Question

The earliest classification systems grouped organisms based on

have focused on
to better understand evolutionary ancestry
Since then, newer classification systems

Answer 1

The earliest classification systems such as those developed by Aristotle and Linnaeus grouped organisms based on physical similarities. With the advance of evolutionary theory, the focus shifted to phylogeny, leading to the use of cladistics and the creation of phylogenetic trees to depict evolutionary relationships. These classifications are continually updated with new scientific discoveries.

Step-by-step explanation:

Early Classification Systems

The earliest classification systems grouped organisms mainly based on physical similarities. These systems, like the one developed by Aristotle or later refined by Linnaeus, were primarily concerned with grouping organisms that shared obvious traits. Linnaeus's hierarchy of taxa remains a foundational aspect of biological taxonomy, classifying life from the broadest kingdom down to individual species.

Phylogenetic Classification

After the publication of Darwin's theory of evolution, the focus of classification shifted towards phylogeny, which is the evolutionary history of organisms. Advances in systematics have allowed scientists to construct phylogenetic trees to hypothesize the evolutionary relationships among organisms. These hypotheses are modified as new evidence from DNA analysis, fossil records, and other biological disciplines emerge, providing a clearer picture of life's evolutionary pathways.

Current Trends in Classification

Classification today continues to evolve with scientific discovery. Recent genetic analyses have challenged earlier phylogenetic trees, necessitating revisions to reflect true evolutionary relationships. Biologists now commonly apply a cladistic approach, which involves arranging organisms based on common ancestry—clades—thereby creating a more accurate reflection of an organism's phylogeny.

Limitations and Ongoing Evolution of Classification

While the goal of classification is to depict the evolutionary history accurately, there are certain limitations. Sometimes closely related lineages may appear dissimilar due to different adaptive paths. The phylogenetic trees, being scientific hypotheses, change over time with continued research and discovery, as exemplified by the updated relationship between hippos and whales.

Answer 2

On the basis of physical traits.

Step-by-step explanation:

Newer classification systems classify organisms on the basis of physical traits of an organism. All modern classification systems gets their concept and help from Linnaean classification system. In these new classification systems, those organisms that have similar characteristics are placed in one group because they evolve from the same ancestor or having common ancestry. These changes occurs in the organisms with the passage of time that helps organisms to survive in that environment.