Clement’s organismic model - Competition causes sharp boundaries between groups of species; certain species group together.

TLS Online TPP Program

#Id: 2155

#Unit 9. Diversity of Life Forms

Use more rapidly evolving parts of the genome to estimate phylogenies in the recent past. More slowly evolving parts for deeper evolutionary time.

TLS Online TPP Program

#Id: 2156

#Unit 9. Diversity of Life Forms

Radiation- Several species arise from a common ancestor over a short time

TLS Online TPP Program

#Id: 2157

#Unit 9. Diversity of Life Forms

Phylogenetic relationships among species in a radiation are difficult to determine for two related reasons.                                                                 

a. During the short time between two successive speciation events, few new mutations are fixed.                                                                               

b. Incomplete lineage sorting may occur during rapid diversification.

TLS Online TPP Program

#Id: 2158

#Unit 9. Diversity of Life Forms

TLS Online TPP Program

#Id: 2159

#Unit 9. Diversity of Life Forms

Animal Kingdom is characterized by multicellular, eukaryotic organisms. The cells lack cell walls.

TLS Online TPP Program

#Id: 2160

#Unit 9. Diversity of Life Forms

They ingest and digest food (holozoic), hence they are heterotrophic. Higher forms show elaborate sensory and neuromotor systems. Majority of them are motile.