Question

What causes some Orders to have many species and others few? For example, there are only three species in the Order Proboscidea.

Answer 1

While taking an example of insects , animals who evolved around 480 million years ago. The 6 million species living in all environments while occupying an unbelievable variety of niches. unexpectedly despite the fact that, they have on no account actually personalized to the marine environment.

As among the key explanations has been geological age –as the older groups of organisms are more diverse since they have purely had extra time to amass larger figures of species.

This is clearly shown by the fact that a number of relatively young groups of species are amazingly diverse but some exceptions like the Methanopyri which are very ancient but species poor.

plants species production rate is twice that of animals, while multifaceted organisms have created new species at a speed approximately 10 times that of simpler one ( prokaryotes).

Sex which seems to be a foremost catalyst for escalating the rate of producing new species which explains its accomplishment as an evolutionary plan.

Amongst the vertebrates, a terrestrial existence seems to clarify greater species diversity. While aas marine versus non-marine habitat may possibly be the main cause for high species number in some major invertebrate groups.

As of insects, who have adopted herbivory was most likely the answer to clearing up high rates of new species forming in the past while showing outstandingly variety today.