Do Hippos and Spiders Share a Common Ancestor?

Answer 1

Of course they do. It was a worm like creature that also possessed light sensing neurons, a heart, a central nervous system, and multisegmentation homeobox genes. And it lived about 600 million years ago. Even today, Hippos and spiders share ~70% of their functional DNA. For instance, both utilize Krebs cycle metabolism of glucose to generate ATP, for instance. Only a very small ignorant mind would say that they don't share a common ancestor. If you are curious, I highly recommend the book: "The Ancestor's Tale", by Richard Dawkins, available on Amazon and in many local bookstores.

Answer 2

Well, yes.

Humans are much more closely related to hippos than spiders because we are both mammals. Mammals are more closely related to reptiles than amphibians. Mammals are more closely related to amphibians than fish. Mammals are more closely related to fish than spiders and other arthropods.

The separation between the mammal line and arthropods is when the arthrapod ancestors later developed a chitinous outer shell for protection. Our ancestors retained a soft body.

There is another division however. During early develoment after the fertilized egg divides many times to form a group of cells (blastula) a cleft forms that grows to make the blastula hollow. In our group, the Deuterostome, this cleft becomes the anus. In the other group, the Protostome, this cleft becomes the mouth. Humans and fish are Deuterostome while spiders are Protostomes.

The furthest back that I know of for hippos would be the Cephalochordata. http://www.ucmp.berkeley.edu/chordata/cephalo.html
These would be about halfway between a primative round worm and fish.

Regular round worms are already branched away as Protostome. The most primative ancestor of arthropods is probably something like Cephalorhyncha
http://www.ucmp.berkeley.edu/phyla/ecdysozoa/cephalorhyncha.html
These are about halfway between round worms and arthropods

Answer 3

Sure do: Arachnopotamus! Sorry, couldn't resist that one.

In seriousness, they have a common ancestor, but its almost impossible to say how far back in the evolutionary chain this lies. This is mainly due to this fossil record of most invertibrates - they are so soft and squishy, they just disappear without a trace. Since insects (arthropods) are a completely different phylum than hippopotami (chordata) we have to go back to the oceans to find a common ancestor. Acutally, we have to go far back in the oceans, before the development of fish, mollusks, and worms to get to a common ancestor. This was likely some sort of jelly-like tube - very soft and fragile and simply fed on small cellular (or barely multicellular) organisms to survive. Again, we know nothing about this type of creature, except that the evidence we have gatered to date suggests that it existed.

Long answer, short: Yes. Way, way, way, way, way far back.

Answer 4

yes

Answer 5

yes, we all do. if you are a believer of the bigbang theory. :)

Answer 6

yes, but very very long ago.