did abundant fossil evidence first appear in the geologic record.
540 million years ago.
Answer: Hydrogen bonds.
Explanation: This seems like more of a chemistry question, but basically hydrogen bonding is way stronger than any other kinds of bonding, and because water molecules are all hydrogen bonded, they cling together a bunch and are thus super cohesive.
Acquired characteristics are gotten and learned characteristics while inherited characteristics is gotten from the organisms parent