Fins, limbs, and the origin of morphological novelty | Summary and Q&A

TL;DR

Dr. Tom Stewart discusses the evolution of fins into limbs, focusing on the dermal fin rays and their asymmetrical development.

Key Insights

• 🖐️ The fin to limb transition occurred about 365 million years ago in epistegalians, involving the origin of digits and the loss of the fin web.
• 💦 Most research has focused on the evolution of the endoskeleton, but Dr. Stewart's work examines the diversity and evolution of dermal fin rays.
• 🖐️ The analysis of dermal fin rays reveals asymmetry in their distribution, indicating adaptations for maintaining an upright posture and supporting body weight.

Transcript

so it's um now my honor to introduce the second half of the session on translation engineering computational biology and precision medicine and we're going to hear from three talented scientists in this session dr tom stewart from the university of chicago and the field museum of natural history dr miray camariza a junior fellow at the society of f... Read More

Questions & Answers

Q: What is Dr. Tom Stewart's area of expertise?

Dr. Tom Stewart is an evolutionary and developmental biologist specializing in the fin to limb transition.

Q: What is the significance of analyzing dermal fin rays?

Analyzing dermal fin rays provides insights into the evolution and biomechanics of fins and their transformation into limbs.

Q: What does the asymmetrical distribution of fin rays suggest?

The asymmetry in fin ray distribution indicates that the animal had a fleshy palm, allowing it to maintain an upright posture and support its body against the substrate.

Q: How is this research relevant to other fields?

The research has implications for biomechanics and the design of flexible propulsors in aquatic robots. It also provides insights into the patterning of limbs and the role of specific genes in their development.

Q: How does Dr. Stewart study the evolution of fins to limbs?

He uses CT scanning technology to digitally dissect and analyze specimens, revealing the endoskeleton and dermal fin rays, as well as reconstructing the total fin anatomy.

Summary & Key Takeaways

• Dr. Tom Stewart is an evolutionary and developmental biologist interested in explaining the diversity of biological structures.

• He focuses on the fin to limb transition, specifically analyzing the diversity and evolution of dermal fin rays.

• Using CT scanning technology, he studies the pectoral fins of tetrapodomorph fishes and discovers asymmetrical patterns in the distribution of fin rays.