Why Are Dogs More Diverse Than Cats Despite Genetics?

TL;DR

Dogs appear more diverse than cats in physical traits due to selective breeding, yet they have less genetic diversity overall. While dogs are genetically similar within breeds due to centuries of breeding practices, cats maintain more genetic variation across the species despite the lack of defined breeds. This disparity raises questions about the future of breeding practices for both animals.

Transcript

Hi, this is Kate from MinuteEarth. And my dog Watson looks like this. But there are also dogs that look like this. And this. And this and this and this. They’re so different that they barely seem like the same species. While there are some definite weirdos in the feline world, cats generally look - and act - much more similar to each other than dog... Read More

Key Insights

• 😺 Dogs are visually diverse due to selective breeding, but genetically, they are less diverse than cats.
• 🤵 Selective breeding has grouped different genes and variants into specific dog breeds, making them genetically similar within a breed.
• 😺 Cats have more genetic diversity overall, but their breed categories are less well-defined, resulting in less genetic similarity within breeds.
• ❓ Humans have more genetic variation between populations than within a population.
• 🤵 A few specific genes have a disproportionate impact on dogs' physical characteristics, such as size.
• 🤵 Dogs are not unique in terms of breeding for size differences; chickens and plants like Brassica oleracea have also been selectively bred for size variation.
• 😺 Cats could potentially be bred to exhibit more variation in the future, but the consequences and ethical considerations need to be taken into account.

Questions & Answers

Q: Why do dogs appear more diverse than cats despite their genetic uniformity?

Dogs have been selectively bred for specific traits, resulting in different genes and variants being grouped together in specific breeds. This creates distinct physical and behavioral characteristics that make them appear more diverse.

Q: How does genetic diversity in cats compare to dogs?

Cats have more genetic diversity overall, but their breed categories are less defined. Within a breed, cats are not genetically similar, but there is some genetic similarity across different breeds.

Q: Can cats be bred to have the same level of variation as dogs in the future?

With careful selection over time, it is possible to breed cats that exhibit as much variation as dogs. However, the consequences and potential drawbacks of breeding giant cats need to be considered before pursuing such endeavors.

Q: What role do specific genes play in determining certain traits in dogs?

Only a few genes, around 14, contribute to the majority of variations in dogs' size. In contrast, humans have hundreds of genes influencing traits like height and BMI.

Summary & Key Takeaways

• Dogs exhibit a wide range of physical and behavioral differences, but genetically, they are surprisingly uniform compared to cats.

• Through centuries of selective breeding, different genes and variants have been consolidated into specific dog breeds, making them genetically similar within their breed.

• Cats, on the other hand, have more overall genetic diversity, but their breed categories are less well-defined, resulting in less genetic similarity within breeds and more similarity across different breeds.