Up Next
Back to Show
Watch Preview
Changing Seas
Sponges: Oldest Creatures in the Sea?
Season 8
Episode 1
Until recently there was scientific consensus that sponges were the first animals to branch off the “Animal Tree of Life,” a kind of family tree for all living and extinct animals on earth. But recent DNA research has cast doubt on that theory, with some scientists suggesting that ctenophores, also known as comb jellies, are an older lineage.
Support Provided By
Season
26:42
Experts study southern sea otters to ensure their longtime survival on California’s coast.
26:42
Islanders restore Maui's watersheds through traditional Hawaiian wisdom.
26:42
Florida scientists make remarkable discoveries about whitespotted eagle rays.
26:42
Marine archaeologists uncover a Roman shipwreck on Croatia's Adriatic Coast.
Unlock with PBS Passport
26:42
Researchers brave the Arctic’s cold and dark to reveal the mysteries of the Polar Night.
Unlock with PBS Passport
26:42
Amid shipwrecks and shifting sands, Bermuda’s corals offer clues to climate resilience.
Unlock with PBS Passport
26:42
Knowledgeable fishers collaborate with scientists to keep sharks abundant.
26:42
Researchers and citizen scientists document the fascinating lives of seashells.
Unlock with PBS Passport
26:42
Florida’s gentle giants are dying in record numbers.
Unlock with PBS Passport
26:42
Experts are working to conserve and restore the Puget Sound’s declining kelp forests.
Unlock with PBS Passport
26:42
Scientists study the body size and health of humpback whales across their migratory cycle.
26:42
Experts study declines in the number of humpbacks migrating between Alaska and Hawaiʻi.