Among flowering plants, cactus-like species are found in desert-living members o

Question

Among flowering plants, cactus-like species are found in desert-living members of the cactus family (naturally), as well as the spurge family and the milkweed family. These families are each monophyletic groups, but they are quite unrelated to each other (they are not sister clades). Within flowering plants, the cactus-like growth habit is best considered to be the result of _________________ and is a form of _______________.
1) evolutionary reversal; synapomorphy
2) convergent evolution; homoplasy
3) synapomorphy; homology
4) polymorphism; shared ancestral character state
5) convergent evolution; shared derived trait

Explanation / Answer

Answer will be : Convergent Evolution and Homoplasy

Explanation:

1) Convergent Evolution : It is independent evolution of certain similar characters in species of different lineage or origin or different ancestors.

It occurs because all these species live under similar environment factors and forces. So they gradually evolve similar structures despites belonging to different ancestors. Such features are called Analogous Structures. It means they have resembles of forms and function to sustain certain environmental conditions. These analogous characters re absent in their last common ancestors.

In given question, families are monophylactic but with different clade ( different ancestor) and also growing in similar cactus like habitat /environmental conditions ,so will evolve same analogous structurs.

Thus type of evolution will be : Convergent evolution.

2) Homoplasy: In the most simple language, it is evolution of similar functional structures in different species of different lineages under similar Environmental conditions due to Convergent evolution.

so basically, it is the form/outcome of Convergent Evoloution in the form of ANALOGOUS STURCTURE.

So now u must have understood the answer.

# HOMOLOGY : It is similarity of structures or developmental features due to their COMMON ANCESTOR.

# SYNAPOMORPHY : when two species derive same characters from their common ancestors through evolution.

It is not the case in given question. so both options are ruled out.

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