Even though marsupial mammals give birth to live young, an eggshell forms briefly early in their development. This is evidence that a.marsupials share a common ancestor with some egg-laying species; b. marsupials are not really mammals; c. all animals arose from a common ancestor; d. marsupial mammals were separately created by God; e. the fossil record of marsupial mammals is incorrect

Verified step by step guidance

1. Identify the key biological process mentioned: the formation of an eggshell briefly during the development of marsupial mammals.
2. Understand the significance of eggshell formation: This suggests a reproductive link or similarity with egg-laying species.
3. Analyze the options by linking them with evolutionary biology concepts: Consider which option suggests a shared evolutionary trait or common ancestry.
4. Evaluate the option that suggests a common ancestry with egg-laying species, as this would explain the transient eggshell formation in marsupials.
5. Eliminate options that do not align with evolutionary biology principles or that introduce concepts not supported by scientific evidence.

Key Concepts

Common Ancestry

Common ancestry refers to the idea that different species share a common ancestor from which they evolved. This concept is fundamental in evolutionary biology, as it explains the similarities and differences among species. The presence of shared traits, such as the temporary formation of an eggshell in marsupials, supports the notion that marsupials and egg-laying species diverged from a common lineage.

Evolutionary Development

Evolutionary development, or evolutionary developmental biology (evo-devo), studies how developmental processes evolve and how they contribute to the diversity of life. In marsupials, the brief formation of an eggshell during early development suggests evolutionary adaptations that may have arisen from ancestral traits. Understanding these developmental processes helps clarify the evolutionary relationships among different groups of animals.

Mammalian Classification

Mammalian classification categorizes animals based on shared characteristics, such as mammary glands and live birth in most species. Marsupials, a subgroup of mammals, exhibit unique reproductive traits, including giving birth to underdeveloped young that continue to develop in a pouch. Recognizing marsupials as true mammals is essential for understanding their evolutionary significance and their relationship to other mammalian groups.