The discovery of _____ helped scientists determine the phylogeny of amniotes?
A) external fertilization
B) temporal skull holes
C) Water-permeable eggs with no shells
D) Both A and C
The correct answer is D) Both A and C.
To determine the phylogeny of amniotes, scientists considered two key characteristics: external fertilization and water-permeable eggs with no shells.
To get the answer, you can start by understanding what external fertilization and water-permeable eggs with no shells are and why they are significant in determining phylogeny.
External fertilization refers to reproduction that occurs outside the body, where the male deposits sperm on the female's eggs. This is different from internal fertilization, which is the case in most mammals where fertilization happens inside the female's body. External fertilization is an ancestral trait found in many early vertebrates.
Water-permeable eggs with no shells are eggs that do not have a protective hard shell and allow water exchange with the environment. This characteristic is also ancestral in vertebrates.
Both external fertilization and water-permeable eggs with no shells are traits found in certain groups of amniotes, specifically in early reptiles and amphibians. Thus, the presence of these characteristics helps scientists determine the phylogeny of amniotes.
By considering these traits, scientists can trace the evolutionary history and relationships of amniotes, understanding how different groups are related and how they evolved over time.
After understanding the concept of external fertilization, water-permeable eggs with no shells, and their significance in determining phylogeny, you can conclude that the correct answer is D) Both A and C.