How were the first marine mammals able to compete successfully?

A coworker and I (both non-scientists) were discussing some TV shows about
dinosaurs and evolution we had seen recently. I remarked how fascinating I
find the fact that not only did marine organisms evolve into terrestrial
organisms, but later, after mammals evolved, we had the reverse. This got
us both to remark how tough it must have been for the first marine mammals
to compete with existing marine organisms, which had been around since the
dawn of time. What allowed marine mammals to survive and carve out a niche
for themselves? Was it their intelligence, social behaviors, or something
else?


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Relevant Pages

  • Re: How were the first marine mammals able to compete successfully?
    ... find the fact that not only did marine organisms evolve into terrestrial ... us both to remark how tough it must have been for the first marine mammals ... to compete with existing marine organisms, which had been around since the ... seem to compete quite well. ...
    (sci.bio.evolution)
  • Re: How were the first marine mammals able to compete successfully?
    ... dinosaurs and evolution we had seen recently. ... find the fact that not only did marine organisms evolve into terrestrial ... us both to remark how tough it must have been for the first marine mammals ... to compete with existing marine organisms, which had been around since the ...
    (sci.bio.evolution)
  • Re: How were the first marine mammals able to compete successfully?
    ... find the fact that not only did marine organisms evolve into terrestrial ... us both to remark how tough it must have been for the first marine mammals ... to compete with existing marine organisms, which had been around since the ...
    (sci.bio.evolution)
  • Re: How were the first marine mammals able to compete successfully?
    ... find the fact that not only did marine organisms evolve into terrestrial ... us both to remark how tough it must have been for the first marine mammals ... to compete with existing marine organisms, which had been around since the ... What allowed marine mammals to survive and carve out a niche ...
    (sci.bio.evolution)
  • Re: How were the first marine mammals able to compete successfully?
    ... to compete with existing marine organisms, which had been around since the ... What allowed marine mammals to survive and carve out a niche ... They remain essentially built like land animals, ... eating aquatic creatures much smaller than themselves. ...
    (sci.bio.evolution)