Question

What's a major assumption when drawing evolutionary relationships between organisms?

Answer 1

The major assumption when drawing evolutionary relationships between organisms is that more closely related organisms will look more alike, although this is not always true due to environmental factors and adaptations.

Step-by-step explanation:

A major assumption when drawing evolutionary relationships between organisms is that more closely related organisms will look more alike. However, this assumption is not always true. If two closely related lineages evolved under significantly different surroundings or after the evolution of a major new adaptation, they may look quite different from each other, even more so than other groups that are not as closely related. For example, a phylogenetic tree may show that lizards and frogs appear more similar than lizards and rabbits, even though lizards and rabbits are more closely related.

Answer 2

Based on DNA sequences, it is believed that changes in nucleotide sequence between two species are equivalent to the time that has elapsed since the two species diverged from their common ancestor. Gene sequencing is being used in addition to morphology to determine evolutionary relationships between organism. Homologous sequences show greater evolutionary relationship