Molecular evidence for evolutionary relationships examples | High school biology | Khan Academy

TL;DR

Investigating the similarities and differences in enzyme presence, amino acid sequences, and gel electrophoresis banding patterns to determine the closest plant species and evolutionary relationships between finches.

Transcript

• [Instructor] An investigation was carried out on four different plant species to determine which of three species was most closely related to an unknown plant species. The results of the investigation are shown in the data table below. Which plant species appears to be most closely related to the unknown species? Support your answer. So pause thi... Read More

Key Insights

• 😇 Enzyme presence, amino acid sequences, and gel electrophoresis banding patterns can be used to identify the closest plant species to an unknown species.
• ❓ Species demonstrating the same banding pattern as the unknown species and fewer differences in amino acid sequences are likely to be more closely related.
• 😇 Molecular evidence obtained from DNA analysis using gel electrophoresis is crucial in determining evolutionary relationships between different species.
• 👻 Gel electrophoresis allows for the comparison of DNA banding patterns, indicating genetic similarities and providing insights into evolutionary relationships.

Questions & Answers

Q: How was the plant species most closely related to the unknown species identified?

The plant species most closely related to the unknown species was identified by considering enzyme presence, amino acid sequences, and gel electrophoresis banding patterns. Species two demonstrated the same banding pattern as the unknown species, fewer differences in amino acid sequences, and tested positive for Enzyme M.

Q: What method was used to determine the evolutionary relationships between the finch species?

The method used to determine the evolutionary relationships between the finch species involved obtaining molecular evidence from all three species and identifying similarities. DNA analysis through gel electrophoresis was used to compare banding patterns and analyze the genetic similarities between the species.

Q: Why was species two considered the leading candidate in the plant species investigation?

Species two was considered the leading candidate in the plant species investigation because it had the same banding pattern as the unknown species, suggesting a close evolutionary relationship. Additionally, it had fewer differences in amino acid sequences compared to species three.

Q: How does gel electrophoresis help in determining evolutionary relationships?

Gel electrophoresis helps in determining evolutionary relationships by allowing the comparison of banding patterns created by DNA fragments. Similar banding patterns indicate genetic similarities and suggest a more recent common ancestor, providing insights into the evolutionary relationships between species.

Summary & Key Takeaways

• An investigation was conducted to identify the plant species most closely related to an unknown species by analyzing enzyme presence, amino acid sequences, and gel electrophoresis banding patterns.

• Species two appears to be the most closely related to the unknown species based on having the same banding pattern, fewer differences in amino acid sequences, and testing positive for Enzyme M.

• In the finch evolutionary relationships study, molecular evidence from DNA analysis using gel electrophoresis was used to identify similarities and determine the relationships between species.