Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Embryology is the study of how organisms develop from fertilized eggs. When scientists compare embryos from different vertebrates - like fish, turtles, chickens, and humans - they observe remarkable similarities in their early stages.
For example, all vertebrate embryos start with a notochord (a flexible rod that later becomes the spine), pharyngeal arches (gill-like structures near the throat), and a post-anal tail. Although these structures develop into different adult forms - gills in fish, ear and throat bones in humans - their presence in embryos provides evidence of shared ancestry.
In later stages, embryos diverge as species develop specialized features. A turtle embryo forms a shell, a chick forms wings, and a human embryo forms arms and legs. This progression reflects how evolution modifies a common developmental plan rather than inventing new structures from scratch.
Comparing embryos across species also shows how small genetic changes can lead to major differences. For instance, slight variations in gene expression timing can transform a limb bud into a wing, fin, or hand. This demonstrates the concept of homology at the developmental level - structures built from the same embryonic tissues, adapted for different functions.
Today, genetic evidence supports what embryology first suggested: all vertebrates share deep developmental similarities because they inherited their body plan from a common ancestor that lived over 500 million years ago.
Graph of Information - Figure 1.
Graph of Information - Figure 2.
Figure 3.
Figure 4.
Using Table 1, compare the presence of the notochord, pharyngeal arches, and post-anal tail across all four vertebrate embryos. What pattern do you observe?
Explain why different vertebrate embryos all begin development with similar structures even though they grow into very different adult forms.
According to Table 1, which species has the smallest yolk sac during early development?
Based on Table 2, which species shows the largest decrease in developmental score from early to late stages?
Does the embryology data support the claim that vertebrates share a common ancestor?
Claim:
Evidence:
Reasoning:
Using Table 1, compare limb bud development among the four embryos. What does this suggest about how limbs evolve into fins, wings, or hands?