Question

Which of the following is not evidence for evolution ?

• A. Divergent evolution of anatomical structures such as forelimbs
• B. Convergent evolution of traits like wings of birds and butterflies
• C. Paleontological evidence from fossil records
• D. Embryological support for evolution as proposed by Ernst Heckel

Hint:

• Karl Ernst von Baer's careful observations of vertebrate embryology led to the rejection of the "recapitulation theory," establishing that embryonic stages do not recapitulate adult ancestral forms.

• Homology represents common ancestry with divergent functions, while analogy represents separate ancestries with convergent functions.

Answer 1

The Correct Option is D

Concept:

• Evolutionary biology relies on several independent lines of evidence to reconstruct the history of life on Earth, including: itemize

• Anatomical Evidence: Homologous organs (arising from divergent evolution) and analogous organs (arising from convergent evolution).

• Paleontological Evidence: Morphological structures preserved in fossil records.

• Embryological Evidence: Comparative analyses of early developmental stages of organisms.
The biogenetic law ("ontogeny recapitulates phylogeny") proposed by Ernst Haeckel (spelled "Heckel" in the question) stated that embryonic development mirrors the adult stages of evolutionary ancestors. This theory was contested and rejected by other embryologists. itemize

Step 1: Evaluate the valid lines of evolutionary evidence

• Option (A): Divergent evolution of homologous structures (e.g., the anatomy of forelimbs in whales, bats, cheetahs, and humans) demonstrates adaptation from a common ancestral form.

• Option (B): Convergent evolution of analogous structures (e.g., wings of birds and butterflies) demonstrates adaptation to similar environments from different ancestral lineages.

• Option (C): Paleontological studies (fossil records) provide physical historical evidence of structural transitions and lineages.
These three options represent established and validated categories of evolutionary evidence.

Step 2: Analyze the scientific status of Haeckel's embryological theory
Ernst Haeckel proposed that human and animal embryos pass through the fully formed adult stages of their evolutionary ancestors. However, this assertion was challenged by Karl Ernst von Baer, who demonstrated that embryos of different species do not pass through adult stages of other species, but rather diverge along distinct developmental pathways. Consequently, Haeckel's specific theory of embryological recapitulation is not accepted as valid scientific evidence. This corresponds to option (D).